Hi,

Does any one know how to extract the envelope of an amplitude modulated
signal without a phase shift, distortions, and able to determine the
envelope in between the signal cycles. One way that almost works is to
simply devide the signal by the carrier but, this technique is too
sensitive to phase noise. I have also tried using the Hilbert transform
but, I get some leakage distortions.

Thanks

WWalker wrote:
> Hi,
> 
> Does any one know how to extract the envelope of an amplitude modulated
> signal without a phase shift, distortions, and able to determine the
> envelope in between the signal cycles. One way that almost works is to
> simply devide the signal by the carrier but, this technique is too
> sensitive to phase noise. I have also tried using the Hilbert transform
> but, I get some leakage distortions.

Extracting the envelope of an AM signal is called "demodulation" or less 
rigorously, "detection". There are many reasons for dividing by the 
carrier not working, but extreme non-linearity is probably the best one.

What do you do with your Hilbert transform? It is part of a technique 
that works very well provided the needed computation can be done in time.

Jerry
-- 
It matters little to a goat whether it be dedicated to God or consigned
to Azazel. The critical turning was having been chosen to participate.
�����������������������������������������������������������������������

On Mar 7, 10:37=A0pm, Jerry Avins <j...@ieee.org> wrote:
> WWalker wrote:
> > Hi,
>
> > Does any one know how to extract the envelope of an amplitude modulated
> > signal without a phase shift, distortions, and able to determine the
> > envelope in between the signal cycles. One way that almost works is to
> > simply devide the signal by the carrier but, this technique is too
> > sensitive to phase noise. I have also tried using the Hilbert transform
> > but, I get some leakage distortions.
>
> Extracting the envelope of an AM signal is called "demodulation" or less
> rigorously, "detection". There are many reasons for dividing by the
> carrier not working, but extreme non-linearity is probably the best one.

dunno why you can't rectify (abs value) and LPF.  unless overmodulated
or it's suppressed carrier.

> What do you do with your Hilbert transform? It is part of a technique
> that works very well provided the needed computation can be done in time.

one thing i would like to figure out is what the OP means by "without
phase shift".  if he/she means no delay in the detection alg, then
Hilbert is out of the picture completely.

r b-j

robert bristow-johnson wrote:
> On Mar 7, 10:37 pm, Jerry Avins <j...@ieee.org> wrote:
>> WWalker wrote:
>>> Hi,
>>> Does any one know how to extract the envelope of an amplitude modulated
>>> signal without a phase shift, distortions, and able to determine the
>>> envelope in between the signal cycles. One way that almost works is to
>>> simply devide the signal by the carrier but, this technique is too
>>> sensitive to phase noise. I have also tried using the Hilbert transform
>>> but, I get some leakage distortions.
>> Extracting the envelope of an AM signal is called "demodulation" or less
>> rigorously, "detection". There are many reasons for dividing by the
>> carrier not working, but extreme non-linearity is probably the best one.
> 
> dunno why you can't rectify (abs value) and LPF.  unless overmodulated
> or it's suppressed carrier.

What guarantee is there that the sample instants will coincide with the 
peaks of the carrier? It's conceivable (but most unlikely) that all the 
samples will nearly coincide with zero crossings of the carrier.

>> What do you do with your Hilbert transform? It is part of a technique
>> that works very well provided the needed computation can be done in time.
> 
> one thing i would like to figure out is what the OP means by "without
> phase shift".  if he/she means no delay in the detection alg, then
> Hilbert is out of the picture completely.

I would like to understand what dividing by the carrier would do. I 
almost get it, but the carrier is zero twice a cycle.

Jerry
-- 
It matters little to a goat whether it be dedicated to God or consigned
to Azazel. The critical turning was having been chosen to participate.
�����������������������������������������������������������������������

>WWalker wrote:
>> Hi,
>> 
>> Does any one know how to extract the envelope of an amplitude modulated
>> signal without a phase shift, distortions, and able to determine the
>> envelope in between the signal cycles. One way that almost works is to
>> simply devide the signal by the carrier but, this technique is too
>> sensitive to phase noise. I have also tried using the Hilbert transform
>> but, I get some leakage distortions.
>
>Extracting the envelope of an AM signal is called "demodulation" or less 
>rigorously, "detection". There are many reasons for dividing by the 
>carrier not working, but extreme non-linearity is probably the best one.
>
>What do you do with your Hilbert transform? It is part of a technique 
>that works very well provided the needed computation can be done in time.
>
>Jerry
>-- 
>It matters little to a goat whether it be dedicated to God or consigned
>to Azazel. The critical turning was having been chosen to participate.
----------------------------------------------------
>
First I should say I am tryting to extract the envelope of an amplitude
modulated signal that has been captured by an oscilloscope. I am doing some
wave propagation experiments and I need to measure the time delay of the
envelope very accurately. As you mentioned, dividing by the carrier is not
a good way to do it, but it does demonstrate that it should be possible to
come up with a technique to extract the envelope without a phase shift of
the envelope, negligible distortions, and able to determine the envelope in
between signal cycles. 

Regarding the Hilbert Transform method, I squared the signal and added it
to the square of the Hilbert transform of the signal. Then I took the
square root of the result. This technique extracts the envelope without a
phase shift, but it does introduce problematic oscillations near the
beginning and end of the signal. I do not want to use a filter to get rid
of the oscillations because it will add a phase shift to the envelope. 

Another method I am considering is to curvefit the known form of the AM
signal, provided the everything is known about the signal except the unkown
modulation amplitude. But I am not sure if this technnique will work with
real signals that have some noise.

William

>robert bristow-johnson wrote:

>I would like to understand what dividing by the carrier would do. I 
>almost get it, but the carrier is zero twice a cycle.
>
>Jerry
-----------------------------------

Given an AM signal: Sig = A Cos[wm t]*Cos[wc t]. Then the modulation
envelope can be obtained by simple dividing by the carrier:
Sig/Cos[wc t] = A Cos[wm t]. But the problem is that when the carrier goes
to zero the result goes to infinity. One way arround the problem is to add
an offset to the carrier so that the carrier never goes to zero, but this
completely changes the signal.

William

>On Mar 7, 10:37=A0pm, Jerry Avins <j...@ieee.org> wrote:

>one thing i would like to figure out is what the OP means by "without
>phase shift".  if he/she means no delay in the detection alg, then
>Hilbert is out of the picture completely.
>
>r b-j
------------------------
I simply want a very good match when I overlay the AM Signal with the
calculated envelope. In order for this to work the calculated envelope can
not be phase shifted.

William

> Regarding the Hilbert Transform method, I squared the signal and added it
> to the square of the Hilbert transform of the signal. Then I took the
> square root of the result. This technique extracts the envelope without a
> phase shift, but it does introduce problematic oscillations near the
> beginning and end of the signal. I do not want to use a filter to get rid
> of the oscillations because it will add a phase shift to the envelope.

Both I and Q components shall be fed through the same low pass filter
that your Hilbert filter was designed from. From your description it
seems like your I component is fed directly without low pass
filtering.

Maybe the oscillation is an effect the impulse response of your low
pass filter?

Vojtech

WWalker wrote:
>> robert bristow-johnson wrote:
> 
>> I would like to understand what dividing by the carrier would do. I 
>> almost get it, but the carrier is zero twice a cycle.
>>
>> Jerry
> -----------------------------------
> 
> Given an AM signal: Sig = A Cos[wm t]*Cos[wc t]. Then the modulation
> envelope can be obtained by simple dividing by the carrier:
> Sig/Cos[wc t] = A Cos[wm t]. But the problem is that when the carrier goes
> to zero the result goes to infinity. One way arround the problem is to add
> an offset to the carrier so that the carrier never goes to zero, but this
> completely changes the signal.

I understand the math, but I don't understand the process. the OP 
implied that the method works in the absence of significant noise. It 
must have been a Matlab solution. Otherwise, where would he have gotten 
a bit-accurate replica of the unmodulated carrier?

Jerry
-- 
It matters little to a goat whether it be dedicated to God or consigned
to Azazel. The critical turning was having been chosen to participate.
�����������������������������������������������������������������������

WWalker wrote:
>> On Mar 7, 10:37=A0pm, Jerry Avins <j...@ieee.org> wrote:
> 
>> one thing i would like to figure out is what the OP means by "without
>> phase shift".  if he/she means no delay in the detection alg, then
>> Hilbert is out of the picture completely.
>>
>> r b-j
> ------------------------
> I simply want a very good match when I overlay the AM Signal with the
> calculated envelope. In order for this to work the calculated envelope can
> not be phase shifted.

Of course it can. Delay the signal an equal amount.

Jerry
-- 
It matters little to a goat whether it be dedicated to God or consigned
to Azazel. The critical turning was having been chosen to participate.
�����������������������������������������������������������������������

WWalker wrote:

>>robert bristow-johnson wrote:
> 
> 
>>I would like to understand what dividing by the carrier would do. I 
>>almost get it, but the carrier is zero twice a cycle.
>>
>>Jerry
> 
> -----------------------------------
> 
> Given an AM signal: Sig = A Cos[wm t]*Cos[wc t]. Then the modulation
> envelope can be obtained by simple dividing by the carrier:
> Sig/Cos[wc t] = A Cos[wm t].

JFYI: AM = A [1 + M cos (wm t)] cos (wc t)

> But the problem is that when the carrier goes
> to zero the result goes to infinity. One way arround the problem is to add
> an offset to the carrier so that the carrier never goes to zero, but this
> completely changes the signal.

You do weird things in the weird ways.

VLV

WWalker wrote:
>> WWalker wrote:
>>> Hi,
>>>
>>> Does any one know how to extract the envelope of an amplitude modulated
>>> signal without a phase shift, distortions, and able to determine the
>>> envelope in between the signal cycles. One way that almost works is to
>>> simply devide the signal by the carrier but, this technique is too
>>> sensitive to phase noise. I have also tried using the Hilbert transform
>>> but, I get some leakage distortions.
>> Extracting the envelope of an AM signal is called "demodulation" or less 
>> rigorously, "detection". There are many reasons for dividing by the 
>> carrier not working, but extreme non-linearity is probably the best one.
>>
>> What do you do with your Hilbert transform? It is part of a technique 
>> that works very well provided the needed computation can be done in time.
>>
>> Jerry
>> -- 
>> It matters little to a goat whether it be dedicated to God or consigned
>> to Azazel. The critical turning was having been chosen to participate.
> ----------------------------------------------------
> First I should say I am tryting to extract the envelope of an amplitude
> modulated signal that has been captured by an oscilloscope. I am doing some
> wave propagation experiments and I need to measure the time delay of the
> envelope very accurately. As you mentioned, dividing by the carrier is not
> a good way to do it, but it does demonstrate that it should be possible to
> come up with a technique to extract the envelope without a phase shift of
> the envelope, negligible distortions, and able to determine the envelope in
> between signal cycles. 

Any operation takes time, thus incurring a delay which, at any given 
frequency, is a phase shift. Working with captured data, that doesn't 
matter. (Think of the phase shifts caused by a CD between the recording 
studio and the listener!) In any event, if you want to see the result of 
a difference between group- and phase velocities, the shift that matters 
is between the envelope and the carrier. You have to compare the 
modulated signals before and after the passage through the dispersive 
medium. Then you will see a (probaby slight) shift of the peak of the 
envelope relative to a peak of the carrier.

> Regarding the Hilbert Transform method, I squared the signal and added it
> to the square of the Hilbert transform of the signal. Then I took the
> square root of the result. This technique extracts the envelope without a
> phase shift, but it does introduce problematic oscillations near the
> beginning and end of the signal. I do not want to use a filter to get rid
> of the oscillations because it will add a phase shift to the envelope. 

The quadrature signal that the HT creates is delayed. The original 
carrier providing the in-phase signal must be delayed an equal amount, 
of course. If your HT contains an odd number of taps, the signal at the 
middle tap will be a properly delayed in-phase signal. You could delay 
the carrier by that amount as well.

I assume that your HT is long enough and that you use a window 
(Nuttall?) if the coefficients are computed by simple formula. Every 
filter, for whatever purpose, has start and end transients. Only when a 
transversal filter is filled with actual data does it give the computed 
result you expect.

> Another method I am considering is to curvefit the known form of the AM
> signal, provided the everything is known about the signal except the unkown
> modulation amplitude. But I am not sure if this technnique will work with
> real signals that have some noise.

It probably wouldn't show what I think you want even if it did.

Jerry
-- 
Physics is like sex: sure, it may give some practical results, but
that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)
������������������������������������������������������������������������

Jerry Avins wrote:
> WWalker wrote:
>>> robert bristow-johnson wrote:
>>
>>> I would like to understand what dividing by the carrier would do. I 
>>> almost get it, but the carrier is zero twice a cycle.
>>>
>>> Jerry
>> -----------------------------------
>>
>> Given an AM signal: Sig = A Cos[wm t]*Cos[wc t]. Then the modulation
>> envelope can be obtained by simple dividing by the carrier:
>> Sig/Cos[wc t] = A Cos[wm t]. But the problem is that when the carrier 
>> goes
>> to zero the result goes to infinity. One way arround the problem is to 
>> add
>> an offset to the carrier so that the carrier never goes to zero, but this
>> completely changes the signal.
> 
> I understand the math, but I don't understand the process. the OP 
> implied that the method works in the absence of significant noise. It 
> must have been a Matlab solution. Otherwise, where would he have gotten 
> a bit-accurate replica of the unmodulated carrier?

Oops! you *are* the OP.

Jerry
-- 
Physics is like sex: sure, it may give some practical results, but
that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)
������������������������������������������������������������������������

WWalker wrote:
>> robert bristow-johnson wrote:
> 
>> I would like to understand what dividing by the carrier would do. I 
>> almost get it, but the carrier is zero twice a cycle.
>>
>> Jerry
> -----------------------------------
> 
> Given an AM signal: Sig = A Cos[wm t]*Cos[wc t]. Then the modulation
> envelope can be obtained by simple dividing by the carrier:
> Sig/Cos[wc t] = A Cos[wm t]. But the problem is that when the carrier goes
> to zero the result goes to infinity. One way arround the problem is to add
> an offset to the carrier so that the carrier never goes to zero, but this
> completely changes the signal.

W,

Let me use your suggestion of an offset to encourage you to think things 
through more thoroughly. The carrier varies from some peak positive 
value to a peak negative value of equal magnitude. The added "offset" 
must exceed this peak value in order to ensure that the sum is never 
zero. What does the math look like now?

Jerry
-- 
Physics is like sex: sure, it may give some practical results, but
that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)
������������������������������������������������������������������������

WWalker wrote:
> Hi,
> 
> Does any one know how to extract the envelope of an amplitude modulated
> signal without a phase shift, distortions, and able to determine the
> envelope in between the signal cycles. One way that almost works is to
> simply devide the signal by the carrier but, this technique is too
> sensitive to phase noise. I have also tried using the Hilbert transform
> but, I get some leakage distortions.

Multiplying by the carrier is an accepted and worthwhile practice. 
There are numerous useful extensions of this, many of which are to deal 
with the phase noise issue, and with selective fading that includes the 
carrier -- search on "exalted carrier" and "synchronous AM" to see the 
variations.

-- 
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Tim Wescott wrote:
> WWalker wrote:
>> Hi,
>>
>> Does any one know how to extract the envelope of an amplitude modulated
>> signal without a phase shift, distortions, and able to determine the
>> envelope in between the signal cycles. One way that almost works is to
>> simply devide the signal by the carrier but, this technique is too
>> sensitive to phase noise. I have also tried using the Hilbert transform
>> but, I get some leakage distortions.
> 
> Multiplying by the carrier is an accepted and worthwhile practice. There 
> are numerous useful extensions of this, many of which are to deal with 
> the phase noise issue, and with selective fading that includes the 
> carrier -- search on "exalted carrier" and "synchronous AM" to see the 
> variations.

I think W wants to explore the effects of a dispersive channel with 
constant group delay in the band of interest. I don't think any kind of 
demodulation is useful for that.

Jerry
-- 
Physics is like sex: sure, it may give some practical results, but
that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)
������������������������������������������������������������������������

On Mar 8, 5:57=A0am, "WWalker" <william.wal...@imtek.de> wrote:
> >On Mar 7, 10:37=3DA0pm, Jerry Avins <j...@ieee.org> wrote:
> >one thing i would like to figure out is what the OP means by "without
> >phase shift". =A0if he/she means no delay in the detection alg, then
> >Hilbert is out of the picture completely.
>
> >r b-j
>
> ------------------------
> I simply want a very good match when I overlay the AM Signal with the
> calculated envelope. In order for this to work the calculated envelope ca=
n
> not be phase shifted.
>
> William

When you say it can not be "phase shifted", do you include a simple
time delay (known number of samples) as a "phase shift"?

Dirk

On Mar 8, 2:53=A0pm, "WWalker" <william.wal...@imtek.de> wrote:
> Hi,
>
> Does any one know how to extract the envelope of an amplitude modulated
> signal without a phase shift, distortions, and able to determine the
> envelope in between the signal cycles. One way that almost works is to
> simply devide the signal by the carrier but, this technique is too
> sensitive to phase noise. I have also tried using the Hilbert transform
> but, I get some leakage distortions.
>
> Thanks

Use a PLL to get the carrier frequency and multiply and then low-pass
filter. Synchronous demodulation.
For supressed carrier you need to square the signal first then lock
onto 2f then divide by two and multiple - filter.
For low carrier to noise ratios you may need a different method.

Hardy

Hi Hardy,

Unfortunately, the LPF will phase shift the modulation. So this technique
will not work for me. Do you know of any other way to extract the
modulation without using a filter? 

William

>On Mar 8, 2:53=A0pm, "WWalker" <william.wal...@imtek.de> wrote:
>> Hi,
>>
>> Does any one know how to extract the envelope of an amplitude modulated
>> signal without a phase shift, distortions, and able to determine the
>> envelope in between the signal cycles. One way that almost works is to
>> simply devide the signal by the carrier but, this technique is too
>> sensitive to phase noise. I have also tried using the Hilbert transform
>> but, I get some leakage distortions.
>>
>> Thanks
>
>Use a PLL to get the carrier frequency and multiply and then low-pass
>filter. Synchronous demodulation.
>For supressed carrier you need to square the signal first then lock
>onto 2f then divide by two and multiple - filter.
>For low carrier to noise ratios you may need a different method.
>
>Hardy
>

On 21 Mar, 20:38, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi Hardy,
>
> Unfortunately, the LPF will phase shift the modulation. So this technique
> will not work for me.

That's a claim that needs justification. A lot of DSP newbies
and amateurs as similar questions as yours, because the term
"phase shift" somehow seems scary, imperfect, or awkward.

Too bad - it's a fact of life.

So make sure you understand *why* you want to avoid phase shifts:
"Sounds scary", "don't want to deal with them" or "don't understand
what they are or what causes them" are perfectly valid
*subjective* reasons.

Which, of course, can be attributed to poor education.

However, "phase shifts invalidates my analysis" is a totally
different cup of tea: It *sounds* as being objective (but is
almost always really caused by one or more of the subjective
reasons listed), and as such it requires objective, substantiated
arguments in support.

Rune

WWalker wrote:
> Hi Hardy,
> 
> Unfortunately, the LPF will phase shift the modulation. So this technique
> will not work for me. Do you know of any other way to extract the
> modulation without using a filter? 

Why do you believe that? Think about what is being filtered.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

In the system I am investigating, the phase speed and group speed are not
the same and are not constant and change with distance. Because of this,
the phase of the carrier is not the same as the phase of the modulation in
the signal. 

As I mentioned one way to get the modulation: without a phase shift,
without modulation distortion, and in between oscillations is to simply
divide the signal by the carrier which can be obtained by using a PLL.
Unfortunatly the technique is very sensitive to noise. But it does show
that it is in principle possible. The resultant modulation using the divide
technique is plagued with large random spikes. Do you know of any signal
processing methods to remove the spikes without distorting the signal or
phase shifting the modulation? I have tried using a running average, and
mean average but I always get a phase shift. Pehaps a Median filter could
be used but my guess is that it will distort the signal and phase shift
it.

Lastly, I should mention I have come up with another interesting method
which is to transmit a modulation signal through the dispersive medium with
a sinusoidal carrier (Q) and another modulation signal with a cosinusoidal
carrier (I). The instantaneous envelope can then be obtained by squaring
each, adding, and taking the square root. This method requires careful
alignment of the signals, but it does work and is a lot less sensitive to
noise.
 
William

>Tim Wescott wrote:
>> WWalker wrote:
>>> Hi,
>>>
>>> Does any one know how to extract the envelope of an amplitude
modulated
>>> signal without a phase shift, distortions, and able to determine the
>>> envelope in between the signal cycles. One way that almost works is to
>>> simply devide the signal by the carrier but, this technique is too
>>> sensitive to phase noise. I have also tried using the Hilbert
transform
>>> but, I get some leakage distortions.
>> 
>> Multiplying by the carrier is an accepted and worthwhile practice. There

>> are numerous useful extensions of this, many of which are to deal with 
>> the phase noise issue, and with selective fading that includes the 
>> carrier -- search on "exalted carrier" and "synchronous AM" to see the 
>> variations.
>
>I think W wants to explore the effects of a dispersive channel with 
>constant group delay in the band of interest. I don't think any kind of 
>demodulation is useful for that.
>
>Jerry
>-- 
>Physics is like sex: sure, it may give some practical results, but
>that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)
>������������������������������������������������������������������������
>

It looks like you don't know what you doing.
Matlab is not a substitute for knowledge.
 From here, you can either seek for professional help or study an ABC=20
book on DSP from cover to cover.

VLV


WWalker wrote:

> In the system I am investigating, the phase speed and group speed are n=
ot
> the same and are not constant and change with distance. Because of this=
,
> the phase of the carrier is not the same as the phase of the modulation=
 in
> the signal.=20
>=20
> As I mentioned one way to get the modulation: without a phase shift,
> without modulation distortion, and in between oscillations is to simply=

> divide the signal by the carrier which can be obtained by using a PLL.
> Unfortunatly the technique is very sensitive to noise. But it does show=

> that it is in principle possible. The resultant modulation using the di=
vide
> technique is plagued with large random spikes. Do you know of any signa=
l
> processing methods to remove the spikes without distorting the signal o=
r
> phase shifting the modulation? I have tried using a running average, an=
d
> mean average but I always get a phase shift. Pehaps a Median filter cou=
ld
> be used but my guess is that it will distort the signal and phase shift=

> it.
>=20
> Lastly, I should mention I have come up with another interesting method=

> which is to transmit a modulation signal through the dispersive medium =
with
> a sinusoidal carrier (Q) and another modulation signal with a cosinusoi=
dal
> carrier (I). The instantaneous envelope can then be obtained by squarin=
g
> each, adding, and taking the square root. This method requires careful
> alignment of the signals, but it does work and is a lot less sensitive =
to
> noise.
> =20
> William
>=20
>=20
>>Tim Wescott wrote:
>>
>>>WWalker wrote:
>>>
>>>>Hi,
>>>>
>>>>Does any one know how to extract the envelope of an amplitude
>=20
> modulated
>=20
>>>>signal without a phase shift, distortions, and able to determine the
>>>>envelope in between the signal cycles. One way that almost works is t=
o
>>>>simply devide the signal by the carrier but, this technique is too
>>>>sensitive to phase noise. I have also tried using the Hilbert
>=20
> transform
>=20
>>>>but, I get some leakage distortions.
>>>
>>>Multiplying by the carrier is an accepted and worthwhile practice. The=
re
>=20
>=20
>>>are numerous useful extensions of this, many of which are to deal with=
=20
>>>the phase noise issue, and with selective fading that includes the=20
>>>carrier -- search on "exalted carrier" and "synchronous AM" to see the=
=20
>>>variations.
>>
>>I think W wants to explore the effects of a dispersive channel with=20
>>constant group delay in the band of interest. I don't think any kind of=
=20
>>demodulation is useful for that.
>>
>>Jerry
>>--=20
>>Physics is like sex: sure, it may give some practical results, but
>>that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)=

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=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=
=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=
=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=
=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=
=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=
=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD=FF=CF=CD
>>

Hi Jerry, 

The low pass filter is used to filter out the higher harmonic terms
generated by the mixer. But unfortunately, the filter phase shifts the
wanted modulation. In my experiment I am transmitting a 50MHz Modulation
signl with a 500MHz Carrier. If I use a simple 3rd order filter
(1/(j(f/fc)+1)^3), with a 100MHz cutoff, the resultant modulation is phase
shifted about 90 degrees. But, the effect I am trying to measure is a 3
degree change in modulation.  

William



>
>Use a PLL to get the carrier frequency and multiply and then low-pass
>filter. Synchronous demodulation.
>For supressed carrier you need to square the signal first then lock
>onto 2f then divide by two and multiple - filter.
>For low carrier to noise ratios you may need a different method.
>
>Hardy
>


>WWalker wrote:
>> Hi Hardy,
>> 
>> Unfortunately, the LPF will phase shift the modulation. So this
technique
>> will not work for me. Do you know of any other way to extract the
>> modulation without using a filter? 
>
>Why do you believe that? Think about what is being filtered.
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

"WWalker" <william.walker@n_o_s_p_a_m.imtek.de> writes:

> Hi Hardy,
>
> Unfortunately, the LPF will phase shift the modulation. 

Not if you do it with a digital linear-phase filter.
-- 
Randy Yates                      % "So now it's getting late,
Digital Signal Labs              %    and those who hesitate
mailto://yates@ieee.org          %    got no one..."
http://www.digitalsignallabs.com % 'Waterfall', *Face The Music*, ELO

I am a professional. Say something intelligent and perhaps we can talk
about it. But being rude does not help.

William

>
>It looks like you don't know what you doing.
>Matlab is not a substitute for knowledge.
> From here, you can either seek for professional help or study an ABC=20
>book on DSP from cover to cover.
>
>VLV

I am *the* professional.
I need to know the problem statement. I.e. what is the input, what 
should be the output, what is the accuracy and what hardware is 
available. Your problem will probably take 3-4 hours of work. The cost 
is going to be $1000. Is this OK ?

Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com



WWalker wrote:

> I am a professional. Say something intelligent and perhaps we can talk
> about it. But being rude does not help.
> 
> William
> 
> 
>>It looks like you don't know what you doing.
>>Matlab is not a substitute for knowledge.
>>From here, you can either seek for professional help or study an ABC=20
>>book on DSP from cover to cover.
>>
>>VLV
> 
> 
> 

Hi Hardy,

A (FIR) linear phase filter will phase shift the modulation a small amount
without distorting the signal in the pass band. As I mentioned in a
previous post. I am trying to measure a 3 degree shift of a 50MHz
modulation, 500MHz carrier signal. 

But, I should mention, that the following technique does work. Fourier
Transform the signal. Replace the higher harmonics mixer terms with zeros,
and then inverse Fourier Transform back to the time domain.

William




William

>"WWalker" <william.walker@n_o_s_p_a_m.imtek.de> writes:
>
>> Hi Hardy,
>>
>> Unfortunately, the LPF will phase shift the modulation. 
>
>Not if you do it with a digital linear-phase filter.
>-- 
>Randy Yates                      % "So now it's getting late,
>Digital Signal Labs              %    and those who hesitate
>mailto://yates@ieee.org          %    got no one..."
>http://www.digitalsignallabs.com % 'Waterfall', *Face The Music*, ELO
>

On 21 Mar, 23:15, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> In the system I am investigating, the phase speed and group speed are not
> the same and are not constant and change with distance. Because of this,
> the phase of the carrier is not the same as the phase of the modulation in
> the signal.

If the phase and group velocities are different, the
system is dispersive. If you have a dispersive system,
you are in far worse trouble than a mere filter or
AM demodulator, irrespective of phase responses, can
handle.

What are you doing? What do you want to achieve?
Why do you think *you* are able to handle whatever it
is you are up to?

Rune

Vladimir, 

Thanks for the offer. I will think about it. In the meantime I would like
to know if there are solutions for this type of problem. From my experience
this is not an easy problem to solve and may require comming up with
something new as I have indicated in my posts. The problem is to measure a
3 degree change in the envelope of an AM Signal (50MHz modulation, 500MHz
Carrier) captured on a 1GHz digital scope. The envelope needs to be
extracted from the signal and compared to the envelope before the signal
propagated. I am trying to measure the group speed. 

William

>
>
>I am *the* professional.
>I need to know the problem statement. I.e. what is the input, what 
>should be the output, what is the accuracy and what hardware is 
>available. Your problem will probably take 3-4 hours of work. The cost 
>is going to be $1000. Is this OK ?
>
>Vladimir Vassilevsky
>DSP and Mixed Signal Design Consultant
>http://www.abvolt.com
>
>
>
>WWalker wrote:
>
>> I am a professional. Say something intelligent and perhaps we can talk
>> about it. But being rude does not help.
>> 
>> William
>> 
>> 
>>>It looks like you don't know what you doing.
>>>Matlab is not a substitute for knowledge.
>>>From here, you can either seek for professional help or study an ABC=20
>>>book on DSP from cover to cover.
>>>
>>>VLV
>> 
>> 
>> 
>

Rune Allnor <allnor@tele.ntnu.no> wrote:
> On 21 Mar, 23:15, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
> wrote:
>> In the system I am investigating, the phase speed and group speed are not
>> the same and are not constant and change with distance. Because of this,
>> the phase of the carrier is not the same as the phase of the modulation in
>> the signal.
 
> If the phase and group velocities are different, the
> system is dispersive. If you have a dispersive system,
> you are in far worse trouble than a mere filter or
> AM demodulator, irrespective of phase responses, can
> handle.

Note that the previous post indicated that they "change with
distance".  It is possible to have a system where they vary
in such a way that the overall system is not dispersive.

One way this has been done in optical systems is with a
phase conjugate mirror.  After a signal goes through a dispersive
medium (such as optical fiber), it then goes through a phase
conjugation device.  That reverses the effect such that passing
through the same amount of fiber restores the original signal.
That is, dispersive fiber+phase conjugation+dispersive fiber
is, overall, not dispersive!
 
> What are you doing? What do you want to achieve?
> Why do you think *you* are able to handle whatever it
> is you are up to?

Now that is a good question!

-- glen

Hi Rune,

Although the system is dispersive, provided the phase and amplitude reponse
of the system are linear over the bandwidth of the signal, the signal will
propagate undistorted. This is satisfied in my system with a 50MHz
Modulation, 500MHz Carrier AM signal. I simply want to measure a predicted
3 degree phase shift of the Modulation. In order to do that I need to
extract the modulation and compare it to the modulation before the
propagation. I do not know if this can be done. This is why I am asking. 

William




>On 21 Mar, 23:15, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> In the system I am investigating, the phase speed and group speed are
not
>> the same and are not constant and change with distance. Because of
this,
>> the phase of the carrier is not the same as the phase of the modulation
in
>> the signal.
>
>If the phase and group velocities are different, the
>system is dispersive. If you have a dispersive system,
>you are in far worse trouble than a mere filter or
>AM demodulator, irrespective of phase responses, can
>handle.
>
>What are you doing? What do you want to achieve?
>Why do you think *you* are able to handle whatever it
>is you are up to?
>
>Rune
>

Hi Glen,

I am simply trying to measure the group speed of a dispersive system by
transmitting an AM signal (50MHz modulation, 500MHz carrier) and comparing
the modulation before and after the signal has propagated. The signal is
expected to shift by about 3 degrees and it is not expected to distort as
it propagates.

William

>Rune Allnor <allnor@tele.ntnu.no> wrote:
>> On 21 Mar, 23:15, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>> wrote:
>>> In the system I am investigating, the phase speed and group speed are
not
>>> the same and are not constant and change with distance. Because of
this,
>>> the phase of the carrier is not the same as the phase of the modulation
in
>>> the signal.
> 
>> If the phase and group velocities are different, the
>> system is dispersive. If you have a dispersive system,
>> you are in far worse trouble than a mere filter or
>> AM demodulator, irrespective of phase responses, can
>> handle.
>
>Note that the previous post indicated that they "change with
>distance".  It is possible to have a system where they vary
>in such a way that the overall system is not dispersive.
>
>One way this has been done in optical systems is with a
>phase conjugate mirror.  After a signal goes through a dispersive
>medium (such as optical fiber), it then goes through a phase
>conjugation device.  That reverses the effect such that passing
>through the same amount of fiber restores the original signal.
>That is, dispersive fiber+phase conjugation+dispersive fiber
>is, overall, not dispersive!
> 
>> What are you doing? What do you want to achieve?
>> Why do you think *you* are able to handle whatever it
>> is you are up to?
>
>Now that is a good question!
>
>-- glen
>

Hi WWalker,

"WWalker" <william.walker@n_o_s_p_a_m.imtek.de> writes:

> Hi Hardy,

My name is Randy. 

> A (FIR) linear phase filter will phase shift the modulation 

Your choice of terms do not make sense to me.  "Modulation" doesn't get
"phase shifted" by a specific number of degrees; rather, a specific
frequency component of a signal gets phase shifted by some number of
degrees.

If you're actually referring to time delay, then I'd use the
term "time delay" and not "phase shift." 
-- 
Randy Yates                      % "So now it's getting late,
Digital Signal Labs              %    and those who hesitate
mailto://yates@ieee.org          %    got no one..."
http://www.digitalsignallabs.com % 'Waterfall', *Face The Music*, ELO

"WWalker" <william.walker@n_o_s_p_a_m.imtek.de> writes:

> Hi Hardy,
>
> A (FIR) linear phase filter will phase shift the modulation a small amount
> without distorting the signal in the pass band. As I mentioned in a
> previous post. I am trying to measure a 3 degree shift of a 50MHz
> modulation, 500MHz carrier signal. 

I see now from one of your previous responses that you are indeed
attempting to measure time delay.

There still should not be any problem whatsoever with using a
linear-phase FIR. Sure, it introduces a time delay, but the time delay
is constant and known and thus can be eliminated.
-- 
Randy Yates                      % "...the answer lies within your soul
Digital Signal Labs              %       'cause no one knows which side
mailto://yates@ieee.org          %                   the coin will fall."
http://www.digitalsignallabs.com %  'Big Wheels', *Out of the Blue*, ELO

WWalker wrote:
> In the system I am investigating, the phase speed and group speed are not
> the same and are not constant and change with distance. Because of this,
> the phase of the carrier is not the same as the phase of the modulation in
> the signal. 

Phase and group velocities are in general functions of frequency, but 
what kind of system makes the depend on distance? (To provide useful 
bandwidth, group velocity must be substantially constant --with or 
without equalization -- over the band of interest.)

> As I mentioned one way to get the modulation: without a phase shift,
> without modulation distortion, and in between oscillations is to simply
> divide the signal by the carrier which can be obtained by using a PLL.

The carrier goes to zero twice per cycle, even without noise. Division 
by zero is difficult when it can't be accomplished by algebraic 
cancellation of terms.

> Unfortunatly the technique is very sensitive to noise. But it does show
> that it is in principle possible. The resultant modulation using the divide
> technique is plagued with large random spikes. Do you know of any signal
> processing methods to remove the spikes without distorting the signal or
> phase shifting the modulation? I have tried using a running average, and
> mean average but I always get a phase shift. Pehaps a Median filter could
> be used but my guess is that it will distort the signal and phase shift
> it.
> 
> Lastly, I should mention I have come up with another interesting method
> which is to transmit a modulation signal through the dispersive medium with
> a sinusoidal carrier (Q) and another modulation signal with a cosinusoidal
> carrier (I). The instantaneous envelope can then be obtained by squaring
> each, adding, and taking the square root. This method requires careful
> alignment of the signals, but it does work and is a lot less sensitive to
> noise.

The dispersive medium delays upper and lower sidebands by different 
amounts of time. The envelope will be distorted by this differential 
delay no matter what demodulation scheme is used.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi

> William
> 
>> Tim Wescott wrote:
>>> WWalker wrote:
>>>> Hi,
>>>>
>>>> Does any one know how to extract the envelope of an amplitude
> modulated
>>>> signal without a phase shift, distortions, and able to determine the
>>>> envelope in between the signal cycles. One way that almost works is to
>>>> simply devide the signal by the carrier but, this technique is too
>>>> sensitive to phase noise. I have also tried using the Hilbert
> transform
>>>> but, I get some leakage distortions.
>>> Multiplying by the carrier is an accepted and worthwhile practice. There
> 
>>> are numerous useful extensions of this, many of which are to deal with 
>>> the phase noise issue, and with selective fading that includes the 
>>> carrier -- search on "exalted carrier" and "synchronous AM" to see the 
>>> variations.
>> I think W wants to explore the effects of a dispersive channel with 
>> constant group delay in the band of interest. I don't think any kind of 
>> demodulation is useful for that.
>>
>> Jerry
>> -- 
>> Physics is like sex: sure, it may give some practical results, but
>> that's not why we do it.   -- Richard P. Feynman (Nobel Prize, Physics)
>> ������������������������������������������������������������������������
>>


-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

WWalker wrote:
> I am a professional. Say something intelligent and perhaps we can talk
> about it. But being rude does not help.

Unfortunately, Vlad was accurate. Do the math.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

WWalker wrote:
> Hi Glen,
> 
> I am simply trying to measure the group speed of a dispersive system by
> transmitting an AM signal (50MHz modulation, 500MHz carrier) and comparing
> the modulation before and after the signal has propagated. The signal is
> expected to shift by about 3 degrees and it is not expected to distort as
> it propagates.

Then you want to test the path with two frequencies. An AM signal -- the 
kind that has an envelope -- has at least three frequencies. Consider 
what happens when the distance shifts the upper sideband -90 degrees and 
the upper sideband +90 degrees relative to the carrier. Then the 
envelope disappears and the signal becomes FM. (Undistorted FM if the 
original modulation percentage is low enough.) *Do the math*

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi

WWalker wrote:
> Hi Rune,
> 
> Although the system is dispersive, provided the phase and amplitude reponse
> of the system are linear over the bandwidth of the signal, the signal will
> propagate undistorted. This is satisfied in my system with a 50MHz
> Modulation, 500MHz Carrier AM signal. I simply want to measure a predicted
> 3 degree phase shift of the Modulation. In order to do that I need to
> extract the modulation and compare it to the modulation before the
> propagation. I do not know if this can be done. This is why I am asking. 

Of course it can. There will be delays due the processing, but they can 
be made equal for all components.

> William
> 
> 
> 
> 
>> On 21 Mar, 23:15, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>> wrote:
>>> In the system I am investigating, the phase speed and group speed are
> not
>>> the same and are not constant and change with distance. Because of
> this,
>>> the phase of the carrier is not the same as the phase of the modulation
> in
>>> the signal.
>> If the phase and group velocities are different, the
>> system is dispersive. If you have a dispersive system,
>> you are in far worse trouble than a mere filter or
>> AM demodulator, irrespective of phase responses, can
>> handle.
>>
>> What are you doing? What do you want to achieve?
>> Why do you think *you* are able to handle whatever it
>> is you are up to?
>>
>> Rune
>>

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

WWalker wrote:
> Hi Jerry, 
> 
> The low pass filter is used to filter out the higher harmonic terms
> generated by the mixer. But unfortunately, the filter phase shifts the
> wanted modulation. In my experiment I am transmitting a 50MHz Modulation
> signl with a 500MHz Carrier. If I use a simple 3rd order filter
> (1/(j(f/fc)+1)^3), with a 100MHz cutoff, the resultant modulation is phase
> shifted about 90 degrees. But, the effect I am trying to measure is a 3
> degree change in modulation.  

You are trying to isolate the carrier with the PLL. You can make a 
zero-degree lock.

> 
> 
> 
>> Use a PLL to get the carrier frequency and multiply and then low-pass
>> filter. Synchronous demodulation.
>> For supressed carrier you need to square the signal first then lock
>> onto 2f then divide by two and multiple - filter.
>> For low carrier to noise ratios you may need a different method.
>>
>> Hardy
>>
> 
> 
>> WWalker wrote:
>>> Hi Hardy,
>>>
>>> Unfortunately, the LPF will phase shift the modulation. So this
> technique
>>> will not work for me. Do you know of any other way to extract the
>>> modulation without using a filter? 
>> Why do you believe that? Think about what is being filtered.
>>
>> Jerry
>> -- 
>> Discovery consists of seeing what everybody has seen, and thinking what
>> nobody has thought.    .. Albert Szent-Gyorgi

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi

WWalker wrote:
> Hi Hardy,
> 
> A (FIR) linear phase filter will phase shift the modulation a small amount
> without distorting the signal in the pass band. As I mentioned in a
> previous post. I am trying to measure a 3 degree shift of a 50MHz
> modulation, 500MHz carrier signal. 
> 
> But, I should mention, that the following technique does work. Fourier
> Transform the signal. Replace the higher harmonics mixer terms with zeros,
> and then inverse Fourier Transform back to the time domain.

Phase shifts don't matter, only relative shifts. A symmetric FIR has 
none. You are fighting a phantom. Do the math.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 22 Mar, 00:55, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi Rune,
>
> Although the system is dispersive, provided the phase and amplitude reponse
> of the system are linear over the bandwidth of the signal, the signal will
> propagate undistorted. This is satisfied in my system with a 50MHz
> Modulation, 500MHz Carrier AM signal. I simply want to measure a predicted
> 3 degree phase shift of the Modulation. In order to do that I need to
> extract the modulation and compare it to the modulation before the
> propagation. I do not know if this can be done. This is why I am asking.

Why didn't you say that first time around?

You asked the wrong question. If you want to measure
dispersion, ask about how to measure dispersion, not
about how to measure obscure quantities that are
sensitive to most minute variations in initial
conditions or environment parameters.

In order to achieve what you want, the ideal set-up
is to measure the input and output simultaneously
and synchronously. If this is possible, estimate
the cross spectrum of the twu signals, and estimate
the phase.

If it is not possible to measure input and output
but you can use an array to measure the output, you
can still come up with an estimate of the phase
velocity.

The one thing *not* to do , is to work directly
with phase. But even if you want to do that, it
is perfectly possible to use a linear phase FIR
filter, and subtract the corresponding delay from
the filtered data.

But none of this matters until you have answered
the real question: Why would you want to verify
these predictions? What purpose could it possibly
serve? If you don't trust the maths - why not
verify it by measuring a quantity that is actually
possible to measure with any accuracy, is robust
to environmental variation, and can be processed?

Rune

Hi Rune,

The question you are asking is complicated but I will try to explain. I am
trying to measure the speed of information transmission in the nearfield of
a dipole source. This can be done by measuring the time delay of the
envelope of an AM signal between two dipole antennas. Theoretical
calculations show that the envelope should deviate about 3 degrees from
light speed for a 50MHz modulated, 500MHz carrier signal. 

I would like to capture the transmitted and received signal on a 1GHz
digital scope, extract the modulation envelopes, and measure the time
delay. In order to measure the speed of information propagation, I need to
also include the time it takes to demodulated the signal. Since the
modulation light speed deviation is expected to only occur within a
fraction (<1/10) of the carrier cycle, I need to come up with a
demodulation technique that does not use a filter. This is because a filter
takes more than a fraction of a carrier cycle to filter out the unwanted
signals. If you want more detailed information you can refer to a paper I
wrote:  
http://xxx.lanl.gov/pdf/physics/0603240

William




>On 22 Mar, 00:55, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Hi Rune,
>>
>> Although the system is dispersive, provided the phase and amplitude
reponse
>> of the system are linear over the bandwidth of the signal, the signal
will
>> propagate undistorted. This is satisfied in my system with a 50MHz
>> Modulation, 500MHz Carrier AM signal. I simply want to measure a
predicted
>> 3 degree phase shift of the Modulation. In order to do that I need to
>> extract the modulation and compare it to the modulation before the
>> propagation. I do not know if this can be done. This is why I am
asking.
>
>Why didn't you say that first time around?
>
>You asked the wrong question. If you want to measure
>dispersion, ask about how to measure dispersion, not
>about how to measure obscure quantities that are
>sensitive to most minute variations in initial
>conditions or environment parameters.
>
>In order to achieve what you want, the ideal set-up
>is to measure the input and output simultaneously
>and synchronously. If this is possible, estimate
>the cross spectrum of the twu signals, and estimate
>the phase.
>
>If it is not possible to measure input and output
>but you can use an array to measure the output, you
>can still come up with an estimate of the phase
>velocity.
>
>The one thing *not* to do , is to work directly
>with phase. But even if you want to do that, it
>is perfectly possible to use a linear phase FIR
>filter, and subtract the corresponding delay from
>the filtered data.
>
>But none of this matters until you have answered
>the real question: Why would you want to verify
>these predictions? What purpose could it possibly
>serve? If you don't trust the maths - why not
>verify it by measuring a quantity that is actually
>possible to measure with any accuracy, is robust
>to environmental variation, and can be processed?
>
>Rune
>

On 22 Mar, 11:55, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi Rune,
>
> The question you are asking is complicated but I will try to explain. I am
> trying to measure the speed of information transmission in the nearfield of
> a dipole source. This can be done by measuring the time delay of the
> envelope of an AM signal between two dipole antennas. Theoretical
> calculations show that the envelope should deviate about 3 degrees from
> light speed for a 50MHz modulated, 500MHz carrier signal.

"Deviate 3 degrees from light speed" ???

Again, one of the best ways to measure the effects of the
system is to measure both the input and the output and then
examine the cross correlation bewteen the two. This standard
approach will extract the relative changes through the system
while at the same time avoiding questions about absolute phase,
which depends on all kinds of details you couldn't possibly
track down anyway.

Get a copy of the book "Random Data" by Bendat and Piersol.

Rune

Rune Allnor wrote:
> On 22 Mar, 00:55, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
> wrote:
>> Hi Rune,
>>
>> Although the system is dispersive, provided the phase and amplitude reponse
>> of the system are linear over the bandwidth of the signal, the signal will
>> propagate undistorted. This is satisfied in my system with a 50MHz
>> Modulation, 500MHz Carrier AM signal. I simply want to measure a predicted
>> 3 degree phase shift of the Modulation. In order to do that I need to
>> extract the modulation and compare it to the modulation before the
>> propagation. I do not know if this can be done. This is why I am asking.
> 
> Why didn't you say that first time around?

Amen! This underscores the consultant's dilemma: give the client what he 
asks for, or what he needs.

I understand how we got here. Walker embarked on an inappropriate method 
  for getting a result and ran into difficulties. He asked about 
resolving those (unnecessary) difficulties, rather than about solving 
the real problem. It didn't help that a number of unwarranted 
assumptions blocked his understanding of the suggestions we made, but it 
didn't hurt much either because we were talking at cross purposes 
anyway. I feel rather silly for not having figured it out.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

Hi Rune,

The cross correlation technique does not seem to work very well with
sinusoidally modulated AM signals but it does seem to work with pulsed AM
signals. It appears that if the signal is not windowed properly one gets
leakage effects, whereas a pulsed AM signal is automatically windowed
properly. 

>"Deviate 3 degrees from light speed" ???

ph=wt=360*f*d/c where: ph=phase in deg, f=freq, c=speed light, r=wave
propagation distance. For a light speed propagating signal, at r=20cm, the
carrier will phase shift 120deg [360*500MHz*20cm/(3E8)] and the modulation
will phase shift 12 deg [360*50MHz*20cm/(3E8)]. I expect the modulation to
arrive 3 degrees earlier (i.e at 9 deg).

William

>On 22 Mar, 11:55, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Hi Rune,
>>
>> The question you are asking is complicated but I will try to explain. I
am
>> trying to measure the speed of information transmission in the nearfield
of
>> a dipole source. This can be done by measuring the time delay of the
>> envelope of an AM signal between two dipole antennas. Theoretical
>> calculations show that the envelope should deviate about 3 degrees from
>> light speed for a 50MHz modulated, 500MHz carrier signal.
>
>"Deviate 3 degrees from light speed" ???
>
>Again, one of the best ways to measure the effects of the
>system is to measure both the input and the output and then
>examine the cross correlation bewteen the two. This standard
>approach will extract the relative changes through the system
>while at the same time avoiding questions about absolute phase,
>which depends on all kinds of details you couldn't possibly
>track down anyway.
>
>Get a copy of the book "Random Data" by Bendat and Piersol.
>
>Rune
>

On 22 Mar, 00:48, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:

>=A0After a signal goes through a dispersive
> medium (such as optical fiber), it then goes through a phase
> conjugation device. =A0That reverses the effect such that passing
> through the same amount of fiber restores the original signal.
> That is, dispersive fiber+phase conjugation+dispersive fiber
> is, overall, not dispersive!

I remember reading some time in the mid / late '90s about a phase
conjugation tecnique used in a multipath scenario, in the context
of active sonars. Since phase conjugation in time domain amounts
to time reversal, these guys suggested to

1) Emit a known waveform into the water
2) Record the echo reflected off the target (which suffers from
   reverberation, multipath and what not)
3) Reverse the recorded signal and emit
4) Record the reflection from the time-reversed recording

I never understood what the purpose of all this might have
been.In 'standard mode' there are all kinds of problems
detecting the reflection of interest inbetween all the
multipaths and distortions. If you already know these
factors, you also know the reference time around which
to flip the signal.

If you are unable to untangle the recieved signal, you don't
know the key references, and effectively emit a random signal.
Even if the idea works, and you recieve something that is close
to the original pulse, you have no idea which part of the
emitted signal interacted with the target.

In the end, one have spent an awful lot of effort for no
gain at all.

Rune

WWalker wrote:
> Hi Rune,
> 
> The question you are asking is complicated but I will try to explain. I am
> trying to measure the speed of information transmission in the nearfield of
> a dipole source. This can be done by measuring the time delay of the
> envelope of an AM signal between two dipole antennas. Theoretical
> calculations show that the envelope should deviate about 3 degrees from
> light speed for a 50MHz modulated, 500MHz carrier signal. 
> 
> I would like to capture the transmitted and received signal on a 1GHz
> digital scope, extract the modulation envelopes, and measure the time
> delay. In order to measure the speed of information propagation, I need to
> also include the time it takes to demodulated the signal. Since the
> modulation light speed deviation is expected to only occur within a
> fraction (<1/10) of the carrier cycle, I need to come up with a
> demodulation technique that does not use a filter. This is because a filter
> takes more than a fraction of a carrier cycle to filter out the unwanted
> signals. If you want more detailed information you can refer to a paper I
> wrote:  
> http://xxx.lanl.gov/pdf/physics/0603240

You aren't making sense. "3 degrees from light speed" has less meaning 
than "3 degrees from south." Earlier, you wrote of group- and phase 
velocities that vary with distance. That is possible, but unusual. Is it 
really so?

It does not matter how much delay there may be in a filter, just so long 
as you know how much it is. It simplifies matters greatly if the delay 
is independent of frequency, and symmetric FIRs have that property.

Removing the imagined restrictions on what techniques can you use will 
make it much easier to fine a solution that you can implement woth your 
equipment.

jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

WWalker wrote:

   ...

> ph=wt=360*f*d/c where: ph=phase in deg, f=freq, c=speed light, r=wave
> propagation distance. For a light speed propagating signal, at r=20cm, the
> carrier will phase shift 120deg [360*500MHz*20cm/(3E8)] and the modulation
> will phase shift 12 deg [360*50MHz*20cm/(3E8)]. I expect the modulation to
> arrive 3 degrees earlier (i.e at 9 deg).

A misconception. The frequencies of the signals carrying the modulation 
are 450 and 550 MHz. Together with the carrier, they produce the beat 
pattern seen as an envelope.

   ...

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 22 Mar, 14:27, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi Rune,
>
> The cross correlation technique does not seem to work very well with
> sinusoidally modulated AM signals but it does seem to work with pulsed AM
> signals. It appears that if the signal is not windowed properly one gets
> leakage effects, whereas a pulsed AM signal is automatically windowed
> properly.
>
> >"Deviate 3 degrees from light speed" ???
>
> ph=wt=360*f*d/c where: ph=phase in deg, f=freq, c=speed light, r=wave
> propagation distance. For a light speed propagating signal, at r=20cm, the
> carrier will phase shift 120deg [360*500MHz*20cm/(3E8)] and the modulation
> will phase shift 12 deg [360*50MHz*20cm/(3E8)]. I expect the modulation to
> arrive 3 degrees earlier (i.e at 9 deg).

First of all - you are wrong.

The phase shift of the *demodulated* 50 MHz signal depends on
all kinds of details in the demodulating system, details you
have no way of knowing with sufficient accuracy.

Again: The only way you *might* come close, is to measure both
the input and output, run both through as similar processing
stages as possible (watch out for effects of variables in
the physical implementations!) and then run a cross correlation
analysis.

The spatial phase you talk about should be measured at 550 MHz,
which is the signal that actually propagates down the physical
channel.

And again: You haven't said anything about *why* you want to
do this. Relying on phase meaurements is very poor way of doing
anything. There is almost certainly a better way of doing
whatever it is you are up to.

Rune

Rune Allnor wrote:

   ...

> The spatial phase you talk about should be measured at 550 MHz,
> which is the signal that actually propagates down the physical
> channel.

 From what has been written, the signal is ordinary double-sideband AM. 
Make that 450 *and* 550 MHz, as I wrote at 10:04 (my time).

   ...

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 22 Mar, 16:14, Jerry Avins <j...@ieee.org> wrote:
> Rune Allnor wrote:
>
> =A0 =A0...
>
> > The spatial phase you talk about should be measured at 550 MHz,
> > which is the signal that actually propagates down the physical
> > channel.
>
> =A0From what has been written, the signal is ordinary double-sideband AM.

I didn't catch that SSB have been ruled out.

> Make that 450 *and* 550 MHz,

Agreed.

Rune

Hi, I agree with what you have said except I have my doubts about using
cross correlation.

>The phase shift of the *demodulated* 50 MHz signal depends on
>all kinds of details in the demodulating system, details you
>have no way of knowing with sufficient accuracy.
>
>Again: The only way you *might* come close, is to measure both
>the input and output, run both through as similar processing
>stages as possible (watch out for effects of variables in
>the physical implementations!) and then run a cross correlation
>analysis.

I do not see how to use the cross correlation to get the modulation delay.
When I tried to cross correlate the input AM signal with the output AM
signal (both sinusoidally modulated) I got a modulated triangular signal,
where the triangle peak should be the Time Span of the windowed data plus
the modulation time delay. Unfortunatly the peak of the triangle is not
directly available. One has to extract the envelope of the modulated
correlation signal to be able to determine the triangle peak, which is
similar to what I have been trying to do with other techniques.     


>And again: You haven't said anything about *why* you want to
>do this. Relying on phase meaurements is very poor way of doing
>anything. There is almost certainly a better way of doing
>whatever it is you are up to.
>

I want to show that information propagates faster than light in the
nearfield of a dipole source. Network analyser measurments between dipole
antennas show that the phase is nonlinear in the nearfield and only linear
in the farfield. Analysis of the phase vs freq curve shows that the group
speed is faster than light in the nearfield. Refer to p. 25-26 of my
paper:
http://xxx.lanl.gov/pdf/physics/0603240
 

William

WWalker wrote:
> Hi, I agree with what you have said except I have my doubts about using
> cross correlation.
> 
>> The phase shift of the *demodulated* 50 MHz signal depends on
>> all kinds of details in the demodulating system, details you
>> have no way of knowing with sufficient accuracy.
>>
>> Again: The only way you *might* come close, is to measure both
>> the input and output, run both through as similar processing
>> stages as possible (watch out for effects of variables in
>> the physical implementations!) and then run a cross correlation
>> analysis.
> 
> I do not see how to use the cross correlation to get the modulation delay.
> When I tried to cross correlate the input AM signal with the output AM
> signal (both sinusoidally modulated) I got a modulated triangular signal,
> where the triangle peak should be the Time Span of the windowed data plus
> the modulation time delay. Unfortunatly the peak of the triangle is not
> directly available. One has to extract the envelope of the modulated
> correlation signal to be able to determine the triangle peak, which is
> similar to what I have been trying to do with other techniques.     
> 
> 
>> And again: You haven't said anything about *why* you want to
>> do this. Relying on phase meaurements is very poor way of doing
>> anything. There is almost certainly a better way of doing
>> whatever it is you are up to.
>>
> 
> I want to show that information propagates faster than light in the
> nearfield of a dipole source. Network analyser measurments between dipole
> antennas show that the phase is nonlinear in the nearfield and only linear
> in the farfield. Analysis of the phase vs freq curve shows that the group
> speed is faster than light in the nearfield. Refer to p. 25-26 of my
> paper:
> http://xxx.lanl.gov/pdf/physics/0603240

I think I have sad news for you. If faster-than-light information 
propagation were implemented in a general way, the future could be 
foretold. While we cannot foretell the future, we can predict it with 
more or less success. In particular, band-limited signals can be 
predicted quite accurately. That makes it possible to create scenarios 
that appear to foretell. As soon as the restriction on bandwidth is 
lifted, these apparent paradoxes resolve themselves. I believe it was 
Andor Bariska who posted striking demonstration of this.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 22 Mar, 16:30, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi, I agree with what you have said except I have my doubts about using
> cross correlation.
>
> >The phase shift of the *demodulated* 50 MHz signal depends on
> >all kinds of details in the demodulating system, details you
> >have no way of knowing with sufficient accuracy.
>
> >Again: The only way you *might* come close, is to measure both
> >the input and output, run both through as similar processing
> >stages as possible (watch out for effects of variables in
> >the physical implementations!) and then run a cross correlation
> >analysis.
>
> I do not see how to use the cross correlation to get the modulation delay=
..
> When I tried to cross correlate the input AM signal with the output AM
> signal (both sinusoidally modulated) I got a modulated triangular signal,
> where the triangle peak should be the Time Span of the windowed data plus
> the modulation time delay. Unfortunatly the peak of the triangle is not
> directly available. One has to extract the envelope of the modulated
> correlation signal to be able to determine the triangle peak, which is
> similar to what I have been trying to do with other techniques. =A0 =A0

Cross correlation gets you the phase delay you want.
All you need, is to understand what you are up to, how
the methods work, the error sources and how to atually
do the analysis.

Get the Bendat and Piersol book.

> >And again: You haven't said anything about *why* you want to
> >do this. Relying on phase meaurements is very poor way of doing
> >anything. There is almost certainly a better way of doing
> >whatever it is you are up to.
>
> I want to show that information propagates faster than light in the
> nearfield of a dipole source. Network analyser measurments between dipole
> antennas show that the phase is nonlinear in the nearfield and only linea=
r
> in the farfield. Analysis of the phase vs freq curve shows that the group
> speed is faster than light in the nearfield. Refer to p. 25-26 of my
> paper:http://xxx.lanl.gov/pdf/physics/0603240

Ouch... well, you claim affiliations with NTNU, so what
would one expect... you wouldn't happen to be aware of the
"Hjernevask" reports by Harald Eia, who is aired on NRK1
these days? This projects fits straight in there.

You need to be *extremely* cautious about what you are up to.
The stuff you are measuring is interference effects between
spherical waves, *not* the propagation of energy. It is very
easy to obtain infinite phase speeds in the case of plane waves:
A plane wave, in the ocean, that impinges perpendiculary to a
beach will exhibit an infinite phase speed along the beach.
The apparent wavelength is infinitely long, so the apparent
wave speed (phase velosity) is infinite. But the velocity
of information down the lenght of the beach is 0.

Whatever it is you *think* you measure, similar effects
are in play. Check out the writings of Johan Leander in
the Journal of the Acoustical Society of America, in 1995
or 1996.

Rune

Rune Allnor <allnor@tele.ntnu.no> wrote:
> On 22 Mar, 00:48, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
 
>>?After a signal goes through a dispersive
>> medium (such as optical fiber), it then goes through a phase
>> conjugation device. ?That reverses the effect such that passing
>> through the same amount of fiber restores the original signal.
>> That is, dispersive fiber+phase conjugation+dispersive fiber
>> is, overall, not dispersive!
 
> I remember reading some time in the mid / late '90s about a phase
> conjugation tecnique used in a multipath scenario, in the context
> of active sonars. Since phase conjugation in time domain amounts
> to time reversal, these guys suggested to

I understand phase conjugation for optical systems better, but...
 
> 1) Emit a known waveform into the water
> 2) Record the echo reflected off the target (which suffers from
>   reverberation, multipath and what not)
> 3) Reverse the recorded signal and emit
> 4) Record the reflection from the time-reversed recording

The main thing this depends on is that conditions don't change
(too much) between the two emission times.  For time reversal,
you can't start sending the time reversed signal until all of
the first one is received.  For optics, that time is related
to the size of the phase conjugation device.
 
> I never understood what the purpose of all this might have
> been.In 'standard mode' there are all kinds of problems
> detecting the reflection of interest inbetween all the
> multipaths and distortions. If you already know these
> factors, you also know the reference time around which
> to flip the signal.

I will guess that temperature gradients are part of the cause
of dispersion.  Presumably they change with time as currents move
the water around.  
 
> If you are unable to untangle the recieved signal, you don't
> know the key references, and effectively emit a random signal.
> Even if the idea works, and you recieve something that is close
> to the original pulse, you have no idea which part of the
> emitted signal interacted with the target.

Well, that problem is always there.  
 
> In the end, one have spent an awful lot of effort for no
> gain at all.

-- glen

Hi Rune,

Although the cross correlation method could perhaps be used to measure the
time delay of the modulation, this still does not help me. I want to
extract the modulation from the signal and show that it can be done in less
than a fraction (<1/10) of a carrier cycle. Dividing by the carrier does
this but the required SNR is too high to be practical. Transmitting
Q=A(t)Sin(Wct)and I=A(t)Cos(Wct)through the antennas and demodulating using
A(t)=Sqrt[I^2 + Q^2] also works. But I was hoping to find a method to
extract the modulation using only one signal, such as: A(t)Sin(Wct)

Any ideas?

William

>On 22 Mar, 16:30, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Hi, I agree with what you have said except I have my doubts about using
>> cross correlation.
>>
>> >The phase shift of the *demodulated* 50 MHz signal depends on
>> >all kinds of details in the demodulating system, details you
>> >have no way of knowing with sufficient accuracy.
>>
>> >Again: The only way you *might* come close, is to measure both
>> >the input and output, run both through as similar processing
>> >stages as possible (watch out for effects of variables in
>> >the physical implementations!) and then run a cross correlation
>> >analysis.
>>
>> I do not see how to use the cross correlation to get the modulation
delay=
>.
>> When I tried to cross correlate the input AM signal with the output AM
>> signal (both sinusoidally modulated) I got a modulated triangular
signal,
>> where the triangle peak should be the Time Span of the windowed data
plus
>> the modulation time delay. Unfortunatly the peak of the triangle is not
>> directly available. One has to extract the envelope of the modulated
>> correlation signal to be able to determine the triangle peak, which is
>> similar to what I have been trying to do with other techniques. =A0 =A0
>
>Cross correlation gets you the phase delay you want.
>All you need, is to understand what you are up to, how
>the methods work, the error sources and how to atually
>do the analysis.
>
>Get the Bendat and Piersol book.
>
>> >And again: You haven't said anything about *why* you want to
>> >do this. Relying on phase meaurements is very poor way of doing
>> >anything. There is almost certainly a better way of doing
>> >whatever it is you are up to.
>>
>> I want to show that information propagates faster than light in the
>> nearfield of a dipole source. Network analyser measurments between
dipole
>> antennas show that the phase is nonlinear in the nearfield and only
linea=
>r
>> in the farfield. Analysis of the phase vs freq curve shows that the
group
>> speed is faster than light in the nearfield. Refer to p. 25-26 of my
>> paper:http://xxx.lanl.gov/pdf/physics/0603240
>
>Ouch... well, you claim affiliations with NTNU, so what
>would one expect... you wouldn't happen to be aware of the
>"Hjernevask" reports by Harald Eia, who is aired on NRK1
>these days? This projects fits straight in there.
>
>You need to be *extremely* cautious about what you are up to.
>The stuff you are measuring is interference effects between
>spherical waves, *not* the propagation of energy. It is very
>easy to obtain infinite phase speeds in the case of plane waves:
>A plane wave, in the ocean, that impinges perpendiculary to a
>beach will exhibit an infinite phase speed along the beach.
>The apparent wavelength is infinitely long, so the apparent
>wave speed (phase velosity) is infinite. But the velocity
>of information down the lenght of the beach is 0.
>
>Whatever it is you *think* you measure, similar effects
>are in play. Check out the writings of Johan Leander in
>the Journal of the Acoustical Society of America, in 1995
>or 1996.
>
>Rune
>

Hi Rune,

What ever the the reason for this phenomina, given the known and excepted
transfer function of a dipole source, It should be possible to transmit
information faster than light by transmitting an AM signal in the nearfield
and decoding the modulation. Simmulations clearly show that the envelope of
an AM signal will arrive faster than light and undistorted in the
nearfield. What is needed now is to find a way to decode the modulation
within a fraction of (<1/10) a carrier cycle. 

>You need to be *extremely* cautious about what you are up to.
>The stuff you are measuring is interference effects between
>spherical waves, *not* the propagation of energy. It is very
>easy to obtain infinite phase speeds in the case of plane waves:
>A plane wave, in the ocean, that impinges perpendiculary to a
>beach will exhibit an infinite phase speed along the beach.
>The apparent wavelength is infinitely long, so the apparent
>wave speed (phase velosity) is infinite. But the velocity
>of information down the lenght of the beach is 0.
>
>Whatever it is you *think* you measure, similar effects
>are in play. Check out the writings of Johan Leander in
>the Journal of the Acoustical Society of America, in 1995
>or 1996.
>
>Rune
>

WWalker wrote:
> Hi Rune,
> 
> Although the cross correlation method could perhaps be used to measure the
> time delay of the modulation, this still does not help me. I want to
> extract the modulation from the signal and show that it can be done in less
> than a fraction (<1/10) of a carrier cycle. Dividing by the carrier does
> this but the required SNR is too high to be practical. Transmitting
> Q=A(t)Sin(Wct)and I=A(t)Cos(Wct)through the antennas and demodulating using
> A(t)=Sqrt[I^2 + Q^2] also works. But I was hoping to find a method to
> extract the modulation using only one signal, such as: A(t)Sin(Wct)
> 
> Any ideas?

You just don't pay attention to what's being said to you. I can't help 
you, so I'll stop trying.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi Rune,
>
> What ever the the reason for this phenomina, given the known and excepted
> transfer function of a dipole source, It should be possible to transmit
> information faster than light by transmitting an AM signal in the nearfield
> and decoding the modulation. Simmulations clearly show that the envelope of
> an AM signal will arrive faster than light and undistorted in the
> nearfield. What is needed now is to find a way to decode the modulation
> within a fraction of (<1/10) a carrier cycle.

Wrong.

Your simulations use fixed-parameter sinusoidals and have
as such nothing to do with information, only steady states.
Everything is known all the time; there is nothing new to
be learned from observing the wave field. Hence, no
information is transmitted.

If you want to transmit *information*, you need to change
something in the wavefield: The amplitude, the frequency
or the phase. Something that is not known, that the reciever
has to lock on to, detect and quantify. It is this *transient*
change to an *unknown* state that carries the information down
range between transmitter and reciever.

I can guarantee that you will find that the transients
propagate down range with a speed exactly equal to c.

Rune

Rune Allnor <allnor@tele.ntnu.no> writes:
> [...]
> I can guarantee that you will find that the transients
> propagate down range with a speed exactly equal to c.

<chuckle>
-- 
Randy Yates                      % "Midnight, on the water... 
Digital Signal Labs              %  I saw...  the ocean's daughter." 
mailto://yates@ieee.org          % 'Can't Get It Out Of My Head' 
http://www.digitalsignallabs.com % *El Dorado*, Electric Light Orchestra

Rune Allnor wrote:
> On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
> wrote:
>> Hi Rune,
>>
>> What ever the the reason for this phenomina, given the known and excepted
>> transfer function of a dipole source, It should be possible to transmit
>> information faster than light by transmitting an AM signal in the nearfield
>> and decoding the modulation. Simmulations clearly show that the envelope of
>> an AM signal will arrive faster than light and undistorted in the
>> nearfield. What is needed now is to find a way to decode the modulation
>> within a fraction of (<1/10) a carrier cycle.
> 
> Wrong.
> 
> Your simulations use fixed-parameter sinusoidals and have
> as such nothing to do with information, only steady states.
> Everything is known all the time; there is nothing new to
> be learned from observing the wave field. Hence, no
> information is transmitted.
> 
> If you want to transmit *information*, you need to change
> something in the wavefield: The amplitude, the frequency
> or the phase. Something that is not known, that the reciever
> has to lock on to, detect and quantify. It is this *transient*
> change to an *unknown* state that carries the information down
> range between transmitter and reciever.
> 
> I can guarantee that you will find that the transients
> propagate down range with a speed exactly equal to c.

Or perhaps slower in the near field -- certainly waves in a waveguide 
generally have a phase speed that's faster than c, but a group velocity 
that's slower.

I wouldn't know if near field really is slower without doing the math, 
and I'd have to go back to school for a year or two to do that!

Information encoded on entangled photons may or may not travel faster 
than light, but if they did so reliably and easily I would expect some 
commercial exploitation by now.

-- 
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Rune Allnor wrote:
> On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
> wrote:
>> Hi Rune,
>>
>> What ever the the reason for this phenomina, given the known and excepted
>> transfer function of a dipole source, It should be possible to transmit
>> information faster than light by transmitting an AM signal in the nearfield
>> and decoding the modulation. Simmulations clearly show that the envelope of
>> an AM signal will arrive faster than light and undistorted in the
>> nearfield. What is needed now is to find a way to decode the modulation
>> within a fraction of (<1/10) a carrier cycle.
> 
> Wrong.
> 
> Your simulations use fixed-parameter sinusoidals and have
> as such nothing to do with information, only steady states.
> Everything is known all the time; there is nothing new to
> be learned from observing the wave field. Hence, no
> information is transmitted.
> 
> If you want to transmit *information*, you need to change
> something in the wavefield: The amplitude, the frequency
> or the phase. Something that is not known, that the reciever
> has to lock on to, detect and quantify. It is this *transient*
> change to an *unknown* state that carries the information down
> range between transmitter and reciever.
> 
> I can guarantee that you will find that the transients
> propagate down range with a speed exactly equal to c.

Not necessarily that fast. Note that in waveguides, the product of phase 
ans group velocities is c^2. At cutoff, the group velocity drops to zero 
and the phase velocity becomes infinite. The energy travels transversely 
(cross the axis of the guide) giving infinite phase velocity like a wave 
straight onto a beach, so there is no energy traveling along the axis, 
making the group velocity zero.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

I dissagree. 

Simulation results show that if you add two signals with different
frequencies and differnt amplitudes, the resultant signal changes in a
random way as far as a detector is concerned. If the signal is modulated
with a carrier and transmitted by a dipole antenna to another dipole
antenna in the nearfield, the envelope of the received signal arrives
undistorted, faster than light. This is because for a narrowband AM signal,
the dispersion curve (phase and amplitude) is linear over the bandwidth of
the signal. Provided the SNR is high enough, the random modulation
information can then be decoded by dividing by the carrier. Comparing the
transmitted modulation to the received modulation clearly shows that the
modulation propagates undistorted, faster than light in the nearfield. 

But if a pulse is transmitted in the nearfield the pulse will distort
because the dispersion curve (phase and amplitude) is not linear over the
bandwidth of the signal, so group speed has no meaning in the nearfield.
But in the farfield, the pulse will realign and propagate without
distortion at the speed of light, so the pulse group speed only has meaning
in the farfield.

William



>On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Hi Rune,
>>
>> What ever the the reason for this phenomina, given the known and
excepted
>> transfer function of a dipole source, It should be possible to transmit
>> information faster than light by transmitting an AM signal in the
nearfield
>> and decoding the modulation. Simmulations clearly show that the envelope
of
>> an AM signal will arrive faster than light and undistorted in the
>> nearfield. What is needed now is to find a way to decode the modulation
>> within a fraction of (<1/10) a carrier cycle.
>
>Wrong.
>
>Your simulations use fixed-parameter sinusoidals and have
>as such nothing to do with information, only steady states.
>Everything is known all the time; there is nothing new to
>be learned from observing the wave field. Hence, no
>information is transmitted.
>
>If you want to transmit *information*, you need to change
>something in the wavefield: The amplitude, the frequency
>or the phase. Something that is not known, that the reciever
>has to lock on to, detect and quantify. It is this *transient*
>change to an *unknown* state that carries the information down
>range between transmitter and reciever.
>
>I can guarantee that you will find that the transients
>propagate down range with a speed exactly equal to c.
>
>Rune
>

Randy Yates wrote:

> Rune Allnor <allnor@tele.ntnu.no> writes:
> 
>>[...]
>>I can guarantee that you will find that the transients
>>propagate down range with a speed exactly equal to c.
> 
> 
> <chuckle>

It looks like there is more and more of them every day.
Scarry.

VLV

On 3/22/2010 5:12 PM, WWalker wrote:
> I dissagree.
>
> Simulation results show that if you add two signals with different
> frequencies and differnt amplitudes, the resultant signal changes in a
> random way as far as a detector is concerned. If the signal is modulated
> with a carrier and transmitted by a dipole antenna to another dipole
> antenna in the nearfield, the envelope of the received signal arrives
> undistorted, faster than light. This is because for a narrowband AM signal,
> the dispersion curve (phase and amplitude) is linear over the bandwidth of
> the signal. Provided the SNR is high enough, the random modulation
> information can then be decoded by dividing by the carrier. Comparing the
> transmitted modulation to the received modulation clearly shows that the
> modulation propagates undistorted, faster than light in the nearfield.
>
> But if a pulse is transmitted in the nearfield the pulse will distort
> because the dispersion curve (phase and amplitude) is not linear over the
> bandwidth of the signal, so group speed has no meaning in the nearfield.
> But in the farfield, the pulse will realign and propagate without
> distortion at the speed of light, so the pulse group speed only has meaning
> in the farfield.
>
> William

Mixing top and bottom posting is very bad form and makes your responses 
difficult to read, or at least very difficult to sort out the logic 
train you're responding to.

So what carries the information faster than light?  Clearly it can't be 
an EM photon, since they're inherently limited to c.   If it's not via 
EM photons, how does the energy get from the transmit to the receive 
antenna?




>
>> On 22 Mar, 22:43, "WWalker"<william.walker@n_o_s_p_a_m.imtek.de>
>> wrote:
>>> Hi Rune,
>>>
>>> What ever the the reason for this phenomina, given the known and
> excepted
>>> transfer function of a dipole source, It should be possible to transmit
>>> information faster than light by transmitting an AM signal in the
> nearfield
>>> and decoding the modulation. Simmulations clearly show that the envelope
> of
>>> an AM signal will arrive faster than light and undistorted in the
>>> nearfield. What is needed now is to find a way to decode the modulation
>>> within a fraction of (<1/10) a carrier cycle.
>>
>> Wrong.
>>
>> Your simulations use fixed-parameter sinusoidals and have
>> as such nothing to do with information, only steady states.
>> Everything is known all the time; there is nothing new to
>> be learned from observing the wave field. Hence, no
>> information is transmitted.
>>
>> If you want to transmit *information*, you need to change
>> something in the wavefield: The amplitude, the frequency
>> or the phase. Something that is not known, that the reciever
>> has to lock on to, detect and quantify. It is this *transient*
>> change to an *unknown* state that carries the information down
>> range between transmitter and reciever.
>>
>> I can guarantee that you will find that the transients
>> propagate down range with a speed exactly equal to c.
>>
>> Rune
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

On 23 Mar, 01:12, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> I dissagree.
>
> Simulation results show that if you add two signals with different
> frequencies and differnt amplitudes, the resultant signal changes in a
> random way as far as a detector is concerned.

That's the interference. In a steady-state condition.

Interference is hard to quantify because it is chaotic: Make
the slightest change in any of the initial conditions or
environmental parameters, and it causes a total chance of the
resulting interfernce pattern.

> If the signal is modulated
> with a carrier and transmitted by a dipole antenna to another dipole
> antenna in the nearfield, the envelope of the received signal arrives
> undistorted, faster than light.

No, it doesn't. The amateur might have a look at the interference
and get such ideas, but the professional will be aware of
observations of the wave field at oblique angles from the
propagation.

This is a simple excercise, that can even be simulated:

Start out with a 2D plane wave propagating in the x direction:

s(t,x,y) = sin( 2pi f(t - x/c) )

Then observe it along a line through (0,0) that intersects the
wavefield at an angle with the x axis, phi. If phi = 0, you
will see an apparent wavelength, lambda', along the line that
equals the free field wavelength lambda = c / f.

Change the angle of the observation line, and find that
the apparent wavelength equals

lambda' = lambda / cos(phi)

Run a simulation of how the observation changes with time,
and find that the *apparent* speed c' of the wave along the
observation line equals

c' = lambda' f = lambda f / cos (phi) = c / cos(phi).

It's a ridiculously simple trap, but it seems you
have fallen into it.

Rune

On 23 Mar, 02:16, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
> Randy Yates wrote:
> > Rune Allnor <all...@tele.ntnu.no> writes:
>
> >>[...]
> >>I can guarantee that you will find that the transients
> >>propagate down range with a speed exactly equal to c.
>
> > <chuckle>
>
> It looks like there is more and more of them every day.
> Scarry.

I don't know if you have looked at the paper he has referred
to a couple of times. He claims that he at some time was
affiliated with NTNU. I am not at all surprised - this kind
of stuff is just what I would expect from that place.

Once upon a time I asked what the procedure is to hand back
my PhD diplomas etc, as I didn't want more affiliations with
them than absolutely necessary. Cut as many ties as possible.

It turned out there were no such procedures. So one needs to
be acutely cautious about whose company one seeks - their stain
might last a lifetime.

Rune

>On 23 Mar, 02:16, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
>> Randy Yates wrote:
>> > Rune Allnor <all...@tele.ntnu.no> writes:
>>
>> >>[...]
>> >>I can guarantee that you will find that the transients
>> >>propagate down range with a speed exactly equal to c.
>>
>> > <chuckle>
>>
>> It looks like there is more and more of them every day.
>> Scarry.
>
>I don't know if you have looked at the paper he has referred
>to a couple of times. He claims that he at some time was
>affiliated with NTNU. I am not at all surprised - this kind
>of stuff is just what I would expect from that place.
>
>Once upon a time I asked what the procedure is to hand back
>my PhD diplomas etc, as I didn't want more affiliations with
>them than absolutely necessary. Cut as many ties as possible.
>
>It turned out there were no such procedures. So one needs to
>be acutely cautious about whose company one seeks - their stain
>might last a lifetime.

You're being too negative. I think he's on to something, and will produce
the ideal advanced communications system to showcase my new infinite gain
bandwidth amplifier.

Steve

Rune,

Your arguments do not apply. First of all the fields in the nearfield are
not plane waves and secondly, the superluminal effect is observed when the
antennas are pointed directly at each other (phi=0).

William


>On 23 Mar, 01:12, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> I dissagree.
>>
>> Simulation results show that if you add two signals with different
>> frequencies and differnt amplitudes, the resultant signal changes in a
>> random way as far as a detector is concerned.
>
>That's the interference. In a steady-state condition.
>
>Interference is hard to quantify because it is chaotic: Make
>the slightest change in any of the initial conditions or
>environmental parameters, and it causes a total chance of the
>resulting interfernce pattern.
>
>> If the signal is modulated
>> with a carrier and transmitted by a dipole antenna to another dipole
>> antenna in the nearfield, the envelope of the received signal arrives
>> undistorted, faster than light.
>
>No, it doesn't. The amateur might have a look at the interference
>and get such ideas, but the professional will be aware of
>observations of the wave field at oblique angles from the
>propagation.
>
>This is a simple excercise, that can even be simulated:
>
>Start out with a 2D plane wave propagating in the x direction:
>
>s(t,x,y) = sin( 2pi f(t - x/c) )
>
>Then observe it along a line through (0,0) that intersects the
>wavefield at an angle with the x axis, phi. If phi = 0, you
>will see an apparent wavelength, lambda', along the line that
>equals the free field wavelength lambda = c / f.
>
>Change the angle of the observation line, and find that
>the apparent wavelength equals
>
>lambda' = lambda / cos(phi)
>
>Run a simulation of how the observation changes with time,
>and find that the *apparent* speed c' of the wave along the
>observation line equals
>
>c' = lambda' f = lambda f / cos (phi) = c / cos(phi).
>
>It's a ridiculously simple trap, but it seems you
>have fallen into it.
>
>Rune
>

Rune,

Critisisms about where the research was done are irrelevant to the
discussion and pointless. Lets discuss the ideas. They are the only thing
that matter in this discussion.  

William

>On 23 Mar, 02:16, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
>> Randy Yates wrote:
>> > Rune Allnor <all...@tele.ntnu.no> writes:
>>
>> >>[...]
>> >>I can guarantee that you will find that the transients
>> >>propagate down range with a speed exactly equal to c.
>>
>> > <chuckle>
>>
>> It looks like there is more and more of them every day.
>> Scarry.
>
>I don't know if you have looked at the paper he has referred
>to a couple of times. He claims that he at some time was
>affiliated with NTNU. I am not at all surprised - this kind
>of stuff is just what I would expect from that place.
>
>Once upon a time I asked what the procedure is to hand back
>my PhD diplomas etc, as I didn't want more affiliations with
>them than absolutely necessary. Cut as many ties as possible.
>
>It turned out there were no such procedures. So one needs to
>be acutely cautious about whose company one seeks - their stain
>might last a lifetime.
>
>Rune
>

Hi Eric,

Sorry for the confusion. I will try to stick to top posting.

Regarding your question about what carries the information faster than
light, I can not say for sure, but I suspect it is the virtual photon. The
only thing I can say for sure is that the envelope of a narrow band
modulated signal propagates undistortted, faster than light in the
nearfield of a dipole source. If this is true then Relativity theory will
need to be reevaluated. For more information, refer to my other paper:
http://xxx.lanl.gov/pdf/physics/0702166

William


>On 3/22/2010 5:12 PM, WWalker wrote:
>> I dissagree.
>>
>> Simulation results show that if you add two signals with different
>> frequencies and differnt amplitudes, the resultant signal changes in a
>> random way as far as a detector is concerned. If the signal is
modulated
>> with a carrier and transmitted by a dipole antenna to another dipole
>> antenna in the nearfield, the envelope of the received signal arrives
>> undistorted, faster than light. This is because for a narrowband AM
signal,
>> the dispersion curve (phase and amplitude) is linear over the bandwidth
of
>> the signal. Provided the SNR is high enough, the random modulation
>> information can then be decoded by dividing by the carrier. Comparing
the
>> transmitted modulation to the received modulation clearly shows that
the
>> modulation propagates undistorted, faster than light in the nearfield.
>>
>> But if a pulse is transmitted in the nearfield the pulse will distort
>> because the dispersion curve (phase and amplitude) is not linear over
the
>> bandwidth of the signal, so group speed has no meaning in the
nearfield.
>> But in the farfield, the pulse will realign and propagate without
>> distortion at the speed of light, so the pulse group speed only has
meaning
>> in the farfield.
>>
>> William
>
>Mixing top and bottom posting is very bad form and makes your responses 
>difficult to read, or at least very difficult to sort out the logic 
>train you're responding to.
>
>So what carries the information faster than light?  Clearly it can't be 
>an EM photon, since they're inherently limited to c.   If it's not via 
>EM photons, how does the energy get from the transmit to the receive 
>antenna?
>
>
>
>
>>
>>> On 22 Mar, 22:43, "WWalker"<william.walker@n_o_s_p_a_m.imtek.de>
>>> wrote:
>>>> Hi Rune,
>>>>
>>>> What ever the the reason for this phenomina, given the known and
>> excepted
>>>> transfer function of a dipole source, It should be possible to
transmit
>>>> information faster than light by transmitting an AM signal in the
>> nearfield
>>>> and decoding the modulation. Simmulations clearly show that the
envelope
>> of
>>>> an AM signal will arrive faster than light and undistorted in the
>>>> nearfield. What is needed now is to find a way to decode the
modulation
>>>> within a fraction of (<1/10) a carrier cycle.
>>>
>>> Wrong.
>>>
>>> Your simulations use fixed-parameter sinusoidals and have
>>> as such nothing to do with information, only steady states.
>>> Everything is known all the time; there is nothing new to
>>> be learned from observing the wave field. Hence, no
>>> information is transmitted.
>>>
>>> If you want to transmit *information*, you need to change
>>> something in the wavefield: The amplitude, the frequency
>>> or the phase. Something that is not known, that the reciever
>>> has to lock on to, detect and quantify. It is this *transient*
>>> change to an *unknown* state that carries the information down
>>> range between transmitter and reciever.
>>>
>>> I can guarantee that you will find that the transients
>>> propagate down range with a speed exactly equal to c.
>>>
>>> Rune
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 23 Mar, 11:53, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> Critisisms about where the research was done are irrelevant to the
> discussion and pointless.

It is relevant in two respects:

- Once you claim affiliations with an institution, you
  also claim to represent the institution.
- You as student is subjected to the standards of the
  institution where you do your work. What you have
  presented in this thread is totally consistent with
  the standards of NTNU.

> Lets discuss the ideas. They are the only thing
> that matter in this discussion. =A0

There are no ideas. Only misconceptions at a level
where you ought not to have been admitted to a technical
university at all (except, of course, for NTNU) and
sloppy investigations where you consistently and, for
all I know, deliberately disregard the actual explanations
of what you observe.

Rune

Rune,

No one is interested in your emotional rantings. If you have something
intelligent to say about the system in discussion then lets talk. But
support your ideas with logic. I have given you logical arguments
supporting the superluminal conclusion, which ones can you prove are wrong.
If you can't then be quiet. Emotional rantings only make you look foolish.

William 




>On 23 Mar, 11:53, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Rune,
>>
>> Critisisms about where the research was done are irrelevant to the
>> discussion and pointless.
>
>It is relevant in two respects:
>
>- Once you claim affiliations with an institution, you
>  also claim to represent the institution.
>- You as student is subjected to the standards of the
>  institution where you do your work. What you have
>  presented in this thread is totally consistent with
>  the standards of NTNU.
>
>> Lets discuss the ideas. They are the only thing
>> that matter in this discussion. =A0
>
>There are no ideas. Only misconceptions at a level
>where you ought not to have been admitted to a technical
>university at all (except, of course, for NTNU) and
>sloppy investigations where you consistently and, for
>all I know, deliberately disregard the actual explanations
>of what you observe.
>
>Rune
>

On 23 Mar, 13:40, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> No one is interested in your emotional rantings. If you have something
> intelligent to say about the system in discussion then lets talk. But
> support your ideas with logic. I have given you logical arguments
> supporting the superluminal conclusion, which ones can you prove are wrong.

What you have showed in this thread, is that you

1) Consistently fail to use the simplest terminology
   wrt to wave propagation
2) Do not have the faintest clue about data analysis
3) Do not know or understand the implications of
   the speed of light as an absolute limit in physics
4) Do not know or understand the basics of dipole
   antennae
5) Do not know or understand how to set up a simulation
6) Do not know or understand how to analyze the data
   from said simulation
7) Do not know or undesrtand how to criticise the results
   of said simulation
8) Do not know or understand the basics of information
   theory

....and those are just the ones I remember off the top
of my head.

As for fools and proofs - well, it's more than a century since
Einstein presented his relativity theory, where the speed of
light is established as a fundamental limit in physics. When I
say that you ought not to have been admitted as a student
to a technical university, it's because anyone who passes a
high-school level class in physics should know this, and
at least stop and think through their own ideas and arguments
once one starts talking about exceeding the speed of light.

You have failed blatantly on that point. So if anyone her is
a fool, it would be you.

Apart from that, it is up to the person that makes the
extraordinary claim to argue in his own support. *If* you
were to be right, it would mean that anything and everything
that is based on Einstein's relativity theory - nuclear
weapons and powerplants, cosmogology, the stuff they do at
CERN - would turn out to be wrong.

By all means - it's up to you to make that claim. Just be
prepared to be asked thay *you* prove that your are right.
It would take a lot more than a mere simulation you don't
know how to do, of stuff you don't know, to convince anyone
outside NTNU.

Rune

>Rune,
>
>No one is interested in your emotional rantings. If you have something
>intelligent to say about the system in discussion then lets talk. But
>support your ideas with logic. I have given you logical arguments
>supporting the superluminal conclusion, which ones can you prove are
wrong.
>If you can't then be quiet. Emotional rantings only make you look
foolish.

You are the one looking foolish up to now. If you want to claim you have
perpetual motion, you need an *exceedingly* powerful argument before anyone
will stop laughing. If you want to claim you have infinite gain bandwidth
product you need an *exceedingly* powerful argument before anyone will stop
laughing. If you want to claim you can carry information faster than light
you need to a) prove that people like Shannon and others were wrong, and
that information and energy are not interchangeable terms, or b) that you
have found a way to carry energy faster than light. So far, all you've done
it describe a variety of things that look like the phantom fast moving
phase effects we all meet quite regularly. When amplitude or phase
manipulation is really carrying information, its because those things are
directly related to real energy manipulation.

Steve

You still have not come up with any intelligent comments refuting my
arguments. Your resort to insults does not help. 

>On 23 Mar, 13:40, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Rune,
>>
>> No one is interested in your emotional rantings. If you have something
>> intelligent to say about the system in discussion then lets talk. But
>> support your ideas with logic. I have given you logical arguments
>> supporting the superluminal conclusion, which ones can you prove are
wrong.
>
>What you have showed in this thread, is that you
>
>1) Consistently fail to use the simplest terminology
>   wrt to wave propagation
>2) Do not have the faintest clue about data analysis
>3) Do not know or understand the implications of
>   the speed of light as an absolute limit in physics
>4) Do not know or understand the basics of dipole
>   antennae
>5) Do not know or understand how to set up a simulation
>6) Do not know or understand how to analyze the data
>   from said simulation
>7) Do not know or undesrtand how to criticise the results
>   of said simulation
>8) Do not know or understand the basics of information
>   theory
>
>...and those are just the ones I remember off the top
>of my head.
>
>As for fools and proofs - well, it's more than a century since
>Einstein presented his relativity theory, where the speed of
>light is established as a fundamental limit in physics. When I
>say that you ought not to have been admitted as a student
>to a technical university, it's because anyone who passes a
>high-school level class in physics should know this, and
>at least stop and think through their own ideas and arguments
>once one starts talking about exceeding the speed of light.
>
>You have failed blatantly on that point. So if anyone her is
>a fool, it would be you.
>
>Apart from that, it is up to the person that makes the
>extraordinary claim to argue in his own support. *If* you
>were to be right, it would mean that anything and everything
>that is based on Einstein's relativity theory - nuclear
>weapons and powerplants, cosmogology, the stuff they do at
>CERN - would turn out to be wrong.
>
>By all means - it's up to you to make that claim. Just be
>prepared to be asked thay *you* prove that your are right.
>It would take a lot more than a mere simulation you don't
>know how to do, of stuff you don't know, to convince anyone
>outside NTNU.
>
>Rune
>

On 23 Mar, 16:42, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> You still have not come up with any intelligent comments refuting my
> arguments.

There is avery good reasons for that: You have presented
no arguments to refute.

> Your resort to insults does not help.

What insults? I have only listed the factual errors,
blunders and misconceptions you have displayed througout
this thread.

The person(s) you *really* want to chat with are

1) The guy you see in the mirror each morning
2) Whoever might have led you down this path
   in the first place
3) Whoever you might have encountered in your
   work, who did *not* point out the obvious
   to you, as I have done over the last couple
   of days.

The facts remain: You don't have the faintest clue
what you are doing, at any level.

Rune

WWalker wrote:
> Hi Eric,
> 
> Sorry for the confusion. I will try to stick to top posting.
> 
> Regarding your question about what carries the information faster than
> light, I can not say for sure, but I suspect it is the virtual photon. The
> only thing I can say for sure is that the envelope of a narrow band
> modulated signal propagates undistortted, faster than light in the
> nearfield of a dipole source. If this is true then Relativity theory will
> need to be reevaluated. For more information, refer to my other paper:
> http://xxx.lanl.gov/pdf/physics/0702166

Being narrow band, the envelope is predictable. The narrower the band, 
the further the prediction (i.e. extrapolation) can be carried. (Think 
"coherence length".) The more predictable a phenomenon is, the more one 
can pretend to know of it (or delude oneself into believing one knows 
it) it in advance of its happening. Knowing the date of the next eclipse 
is not the same as receiving a signal from the future.

The phase velocity in a waveguide _always_ exceeds the speed of light in 
vacuo. Ask any radar engineer. You have rediscovered a triviality.

Your useless simulations are all done with steady state. Steady state 
carries no information. All information is in transients; non-redundant, 
unpredictable transients. If you can show transients propagating faster 
than light speed, people will listen.

Jerry
-- 
it reverses the order of the flow of a discussion.
Top posting seems unnatural to most people because

Steve,

The only thing one has to do to prove that information can be propagated
faster than light, is to simply demonstate it. The simulation below clearly
denonstrates that this is possible. Check it for yourself. Simply copy and
paste it into Mathematica. 

The simulation generates a random modulated 100ns span signal by adding a
50MHz,1V Peak Cosine to a 22.7MHz, 1.7V peak Cosine. Then the Modulation is
multiplied with 500MHz, 1V peak Cosine carrier. The reference envelope is
extracted by dividing by the carrier. 

The AM signal is then run through the transfer function of a light speed
propagating system [e^(iwr/c)] by adding phase terms (wr/c) to each
harmonic of the signal, where i is the complex number, w is the radial
frequency, r is the distance of field propagation (r=20cm). The envelope of
this light propagated signal is then determined by dividing by a phase
shifted (wr/c) carrier. 

The AM signal is then run through the Magnetic field component transfer
function of an electric dipole antenna with the known transfer function:
[e^(iwr/c)[-kr-i]] by adding phase terms
(wr/c-ArcCos[(-wr/c)/Sqrt[1+(wr/c)^2]]) to each harmonic of the signal. The
envelope of this dipole propagated signal is determined by dividing by a
phase shifted (wr/c-ArcCos[(-wr/c)/Sqrt[1+(wr/c)^2]]) carrier. Plots are
shown for all three signals with their extracted envelopes which align
perfectly with their signal. 

Finally the envelopes are plotted and a zoom of the plot clearly shows that
the information (modulation envelope) arrives earlier than a light speed
propagated signal. 


William

---------Begin Mathematica code (checked on ver 5.2 and ver7)---------

Signal
Sig = (A1*Cos[wm1 t] + A2*Cos[wm2 t] + 3) 2 Cos[wc t]
TrigReduce[Sig]
Carrier = Cos[wc t];
wc = 2 \[Pi] fc; wm1 = 2 \[Pi] fm1; wm2 = 2 \[Pi] fm2;
c = 3*10^8; fc = 500*10^6; fm1 = 50*10^6; fm2 = 
 22.7*10^6; A1 = 1; A2 = 1.7; r = 0.2;
Plot[Sig, {t, 0, 100*10^-9}, PlotPoints -> 300]
Plot[Carrier, {t, 0, 100*10^-9}, PlotPoints -> 300]
Signal Envelope
SigEnv = Sig/Carrier;
Plot[SigEnv, {t, 0, 100*10^-9}, PlotPoints -> 300]
Plot[{Sig, SigEnv}, {t, 0, 100*10^-9}, PlotPoints -> 300]
Light
Light = 6 Cos[t wc - Lth1] + A1 Cos[t wc - t wm1 - Lth2] + 
   A1 Cos[t wc + t wm1 - Lth3] + A2 Cos[t wc - t wm2 - Lth4] + 
   A2 Cos[t wc + t wm2 - Lth5];
Lth1 = 2 \[Pi] fc r/c;
Lth2 = 2 \[Pi] (fc - fm1) r/c;
Lth3 = 2 \[Pi] (fc + fm1) r/c;
Lth4 = 2 \[Pi] (fc - fm2) r/c;
Lth5 = 2 \[Pi] (fc + fm2) r/c;
Plot[Light, {t, 0, 100*10^-9}, PlotPoints -> 300]
Light Envelope
LightEnv = Light/Cos[t wc - Lth1];
Plot[LightEnv, {t, 0, 100*10^-9}, PlotPoints -> 300]
Plot[{Light, LightEnv}, {t, 0, 100*10^-9}, PlotPoints -> 300]
Ant
Ant = 6 Cos[t wc - Antth1] + A1 Cos[t wc - t wm1 - Antth2] + 
   A1 Cos[t wc + t wm1 - Antth3] + A2 Cos[t wc - t wm2 - Antth4] + 
   A2 Cos[t wc + t wm2 - Antth5];
Antth1 = 2 \[Pi] fc r/c - 
   ArcCos[-2 \[Pi] fc r/c/Sqrt[1 + (2 \[Pi] fc r/c)^2]];
Antth2 = 2 \[Pi] (fc - fm1) r/c - 
   ArcCos[-2 \[Pi] (fc - fm1) r/c/
      Sqrt[1 + (2 \[Pi] (fc - fm1) r/c)^2]];
Antth3 = 2 \[Pi] (fc + fm1) r/c - 
   ArcCos[-2 \[Pi] (fc + fm1) r/c/
      Sqrt[1 + (2 \[Pi] (fc + fm1) r/c)^2]];
Antth4 = 2 \[Pi] (fc - fm2) r/c - 
   ArcCos[-2 \[Pi] (fc - fm2) r/c/
      Sqrt[1 + (2 \[Pi] (fc - fm2) r/c)^2]];
Antth5 = 2 \[Pi] (fc + fm2) r/c - 
   ArcCos[-2 \[Pi] (fc + fm2) r/c/
      Sqrt[1 + (2 \[Pi] (fc + fm2) r/c)^2]];
Plot[Ant, {t, 0, 100*10^-9}, PlotPoints -> 300]
Ant Envelope
AntEnv = Ant/Cos[t wc - Antth1];
Plot[AntEnv, {t, 0, 100*10^-9}, PlotPoints -> 300]
Plot[{Ant, AntEnv}, {t, 0, 100*10^-9}, PlotPoints -> 300]
Envelope Plots
Plot[{SigEnv, AntEnv, LightEnv}, {t, 0, 100*10^-9}, 
 PlotStyle -> {RGBColor[1, 0, 0], RGBColor[0, 1, 0], 
   RGBColor[0, 0, 1]}]
Plot[{SigEnv, AntEnv, LightEnv}, {t, 3.5*10^-8, 3.6*10^-8}, 
 AxesOrigin -> {3.5*10^-8, 7}, 
 PlotStyle -> {RGBColor[1, 0, 0], RGBColor[0, 1, 0], 
   RGBColor[0, 0, 1]}]


----------------End Mathematica code------------------------

>>Rune,
>>
>>No one is interested in your emotional rantings. If you have something
>>intelligent to say about the system in discussion then lets talk. But
>>support your ideas with logic. I have given you logical arguments
>>supporting the superluminal conclusion, which ones can you prove are
>wrong.
>>If you can't then be quiet. Emotional rantings only make you look
>foolish.
>
>You are the one looking foolish up to now. If you want to claim you have
>perpetual motion, you need an *exceedingly* powerful argument before
anyone
>will stop laughing. If you want to claim you have infinite gain bandwidth
>product you need an *exceedingly* powerful argument before anyone will
stop
>laughing. If you want to claim you can carry information faster than
light
>you need to a) prove that people like Shannon and others were wrong, and
>that information and energy are not interchangeable terms, or b) that you
>have found a way to carry energy faster than light. So far, all you've
done
>it describe a variety of things that look like the phantom fast moving
>phase effects we all meet quite regularly. When amplitude or phase
>manipulation is really carrying information, its because those things are
>directly related to real energy manipulation.
>
>Steve
>
>

Jerry,

AM radio stations transmit narrow band information signals every day, just
turn on an AM radio and listen. Clearly narrow band signals can carry
information.

The information in an AM signal is the modulation and propagates at the
group speed. This is what I am saying propagates faster than light in the
nearfield.

In my simulations I generated a random signal by adding two Cosines with
different amplitudes and frequencies, which are not harmonic. This
modulation is then multiplied with a higher frequency Cosine carrier and
the signals are sent 20 cm across space through a light speed transfer
function and an electric dipole transfer functon. The envelopes are then
detected by dividing by the carrier and the envelopes are compared. The
results clearly show that the modulation envelope from the dipole arrives
earlier than the light speed propagated envelope.   

William 


>WWalker wrote:
>> Hi Eric,
>> 
>> Sorry for the confusion. I will try to stick to top posting.
>> 
>> Regarding your question about what carries the information faster than
>> light, I can not say for sure, but I suspect it is the virtual photon.
The
>> only thing I can say for sure is that the envelope of a narrow band
>> modulated signal propagates undistortted, faster than light in the
>> nearfield of a dipole source. If this is true then Relativity theory
will
>> need to be reevaluated. For more information, refer to my other paper:
>> http://xxx.lanl.gov/pdf/physics/0702166
>
>Being narrow band, the envelope is predictable. The narrower the band, 
>the further the prediction (i.e. extrapolation) can be carried. (Think 
>"coherence length".) The more predictable a phenomenon is, the more one 
>can pretend to know of it (or delude oneself into believing one knows 
>it) it in advance of its happening. Knowing the date of the next eclipse 
>is not the same as receiving a signal from the future.
>
>The phase velocity in a waveguide _always_ exceeds the speed of light in 
>vacuo. Ask any radar engineer. You have rediscovered a triviality.
>
>Your useless simulations are all done with steady state. Steady state 
>carries no information. All information is in transients; non-redundant, 
>unpredictable transients. If you can show transients propagating faster 
>than light speed, people will listen.
>
>Jerry
>-- 
>it reverses the order of the flow of a discussion.
>Top posting seems unnatural to most people because
>

WWalker wrote:
(top posting fixed)
>>> Rune,
>>>
>>> No one is interested in your emotional rantings. If you have something
>>> intelligent to say about the system in discussion then lets talk. But
>>> support your ideas with logic. I have given you logical arguments
>>> supporting the superluminal conclusion, which ones can you prove are
>> wrong.
>>> If you can't then be quiet. Emotional rantings only make you look
>> foolish.
>>
>> You are the one looking foolish up to now. If you want to claim you have
>> perpetual motion, you need an *exceedingly* powerful argument before
> anyone
>> will stop laughing. If you want to claim you have infinite gain bandwidth
>> product you need an *exceedingly* powerful argument before anyone will
> stop
>> laughing. If you want to claim you can carry information faster than
> light
>> you need to a) prove that people like Shannon and others were wrong, and
>> that information and energy are not interchangeable terms, or b) that you
>> have found a way to carry energy faster than light. So far, all you've
> done
>> it describe a variety of things that look like the phantom fast moving
>> phase effects we all meet quite regularly. When amplitude or phase
>> manipulation is really carrying information, its because those things are
>> directly related to real energy manipulation.
>>
 > Steve,
 >
 > The only thing one has to do to prove that information can be propagated
 > faster than light, is to simply demonstate it. The simulation below 
clearly
 > denonstrates that this is possible. Check it for yourself. Simply 
copy and
 > paste it into Mathematica.
 >
 > The simulation generates a random modulated 100ns span signal by adding a
 > 50MHz,1V Peak Cosine to a 22.7MHz, 1.7V peak Cosine. Then the 
Modulation is
 > multiplied with 500MHz, 1V peak Cosine carrier. The reference envelope is
 > extracted by dividing by the carrier.
 >
 > The AM signal is then run through the transfer function of a light speed
 > propagating system [e^(iwr/c)] by adding phase terms (wr/c) to each
 > harmonic of the signal, where i is the complex number, w is the radial
 > frequency, r is the distance of field propagation (r=20cm). The 
envelope of
 > this light propagated signal is then determined by dividing by a phase
 > shifted (wr/c) carrier.
 >
 > The AM signal is then run through the Magnetic field component transfer
 > function of an electric dipole antenna with the known transfer function:
 > [e^(iwr/c)[-kr-i]] by adding phase terms
 > (wr/c-ArcCos[(-wr/c)/Sqrt[1+(wr/c)^2]]) to each harmonic of the 
signal. The
 > envelope of this dipole propagated signal is determined by dividing by a
 > phase shifted (wr/c-ArcCos[(-wr/c)/Sqrt[1+(wr/c)^2]]) carrier. Plots are
 > shown for all three signals with their extracted envelopes which align
 > perfectly with their signal.
 >
 > Finally the envelopes are plotted and a zoom of the plot clearly 
shows that
 > the information (modulation envelope) arrives earlier than a light speed
 > propagated signal.

By that logic, we can already _travel_ faster than light, and I can 
prove it -- just watch any episode of Star Trek!

But I'm not holding my breath for a scenic tour of Antares.

-- 
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Actually, bottom posting is the preferred method, since a single entry 
can be read logically in order.   I'm top-posting here just because 
mixing top and bottom is worse than top posting.

It seems to me that you're not grasping what people are trying to tell 
you.   Jerry mentioned a relevant article, but I'll post a link for you:

http://www.dsprelated.com/showarticle/54.php

Study that carefully, because it describes completely the phenomenon 
that you're seeing, and it has nothing to do with propagation faster 
than the speed of light or predicting the future.   It is the nature of 
narrowband signals that they can be predicted in the short term, unless 
a perturbation arrives.   This is what people have been trying to point 
out to you, and this (or some other phenomenon other than exceeding c) 
is what you're seeing.

You're not the first to be lured down this path and you won't be the last.

On 3/23/2010 11:05 AM, WWalker wrote:
> Jerry,
>
> AM radio stations transmit narrow band information signals every day, just
> turn on an AM radio and listen. Clearly narrow band signals can carry
> information.
>
> The information in an AM signal is the modulation and propagates at the
> group speed. This is what I am saying propagates faster than light in the
> nearfield.
>
> In my simulations I generated a random signal by adding two Cosines with
> different amplitudes and frequencies, which are not harmonic. This
> modulation is then multiplied with a higher frequency Cosine carrier and
> the signals are sent 20 cm across space through a light speed transfer
> function and an electric dipole transfer functon. The envelopes are then
> detected by dividing by the carrier and the envelopes are compared. The
> results clearly show that the modulation envelope from the dipole arrives
> earlier than the light speed propagated envelope.
>
> William
>
>
>> WWalker wrote:
>>> Hi Eric,
>>>
>>> Sorry for the confusion. I will try to stick to top posting.
>>>
>>> Regarding your question about what carries the information faster than
>>> light, I can not say for sure, but I suspect it is the virtual photon.
> The
>>> only thing I can say for sure is that the envelope of a narrow band
>>> modulated signal propagates undistortted, faster than light in the
>>> nearfield of a dipole source. If this is true then Relativity theory
> will
>>> need to be reevaluated. For more information, refer to my other paper:
>>> http://xxx.lanl.gov/pdf/physics/0702166
>>
>> Being narrow band, the envelope is predictable. The narrower the band,
>> the further the prediction (i.e. extrapolation) can be carried. (Think
>> "coherence length".) The more predictable a phenomenon is, the more one
>> can pretend to know of it (or delude oneself into believing one knows
>> it) it in advance of its happening. Knowing the date of the next eclipse
>> is not the same as receiving a signal from the future.
>>
>> The phase velocity in a waveguide _always_ exceeds the speed of light in
>> vacuo. Ask any radar engineer. You have rediscovered a triviality.
>>
>> Your useless simulations are all done with steady state. Steady state
>> carries no information. All information is in transients; non-redundant,
>> unpredictable transients. If you can show transients propagating faster
>> than light speed, people will listen.
>>
>> Jerry
>> --
>> it reverses the order of the flow of a discussion.
>> Top posting seems unnatural to most people because
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

WWalker wrote:
> Steve,
> 
> The only thing one has to do to prove that information can be propagated
> faster than light, is to simply demonstate it. The simulation below clearly
> denonstrates that this is possible. Check it for yourself. Simply copy and
> paste it into Mathematica. 

That's not the only thing. You also have to show that the demonstration 
is about information. Yours is not.

> The simulation generates a random modulated 100ns span signal by adding a
> 50MHz,1V Peak Cosine to a 22.7MHz, 1.7V peak Cosine. Then the Modulation is
> multiplied with 500MHz, 1V peak Cosine carrier. The reference envelope is
> extracted by dividing by the carrier. 

That is deterministic, not random.  Once the waveform starts, you can 
announce what it will be tomorrow. No information at all!

   ...

> Finally the envelopes are plotted and a zoom of the plot clearly shows that
> the information (modulation envelope) arrives earlier than a light speed
> propagated signal. 

You knew -- or should have known -- before submitting anything to 
mathematical analysis what the outcome would be. There *is* no information.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

WWalker wrote:
> Jerry,
> 
> AM radio stations transmit narrow band information signals every day, just
> turn on an AM radio and listen. Clearly narrow band signals can carry
> information.

The limited bandwidth of AM channels limits their information capacity. 
Knowing the two-sided bandwidth of such a channel is 5 KHz should tell 
you that the envelope amplitudes only 100 microseconds apart will be 
highly correlated. The envelope amplitude 100 microseconds hence will br 
highly correlated with what it is now. That's prediction.

> The information in an AM signal is the modulation and propagates at the
> group speed. This is what I am saying propagates faster than light in the
> nearfield.

You see the same effect with narrow-band signals undergoing anomalous 
dispersion. The group (but not the energy) velocity exceeds that of light.

> In my simulations I generated a random signal by adding two Cosines with
> different amplitudes and frequencies, which are not harmonic. This
> modulation is then multiplied with a higher frequency Cosine carrier and
> the signals are sent 20 cm across space through a light speed transfer
> function and an electric dipole transfer functon. The envelopes are then
> detected by dividing by the carrier and the envelopes are compared. The
> results clearly show that the modulation envelope from the dipole arrives
> earlier than the light speed propagated envelope.  

What is random about something described by such simple mathematics?

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

Jerry Avins wrote:
> WWalker wrote:
>> Jerry,
>>
>> AM radio stations transmit narrow band information signals every day, 
>> just
>> turn on an AM radio and listen. Clearly narrow band signals can carry
>> information.
> 
> The limited bandwidth of AM channels limits their information capacity. 
> Knowing the two-sided bandwidth of such a channel is 5 KHz should tell 
> you that the envelope amplitudes only 100 microseconds apart will be 
> highly correlated. The envelope amplitude 100 microseconds hence will br 
> highly correlated with what it is now. That's prediction.
> 
>> The information in an AM signal is the modulation and propagates at the
>> group speed. This is what I am saying propagates faster than light in the
>> nearfield.
> 
> You see the same effect with narrow-band signals undergoing anomalous 
> dispersion. The group (but not the energy) velocity exceeds that of light.
> 
>> In my simulations I generated a random signal by adding two Cosines with
>> different amplitudes and frequencies, which are not harmonic. This
>> modulation is then multiplied with a higher frequency Cosine carrier and
>> the signals are sent 20 cm across space through a light speed transfer
>> function and an electric dipole transfer functon. The envelopes are then
>> detected by dividing by the carrier and the envelopes are compared. The
>> results clearly show that the modulation envelope from the dipole arrives
>> earlier than the light speed propagated envelope.  
> 
> What is random about something described by such simple mathematics?

See also http://pre.aps.org/abstract/PRE/v65/i3/e036608
> Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

Jerry Avins <jya@ieee.org> wrote:
> WWalker wrote:
 
>> The only thing one has to do to prove that information can be propagated
>> faster than light, is to simply demonstate it. The simulation below clearly
>> denonstrates that this is possible. Check it for yourself. Simply copy and
>> paste it into Mathematica. 
 
> That's not the only thing. You also have to show that the demonstration 
> is about information. Yours is not.

There are some interesting things that can be done in near field.
One is the near field microscope, which can resolve details much
smaller than the wavelength of light used.  

As for information transfer, there are materials with a group
velocity higher than C at certain frequencies.  In the usual case,
you still can't transfer information faster than C through such
materials.  One reason is that they have strong absorption at
that point, but for near field maybe that isn't so bad.

In general, though, useful communication is far field.  The
ability to transfer, say, one bit/second over a short distance,
in slightly less the d/c isn't useful.

-- glen

Eric Jacobsen <eric.jacobsen@ieee.org> wrote:
> Actually, bottom posting is the preferred method, since a single entry 
> can be read logically in order.   I'm top-posting here just because 
> mixing top and bottom is worse than top posting.

Personally, I am not against top posting given two conditions:

First, and most important, no likely follow-ups should be expected.
If someone just says "I agree", or "me, too", then there really isn't
much else to say.  (Me, three?)

Second, is that the normal place for the follow-up material is
many pages down.  Of course, one should do appropriate snipping,
and some people don't do that.  If there is no new material in
the first few pages, I am likely to just go on to the next post.

In the case that someone does need to follow-up such a post,
often the best thing is to snip away everything following the
new post and reply just to that.  That works about as well as
anything else,  especially if the follow-up isn't really related
to the previous post.  (Or often it is indirectly related, but
that isn't relevant to later posts.)

-- glen

On 23 Mar, 21:06, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
> Actually, bottom posting is the preferred method, since a single entry
> can be read logically in order. =A0 I'm top-posting here just because
> mixing top and bottom is worse than top posting.
>
> It seems to me that you're not grasping what people are trying to tell
> you. =A0 Jerry mentioned a relevant article, but I'll post a link for you=
:
>
> http://www.dsprelated.com/showarticle/54.php

No, this is far simpler than that. Andor's example was a
IIR function with poles. Ther is no feedback in the dipole.

This thread is about wave physics 101 stuff that anyone
messing with array processing or wavefield analysis needs
to know. And is expected to know.

> You're not the first to be lured down this path and you won't be the last=
..

It's a matter of education. Or lack of such.

Below is a crude *simulation* I made for matlab. Call it as

FasterThanLightMovie(60,16); % Oblique angle at 60 degrees,
                             % 16 frames in animation

and see the simulation I hinted at a couple of days ago:
The wave 2D field propagates in the positive direction
along the x axis. There are two observations made of
the field, one along the propagation axis (the blue
graph / line) and one at an oblique angle (the red graph /
line).

In the upper plot the snapshot along the two lines
are plotted. Do note the apparent speed of the zero
crossing as it propagates donw the observation throughout
a cycle (marked as a circle in the top plot and a cross
in the lower plot). It is seen that the apparent speed
along the oblique observation is far higher than the
true, free field speed at which the wave travels down
the x axis.

If our friend WW splits up his simulation in monopole
sources, he will be able to see exactly the same kind of
effect but in a cylindrical or spherical coordinate system.

So following WW's logic, all we need to do to obtain
faster-than-light communication, is to observe the
wave field along an axis oblique to the actual axis
of propagation, thus requiring the information to travel
a longer distance.  Yeah. Right.

Again, this is trivial material. It's only a matter of a
bare minimum of knowledge about wave physics, simulation
design, and data analysis that is needed to fully pull
this stuff apart and see what is actually going on.

Rune

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function FasterThanLightMovie(phi,Nframes)
    Phi =3D phi/180*pi;
    xv =3D [-1:0.01:2];
    yv =3D [-1;3];
    xv =3D reshape(xv,1,length(xv));
    Lref =3D [0:0.01:1];
    Loblique =3D Lref*cos(Phi);
    c =3D 3e8;
    f =3D 3e8;
    T =3D 1/c;
    tv =3D (0:Nframes-1)*T/Nframes;
    for n=3D1:Nframes
        clf
       s =3D ones(2,1)*sin(2*pi*f*(tv(n) - xv / c));
       subplot(2,1,1)
       plot(Lref,sin(2*pi*f*(tv(n)-Lref/c)),'b')
       hold on
       plot(Lref,sin(2*pi*f*(tv(n)-Loblique/c)),'r')
       plot(c*tv(n),0,'ob')
       plot(c*tv(n)/cos(Phi),0,'or')
       ax =3D axis;
       plot(ax(1:2),[0,0],'k')

       subplot(2,1,2)
       imagesc(xv,yv,s)
       set(gca,'dataaspectratio',[1,1,1])
       set(gca,'ydir','normal')
       hold on
       plot([0,1],[0,0],'b','linewidth',2)
       plot([0,1],[0,tan(Phi)],'r','linewidth',2)
       plot(c*tv(n),0,'xb','markersize',5,'linewidth',4)
       plot(c*tv(n),c*tv(n)*tan(Phi),'xr','markersize',5,'linewidth',
4)
       colormap(gray)
       drawnow
       pause(0.3)
    end
end

On 3/23/2010 4:51 PM, Rune Allnor wrote:
> On 23 Mar, 21:06, Eric Jacobsen<eric.jacob...@ieee.org>  wrote:
>> Actually, bottom posting is the preferred method, since a single entry
>> can be read logically in order.   I'm top-posting here just because
>> mixing top and bottom is worse than top posting.
>>
>> It seems to me that you're not grasping what people are trying to tell
>> you.   Jerry mentioned a relevant article, but I'll post a link for you:
>>
>> http://www.dsprelated.com/showarticle/54.php
>
> No, this is far simpler than that. Andor's example was a
> IIR function with poles. Ther is no feedback in the dipole.
>
> This thread is about wave physics 101 stuff that anyone
> messing with array processing or wavefield analysis needs
> to know. And is expected to know.
>
>> You're not the first to be lured down this path and you won't be the last.
>
> It's a matter of education. Or lack of such.
>
> Below is a crude *simulation* I made for matlab. Call it as
>
> FasterThanLightMovie(60,16); % Oblique angle at 60 degrees,
>                               % 16 frames in animation
>
> and see the simulation I hinted at a couple of days ago:
> The wave 2D field propagates in the positive direction
> along the x axis. There are two observations made of
> the field, one along the propagation axis (the blue
> graph / line) and one at an oblique angle (the red graph /
> line).
>
> In the upper plot the snapshot along the two lines
> are plotted. Do note the apparent speed of the zero
> crossing as it propagates donw the observation throughout
> a cycle (marked as a circle in the top plot and a cross
> in the lower plot). It is seen that the apparent speed
> along the oblique observation is far higher than the
> true, free field speed at which the wave travels down
> the x axis.
>
> If our friend WW splits up his simulation in monopole
> sources, he will be able to see exactly the same kind of
> effect but in a cylindrical or spherical coordinate system.
>
> So following WW's logic, all we need to do to obtain
> faster-than-light communication, is to observe the
> wave field along an axis oblique to the actual axis
> of propagation, thus requiring the information to travel
> a longer distance.  Yeah. Right.
>
> Again, this is trivial material. It's only a matter of a
> bare minimum of knowledge about wave physics, simulation
> design, and data analysis that is needed to fully pull
> this stuff apart and see what is actually going on.
>
> Rune
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> function FasterThanLightMovie(phi,Nframes)
>      Phi = phi/180*pi;
>      xv = [-1:0.01:2];
>      yv = [-1;3];
>      xv = reshape(xv,1,length(xv));
>      Lref = [0:0.01:1];
>      Loblique = Lref*cos(Phi);
>      c = 3e8;
>      f = 3e8;
>      T = 1/c;
>      tv = (0:Nframes-1)*T/Nframes;
>      for n=1:Nframes
>          clf
>         s = ones(2,1)*sin(2*pi*f*(tv(n) - xv / c));
>         subplot(2,1,1)
>         plot(Lref,sin(2*pi*f*(tv(n)-Lref/c)),'b')
>         hold on
>         plot(Lref,sin(2*pi*f*(tv(n)-Loblique/c)),'r')
>         plot(c*tv(n),0,'ob')
>         plot(c*tv(n)/cos(Phi),0,'or')
>         ax = axis;
>         plot(ax(1:2),[0,0],'k')
>
>         subplot(2,1,2)
>         imagesc(xv,yv,s)
>         set(gca,'dataaspectratio',[1,1,1])
>         set(gca,'ydir','normal')
>         hold on
>         plot([0,1],[0,0],'b','linewidth',2)
>         plot([0,1],[0,tan(Phi)],'r','linewidth',2)
>         plot(c*tv(n),0,'xb','markersize',5,'linewidth',4)
>         plot(c*tv(n),c*tv(n)*tan(Phi),'xr','markersize',5,'linewidth',
> 4)
>         colormap(gray)
>         drawnow
>         pause(0.3)
>      end
> end


You sim doesn't run very well under my version of Octave, but the bit 
about the phase velocity on oblique angles is fundamental.   I haven't 
been able to sort out what WW is doing well enough to know for certain 
that's the issue, but in his paper the waveforms he compares don't prove 
anything.

I was at least trying to get him to see, as Jerry has been, that if a 
transient is introduced it'll expose his error.   Andor's paper does 
that marvelously.  I was hoping the idea would stick.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric,

Interesting article, but I don't see how it applies to my system. The
system described in the paper is a bandpass filter in a feedback loop,
where the bandpass filter phase function is altered by the feedback. The
feedback forces the endpoints of the phase to zero, creating regions of
possitive slope, which yield negative group delays for narrow band signals.
This causes narrow band signals at the output of the circuit appear to
arrive earlier than signals at the input of the circuit. Because the
information in the signals is slightly redundant, the circuit is able to
reconstruct future parts of the signal from the present part of the
signal.


First of all, this is a circuit which alters the phase function with
respect to time and not space, as it is in my system. The phase function in
the circuit is not due to wave propagaton, where mine is.

Secondly,unlike the circuit, my system is causal. The recieved signal in my
system arrives after the signal is transmitted. It just travels faster than
light. 

Thirdly, the negative group delay in the circuit was accomplished by using
feedback which does not exist in my system.


Information (modulations) are clearly transmitted using narrowband AM radio
communication, just listen to an AM radio. The simulation I presented
simply shows that random AM modulations arrive undistorted across space, in
the nearfield, earlier than a light speed propagated signal.

Signal purturbations can not be used to measure the signal propagation in
the nearfield because they distort in the nearfield, and group speed has no
meaning if the signal distorts as it propagates. 

William

 

>Actually, bottom posting is the preferred method, since a single entry 
>can be read logically in order.   I'm top-posting here just because 
>mixing top and bottom is worse than top posting.
>
>It seems to me that you're not grasping what people are trying to tell 
>you.   Jerry mentioned a relevant article, but I'll post a link for you:
>
>http://www.dsprelated.com/showarticle/54.php
>
>Study that carefully, because it describes completely the phenomenon 
>that you're seeing, and it has nothing to do with propagation faster 
>than the speed of light or predicting the future.   It is the nature of 
>narrowband signals that they can be predicted in the short term, unless 
>a perturbation arrives.   This is what people have been trying to point 
>out to you, and this (or some other phenomenon other than exceeding c) 
>is what you're seeing.
>
>You're not the first to be lured down this path and you won't be the
last.
>
>On 3/23/2010 11:05 AM, WWalker wrote:
>> Jerry,
>>
>> AM radio stations transmit narrow band information signals every day,
just
>> turn on an AM radio and listen. Clearly narrow band signals can carry
>> information.
>>
>> The information in an AM signal is the modulation and propagates at the
>> group speed. This is what I am saying propagates faster than light in
the
>> nearfield.
>>
>> In my simulations I generated a random signal by adding two Cosines
with
>> different amplitudes and frequencies, which are not harmonic. This
>> modulation is then multiplied with a higher frequency Cosine carrier
and
>> the signals are sent 20 cm across space through a light speed transfer
>> function and an electric dipole transfer functon. The envelopes are
then
>> detected by dividing by the carrier and the envelopes are compared. The
>> results clearly show that the modulation envelope from the dipole
arrives
>> earlier than the light speed propagated envelope.
>>
>> William
>>
>>
>>> WWalker wrote:
>>>> Hi Eric,
>>>>
>>>> Sorry for the confusion. I will try to stick to top posting.
>>>>
>>>> Regarding your question about what carries the information faster
than
>>>> light, I can not say for sure, but I suspect it is the virtual
photon.
>> The
>>>> only thing I can say for sure is that the envelope of a narrow band
>>>> modulated signal propagates undistortted, faster than light in the
>>>> nearfield of a dipole source. If this is true then Relativity theory
>> will
>>>> need to be reevaluated. For more information, refer to my other
paper:
>>>> http://xxx.lanl.gov/pdf/physics/0702166
>>>
>>> Being narrow band, the envelope is predictable. The narrower the band,
>>> the further the prediction (i.e. extrapolation) can be carried. (Think
>>> "coherence length".) The more predictable a phenomenon is, the more
one
>>> can pretend to know of it (or delude oneself into believing one knows
>>> it) it in advance of its happening. Knowing the date of the next
eclipse
>>> is not the same as receiving a signal from the future.
>>>
>>> The phase velocity in a waveguide _always_ exceeds the speed of light
in
>>> vacuo. Ask any radar engineer. You have rediscovered a triviality.
>>>
>>> Your useless simulations are all done with steady state. Steady state
>>> carries no information. All information is in transients;
non-redundant,
>>> unpredictable transients. If you can show transients propagating
faster
>>> than light speed, people will listen.
>>>
>>> Jerry
>>> --
>>> it reverses the order of the flow of a discussion.
>>> Top posting seems unnatural to most people because
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

WWalker wrote:
> Eric,
> 
> Interesting article, but I don't see how it applies to my system.

Prior art:

http://www.google.com/patents?id=csYDAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q=&f=false




Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

On 3/23/2010 6:06 PM, WWalker wrote:
> Eric,
>
> Interesting article, but I don't see how it applies to my system. The
> system described in the paper is a bandpass filter in a feedback loop,
> where the bandpass filter phase function is altered by the feedback. The
> feedback forces the endpoints of the phase to zero, creating regions of
> possitive slope, which yield negative group delays for narrow band signals.
> This causes narrow band signals at the output of the circuit appear to
> arrive earlier than signals at the input of the circuit. Because the
> information in the signals is slightly redundant, the circuit is able to
> reconstruct future parts of the signal from the present part of the
> signal.

Snipped context to allow bottom-posting.

Feedback is not necessary to produce negative group delay.   Here's 
another example with a passive notch filter that exhibits negative group 
delay.

http://www.radiolab.com.au/DesignFile/DN004.pdf

It doesn't matter what's inside a black box if it has a negative group 
delay characteristic if the transfer function is LTI.   Whether there's 
feedback or not in the implementation is inconsequential.   Consider 
that the passive notch filter could also be implemented as an active 
circuit with feedback, and if the transfer functions are equivalent they 
are functionally equivalent.   This is fundamental.  I don't think the 
feedback has anything to do with it.

You're argument on the redundancy, though, is spot-on.   Note that, as 
others have already pointed out multiple times, the signals you're using 
in your experiment are HIGHLY redundant, so much so that they carry 
almost no information.   These signals are therefore not suitable for 
proving anything about information propagation.


> First of all, this is a circuit which alters the phase function with
> respect to time and not space, as it is in my system. The phase function in
> the circuit is not due to wave propagaton, where mine is.

As far as I've been able to tell, your evidence is based on a 
simulation, in which case dimensionalities are abstractions.   You are 
not performing anything in either time or space, you're performing a 
numerical simulation.  Space-time transforms are not at all unusual and 
it is likely that a substitution is easily performed.  Nothing has 
propagated in your simulation in either time or space.

> Secondly,unlike the circuit, my system is causal. The recieved signal in my
> system arrives after the signal is transmitted. It just travels faster than
> light.

Uh, the circuit is causal.  That was the point.

You have not demonstrated that your system is causal or not causal. 
That cannot be concluded using the waveforms you show in your paper due 
to the high determinism and narrow band characteristics.

> Thirdly, the negative group delay in the circuit was accomplished by using
> feedback which does not exist in my system.

As I stated above, this is inconsequential.


> Information (modulations) are clearly transmitted using narrowband AM radio
> communication, just listen to an AM radio. The simulation I presented
> simply shows that random AM modulations arrive undistorted across space, in
> the nearfield, earlier than a light speed propagated signal.

Your simulation does not demonstrate that.  Turn the signal off, even at 
a zero crossing if you want to minimize perturbations, and see what happens.

> Signal purturbations can not be used to measure the signal propagation in
> the nearfield because they distort in the nearfield, and group speed has no
> meaning if the signal distorts as it propagates.
>
> William

If you cannot use a perturbation (i.e., information transmission) to 
measure signal propagation then you cannot demonstrate the speed of 
information propagation.   Until you can actually demonstrate something 
other than phase velocity (which is NOT information transmission and 
many here have acknowledged can be faster than c, as do I), then you 
cannot make the conclusions that you are claiming.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Jerry,

The signal is random for the detection method I used. I would agree with
you if I had used a curvefitting envelope detection method. But by simply
dividing by the carrier, the detector is simply decoding as the signal
comes by. The proof is that if I use a curvefitting detection method, I
would need to sample many cycles of the signal to get a good match. But
with the detection method I am using, I get the envelope at the beginning
of the signal and at each iteration point.

William

>WWalker wrote:
>> Steve,
>> 
>> The only thing one has to do to prove that information can be
propagated
>> faster than light, is to simply demonstate it. The simulation below
clearly
>> denonstrates that this is possible. Check it for yourself. Simply copy
and
>> paste it into Mathematica. 
>
>That's not the only thing. You also have to show that the demonstration 
>is about information. Yours is not.
>
>> The simulation generates a random modulated 100ns span signal by adding
a
>> 50MHz,1V Peak Cosine to a 22.7MHz, 1.7V peak Cosine. Then the Modulation
is
>> multiplied with 500MHz, 1V peak Cosine carrier. The reference envelope
is
>> extracted by dividing by the carrier. 
>
>That is deterministic, not random.  Once the waveform starts, you can 
>announce what it will be tomorrow. No information at all!
>
>   ...
>
>> Finally the envelopes are plotted and a zoom of the plot clearly shows
that
>> the information (modulation envelope) arrives earlier than a light
speed
>> propagated signal. 
>
>You knew -- or should have known -- before submitting anything to 
>mathematical analysis what the outcome would be. There *is* no
information.
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

Vladimir,

Interesting patent but the idea presented is very different from the one I
am proposing. Many of the ideas being discussed in this thread are
published in my Ph.D. thesis submitted in 1997 at ETH Zurich, Switzerland.
Since I have published most of what I have presneted, I doubt a patent
would be possible. 

William

>
>
>WWalker wrote:
>> Eric,
>> 
>> Interesting article, but I don't see how it applies to my system.
>
>Prior art:
>
>http://www.google.com/patents?id=csYDAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q=&f=false
>
>
>
>
>Vladimir Vassilevsky
>DSP and Mixed Signal Design Consultant
>http://www.abvolt.com
>

>On 3/23/2010 6:06 PM, WWalker wrote:
>> Eric,
>>
>> Interesting article, but I don't see how it applies to my system. The
>> system described in the paper is a bandpass filter in a feedback loop,
>> where the bandpass filter phase function is altered by the feedback.
The
>> feedback forces the endpoints of the phase to zero, creating regions of
>> possitive slope, which yield negative group delays for narrow band
signals.
>> This causes narrow band signals at the output of the circuit appear to
>> arrive earlier than signals at the input of the circuit. Because the
>> information in the signals is slightly redundant, the circuit is able
to
>> reconstruct future parts of the signal from the present part of the
>> signal.
>
>Snipped context to allow bottom-posting.
>
>Feedback is not necessary to produce negative group delay.   Here's 
>another example with a passive notch filter that exhibits negative group 
>delay.
>
>http://www.radiolab.com.au/DesignFile/DN004.pdf
>
>It doesn't matter what's inside a black box if it has a negative group 
>delay characteristic if the transfer function is LTI.   Whether there's 
>feedback or not in the implementation is inconsequential.   Consider 
>that the passive notch filter could also be implemented as an active 
>circuit with feedback, and if the transfer functions are equivalent they 
>are functionally equivalent.   This is fundamental.  I don't think the 
>feedback has anything to do with it.
>
>You're argument on the redundancy, though, is spot-on.   Note that, as 
>others have already pointed out multiple times, the signals you're using 
>in your experiment are HIGHLY redundant, so much so that they carry 
>almost no information.   These signals are therefore not suitable for 
>proving anything about information propagation.
>
>
>> First of all, this is a circuit which alters the phase function with
>> respect to time and not space, as it is in my system. The phase function
in
>> the circuit is not due to wave propagaton, where mine is.
>
>As far as I've been able to tell, your evidence is based on a 
>simulation, in which case dimensionalities are abstractions.   You are 
>not performing anything in either time or space, you're performing a 
>numerical simulation.  Space-time transforms are not at all unusual and 
>it is likely that a substitution is easily performed.  Nothing has 
>propagated in your simulation in either time or space.
>
>> Secondly,unlike the circuit, my system is causal. The recieved signal in
my
>> system arrives after the signal is transmitted. It just travels faster
than
>> light.
>
>Uh, the circuit is causal.  That was the point.
>
>You have not demonstrated that your system is causal or not causal. 
>That cannot be concluded using the waveforms you show in your paper due 
>to the high determinism and narrow band characteristics.
>
>> Thirdly, the negative group delay in the circuit was accomplished by
using
>> feedback which does not exist in my system.
>
>As I stated above, this is inconsequential.
>
>
>> Information (modulations) are clearly transmitted using narrowband AM
radio
>> communication, just listen to an AM radio. The simulation I presented
>> simply shows that random AM modulations arrive undistorted across space,
in
>> the nearfield, earlier than a light speed propagated signal.
>
>Your simulation does not demonstrate that.  Turn the signal off, even at 
>a zero crossing if you want to minimize perturbations, and see what
happens.
>
>> Signal purturbations can not be used to measure the signal propagation
in
>> the nearfield because they distort in the nearfield, and group speed has
no
>> meaning if the signal distorts as it propagates.
>>
>> William
>
>If you cannot use a perturbation (i.e., information transmission) to 
>measure signal propagation then you cannot demonstrate the speed of 
>information propagation.   Until you can actually demonstrate something 
>other than phase velocity (which is NOT information transmission and 
>many here have acknowledged can be faster than c, as do I), then you 
>cannot make the conclusions that you are claiming.
>
Well he doesn't have to actually demonstrate a perturbation going faster
than light. If he could demonstrate energy travelling faster than light, it
would be equivalent. However, only one person here doesn't seem to grasp
that this ain't gonna happen.

Steve

WWalker wrote:

   ...

> Secondly,unlike the circuit, my system is causal. The recieved signal in my
> system arrives after the signal is transmitted. It just travels faster than
> light. 

Andor's circuit can be built from real parts. How could it not be causal?

> Thirdly, the negative group delay in the circuit was accomplished by using
> feedback which does not exist in my system.

Negative group delay is just that, no matter how produced. Test your 
system with real transients.

> Information (modulations) are clearly transmitted using narrowband AM radio
> communication, just listen to an AM radio. The simulation I presented
> simply shows that random AM modulations arrive undistorted across space, in
> the nearfield, earlier than a light speed propagated signal.

You don't seem to know what "random" really means. 
http://en.wikipedia.org/wiki/Randomness might help.

> Signal purturbations can not be used to measure the signal propagation in
> the nearfield because they distort in the nearfield, and group speed has no
> meaning if the signal distorts as it propagates. 

True randomness guarantees perturbations.

> William

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

steveu wrote:

>     ... only one person here doesn't seem to grasp
> that this ain't gonna happen.

It was the subject of his thesis and he passed his defence, so it must 
be valid. Isn't that how it goes?

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 3/23/2010 9:02 PM, Jerry Avins wrote:
> steveu wrote:
>
>> ... only one person here doesn't seem to grasp
>> that this ain't gonna happen.
>
> It was the subject of his thesis and he passed his defence, so it must
> be valid. Isn't that how it goes?
>
> Jerry

I'm struggling to believe that this is true.   That's a pretty sad 
indictment of that institution if this got by a PhD committee.

I suspect there's more to this story.  There's a number of things that 
don't make sense here, beyond the obvious claims.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric,

There is fundamental difference between a phase shift caused by a filter
and a time delay caused by wave propagation across a region of space. The
Op Amp filter circuit is simply phase shifting the harmonic components of
the signal such that the overall signal appears like it has arrived before
it was transmitted. The circuit is not really predicting the signal it is
only phase shifting it.

In my system, the time delay of the signal is completely due to wave
propagation across space. It is not a filter.

The simulation I presented simply shows the time delay of the modulation of
an AM signal transmission between two nearfield dipole antennas. If you
zoom in one can see that the modulations arrive earlier than a light
propagated signal. 

This is not phase velocity, this is group velocity i.e. time delay of the
envelope.

William




>On 3/23/2010 6:06 PM, WWalker wrote:
>> Eric,
>>
>> Interesting article, but I don't see how it applies to my system. The
>> system described in the paper is a bandpass filter in a feedback loop,
>> where the bandpass filter phase function is altered by the feedback.
The
>> feedback forces the endpoints of the phase to zero, creating regions of
>> possitive slope, which yield negative group delays for narrow band
signals.
>> This causes narrow band signals at the output of the circuit appear to
>> arrive earlier than signals at the input of the circuit. Because the
>> information in the signals is slightly redundant, the circuit is able
to
>> reconstruct future parts of the signal from the present part of the
>> signal.
>
>Snipped context to allow bottom-posting.
>
>Feedback is not necessary to produce negative group delay.   Here's 
>another example with a passive notch filter that exhibits negative group 
>delay.
>
>http://www.radiolab.com.au/DesignFile/DN004.pdf
>
>It doesn't matter what's inside a black box if it has a negative group 
>delay characteristic if the transfer function is LTI.   Whether there's 
>feedback or not in the implementation is inconsequential.   Consider 
>that the passive notch filter could also be implemented as an active 
>circuit with feedback, and if the transfer functions are equivalent they 
>are functionally equivalent.   This is fundamental.  I don't think the 
>feedback has anything to do with it.
>
>You're argument on the redundancy, though, is spot-on.   Note that, as 
>others have already pointed out multiple times, the signals you're using 
>in your experiment are HIGHLY redundant, so much so that they carry 
>almost no information.   These signals are therefore not suitable for 
>proving anything about information propagation.
>
>
>> First of all, this is a circuit which alters the phase function with
>> respect to time and not space, as it is in my system. The phase function
in
>> the circuit is not due to wave propagaton, where mine is.
>
>As far as I've been able to tell, your evidence is based on a 
>simulation, in which case dimensionalities are abstractions.   You are 
>not performing anything in either time or space, you're performing a 
>numerical simulation.  Space-time transforms are not at all unusual and 
>it is likely that a substitution is easily performed.  Nothing has 
>propagated in your simulation in either time or space.
>
>> Secondly,unlike the circuit, my system is causal. The recieved signal in
my
>> system arrives after the signal is transmitted. It just travels faster
than
>> light.
>
>Uh, the circuit is causal.  That was the point.
>
>You have not demonstrated that your system is causal or not causal. 
>That cannot be concluded using the waveforms you show in your paper due 
>to the high determinism and narrow band characteristics.
>
>> Thirdly, the negative group delay in the circuit was accomplished by
using
>> feedback which does not exist in my system.
>
>As I stated above, this is inconsequential.
>
>
>> Information (modulations) are clearly transmitted using narrowband AM
radio
>> communication, just listen to an AM radio. The simulation I presented
>> simply shows that random AM modulations arrive undistorted across space,
in
>> the nearfield, earlier than a light speed propagated signal.
>
>Your simulation does not demonstrate that.  Turn the signal off, even at 
>a zero crossing if you want to minimize perturbations, and see what
happens.
>
>> Signal purturbations can not be used to measure the signal propagation
in
>> the nearfield because they distort in the nearfield, and group speed has
no
>> meaning if the signal distorts as it propagates.
>>
>> William
>
>If you cannot use a perturbation (i.e., information transmission) to 
>measure signal propagation then you cannot demonstrate the speed of 
>information propagation.   Until you can actually demonstrate something 
>other than phase velocity (which is NOT information transmission and 
>many here have acknowledged can be faster than c, as do I), then you 
>cannot make the conclusions that you are claiming.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Eric Jacobsen wrote:
> On 3/23/2010 9:02 PM, Jerry Avins wrote:
>> steveu wrote:
>>
>>> ... only one person here doesn't seem to grasp
>>> that this ain't gonna happen.
>>
>> It was the subject of his thesis and he passed his defence, so it must
>> be valid. Isn't that how it goes?
>>
>> Jerry
> 
> I'm struggling to believe that this is true.   That's a pretty sad 
> indictment of that institution if this got by a PhD committee.
> 
> I suspect there's more to this story.  There's a number of things that 
> don't make sense here, beyond the obvious claims.

 From an earlier post of Walker's: "Many of the ideas being discussed in 
this thread are published in my Ph.D. thesis submitted in 1997 at ETH 
Zurich, Switzerland." True, id doesn't say that it's the basis of his 
degree, or even that he has one.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

Thank you for the interesting discussion, but some of you need to work on
your manners.

William


>Eric Jacobsen wrote:
>> On 3/23/2010 9:02 PM, Jerry Avins wrote:
>>> steveu wrote:
>>>
>>>> ... only one person here doesn't seem to grasp
>>>> that this ain't gonna happen.
>>>
>>> It was the subject of his thesis and he passed his defence, so it must
>>> be valid. Isn't that how it goes?
>>>
>>> Jerry
>> 
>> I'm struggling to believe that this is true.   That's a pretty sad 
>> indictment of that institution if this got by a PhD committee.
>> 
>> I suspect there's more to this story.  There's a number of things that 
>> don't make sense here, beyond the obvious claims.
>
> From an earlier post of Walker's: "Many of the ideas being discussed in 
>this thread are published in my Ph.D. thesis submitted in 1997 at ETH 
>Zurich, Switzerland." True, id doesn't say that it's the basis of his 
>degree, or even that he has one.
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

WWalker <william.walker@n_o_s_p_a_m.imtek.de> wrote:
(snip)
 
> This is not phase velocity, this is group velocity i.e. 
> time delay of the envelope.

If the system is linear, w (omega) proportional to k (wave number)
then group velocity and phase velocity are equal.  If it is slightly
non-linear then phase velocity is w/k and group velocity dw/dk.
The works as long as the higher derivatives don't become too big.
Optical materials away from resonance are pretty well described
using w/k and dw/dk.   

Now, follow the dispersion (w vs. k) curve through a resonance.  
It goes up, limited by the loss term, and then goes down, and
finally negative.  Near resonance the index of refraction can go
below 1, and even go negative.  That doesn't mean that light
travels faster than c, or backwards.  

Some years ago there was a long discussion on this, along with
the corresponding DSP terms, group delay and phase delay.

-- glen

Glen,

In a dipole system, the wave vector (k) is a function of both frequency (w)
and distance (r). This can be seen in that the wavelength (L) is larger in
the nearfield than in the farfield (k=2*Pi/L). This changes the phase speed
formula to cph=w/(k+r*dk/dr) and the group speed to cg=Dw/(Dk+r*d(Dk)/dr),
where (Dk) is the modulation wave vector and (Dw) is the modulation
frequency. Note that the formulas reduce to your formulas in the farfield,
where k is only a function of frequency. refer to p.9-10 in my paper: 
http://xxx.lanl.gov/pdf/physics/0603240

The resultant dipole system dispersion curves, and the phase speed and
group speed curves are on p.12-13 of my paper.

Note, there is not any resonance in the dipole system. It is an entirely
different type of system.

William


>WWalker <william.walker@n_o_s_p_a_m.imtek.de> wrote:
>(snip)
> 
>> This is not phase velocity, this is group velocity i.e. 
>> time delay of the envelope.
>
>If the system is linear, w (omega) proportional to k (wave number)
>then group velocity and phase velocity are equal.  If it is slightly
>non-linear then phase velocity is w/k and group velocity dw/dk.
>The works as long as the higher derivatives don't become too big.
>Optical materials away from resonance are pretty well described
>using w/k and dw/dk.   
>
>Now, follow the dispersion (w vs. k) curve through a resonance.  
>It goes up, limited by the loss term, and then goes down, and
>finally negative.  Near resonance the index of refraction can go
>below 1, and even go negative.  That doesn't mean that light
>travels faster than c, or backwards.  
>
>Some years ago there was a long discussion on this, along with
>the corresponding DSP terms, group delay and phase delay.
>
>-- glen
>

On 3/24/2010 8:04 AM, WWalker wrote:
> Eric,
>
> There is fundamental difference between a phase shift caused by a filter
> and a time delay caused by wave propagation across a region of space. The
> Op Amp filter circuit is simply phase shifting the harmonic components of
> the signal such that the overall signal appears like it has arrived before
> it was transmitted. The circuit is not really predicting the signal it is
> only phase shifting it.

Yes, this is fundamental.  Still, of note, is that the way to 
distinguish between such a phase shift and an increase in propagation 
velocity is to introduce a perturbation, as Andor did, so that it can be 
seen whether the prediction is due to negative group delay or 
accelerated propagation.   Andor's experiment is revealing in that it 
offers a method to demonstrate that what appears to be accelerated 
propagation is really narrow-band prediction.   As far as I can tell you 
have not yet done the same, and are instead claiming the rather 
grandiose explanation of virtual photons (which cannot be used in the 
context of information transfer) and propagation faster than the speed 
of light.

It could be cleared up pretty easily by demonstrating actual information 
transmission, but it seems to me that you resort to hand waving instead.

> In my system, the time delay of the signal is completely due to wave
> propagation across space. It is not a filter.

You have not yet demonstrated that.

> The simulation I presented simply shows the time delay of the modulation of
> an AM signal transmission between two nearfield dipole antennas. If you
> zoom in one can see that the modulations arrive earlier than a light
> propagated signal.

Except that with the signals you're using the propagation cannot be 
distinguished from a phase shift.   Again, the point of Andor's paper is 
that there's a simple way to distinguish the difference.   Until you do 
so you should not expect much respect of your grandiose claims when 
there's a much simpler explanation.

> This is not phase velocity, this is group velocity i.e. time delay of the
> envelope.
>
> William

It doesn't matter which it is or whether the conditions are linear so 
that they're the same, you haven't demonstrated that the propagation has 
accelerated.   Either demonstrate some actual information transmission 
or expect people to keep pushing back on you.  You have a high burden of 
proof to make the claims that you're making, but you don't seem to want 
to offer anything substantial.


>
>
>
>> On 3/23/2010 6:06 PM, WWalker wrote:
>>> Eric,
>>>
>>> Interesting article, but I don't see how it applies to my system. The
>>> system described in the paper is a bandpass filter in a feedback loop,
>>> where the bandpass filter phase function is altered by the feedback.
> The
>>> feedback forces the endpoints of the phase to zero, creating regions of
>>> possitive slope, which yield negative group delays for narrow band
> signals.
>>> This causes narrow band signals at the output of the circuit appear to
>>> arrive earlier than signals at the input of the circuit. Because the
>>> information in the signals is slightly redundant, the circuit is able
> to
>>> reconstruct future parts of the signal from the present part of the
>>> signal.
>>
>> Snipped context to allow bottom-posting.
>>
>> Feedback is not necessary to produce negative group delay.   Here's
>> another example with a passive notch filter that exhibits negative group
>> delay.
>>
>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>
>> It doesn't matter what's inside a black box if it has a negative group
>> delay characteristic if the transfer function is LTI.   Whether there's
>> feedback or not in the implementation is inconsequential.   Consider
>> that the passive notch filter could also be implemented as an active
>> circuit with feedback, and if the transfer functions are equivalent they
>> are functionally equivalent.   This is fundamental.  I don't think the
>> feedback has anything to do with it.
>>
>> You're argument on the redundancy, though, is spot-on.   Note that, as
>> others have already pointed out multiple times, the signals you're using
>> in your experiment are HIGHLY redundant, so much so that they carry
>> almost no information.   These signals are therefore not suitable for
>> proving anything about information propagation.
>>
>>
>>> First of all, this is a circuit which alters the phase function with
>>> respect to time and not space, as it is in my system. The phase function
> in
>>> the circuit is not due to wave propagaton, where mine is.
>>
>> As far as I've been able to tell, your evidence is based on a
>> simulation, in which case dimensionalities are abstractions.   You are
>> not performing anything in either time or space, you're performing a
>> numerical simulation.  Space-time transforms are not at all unusual and
>> it is likely that a substitution is easily performed.  Nothing has
>> propagated in your simulation in either time or space.
>>
>>> Secondly,unlike the circuit, my system is causal. The recieved signal in
> my
>>> system arrives after the signal is transmitted. It just travels faster
> than
>>> light.
>>
>> Uh, the circuit is causal.  That was the point.
>>
>> You have not demonstrated that your system is causal or not causal.
>> That cannot be concluded using the waveforms you show in your paper due
>> to the high determinism and narrow band characteristics.
>>
>>> Thirdly, the negative group delay in the circuit was accomplished by
> using
>>> feedback which does not exist in my system.
>>
>> As I stated above, this is inconsequential.
>>
>>
>>> Information (modulations) are clearly transmitted using narrowband AM
> radio
>>> communication, just listen to an AM radio. The simulation I presented
>>> simply shows that random AM modulations arrive undistorted across space,
> in
>>> the nearfield, earlier than a light speed propagated signal.
>>
>> Your simulation does not demonstrate that.  Turn the signal off, even at
>> a zero crossing if you want to minimize perturbations, and see what
> happens.
>>
>>> Signal purturbations can not be used to measure the signal propagation
> in
>>> the nearfield because they distort in the nearfield, and group speed has
> no
>>> meaning if the signal distorts as it propagates.
>>>
>>> William
>>
>> If you cannot use a perturbation (i.e., information transmission) to
>> measure signal propagation then you cannot demonstrate the speed of
>> information propagation.   Until you can actually demonstrate something
>> other than phase velocity (which is NOT information transmission and
>> many here have acknowledged can be faster than c, as do I), then you
>> cannot make the conclusions that you are claiming.
>>
>>
>> --
>> Eric Jacobsen
>> Minister of Algorithms
>> Abineau Communications
>> http://www.abineau.com
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

On 3/24/2010 8:04 AM, WWalker wrote:
> Eric,
>
> There is fundamental difference between a phase shift caused by a filter
> and a time delay caused by wave propagation across a region of space. The
> Op Amp filter circuit is simply phase shifting the harmonic components of
> the signal such that the overall signal appears like it has arrived before
> it was transmitted. The circuit is not really predicting the signal it is
> only phase shifting it.

Yes, this is fundamental.  Still, of note, is that the way to 
distinguish between such a phase shift and an increase in propagation 
velocity is to introduce a perturbation, as Andor did, so that it can be 
seen whether the prediction is due to negative group delay or 
accelerated propagation.   Andor's experiment is revealing in that it 
offers a method to demonstrate that what appears to be accelerated 
propagation is really narrow-band prediction.   As far as I can tell you 
have not yet done the same, and are instead claiming the rather 
grandiose explanation of virtual photons (which cannot be used in the 
context of information transfer) and propagation faster than the speed 
of light.

It could be cleared up pretty easily by demonstrating actual information 
transmission, but it seems to me that you resort to hand waving instead.

> In my system, the time delay of the signal is completely due to wave
> propagation across space. It is not a filter.

You have not yet demonstrated that.

> The simulation I presented simply shows the time delay of the modulation of
> an AM signal transmission between two nearfield dipole antennas. If you
> zoom in one can see that the modulations arrive earlier than a light
> propagated signal.

Except that with the signals you're using the propagation cannot be 
distinguished from a phase shift.   Again, the point of Andor's paper is 
that there's a simple way to distinguish the difference.   Until you do 
so you should not expect much respect of your grandiose claims when 
there's a much simpler explanation.

> This is not phase velocity, this is group velocity i.e. time delay of the
> envelope.
>
> William

It doesn't matter which it is or whether the conditions are linear so 
that they're the same, you haven't demonstrated that the propagation has 
accelerated.   Either demonstrate some actual information transmission 
or expect people to keep pushing back on you.  You have a high burden of 
proof to make the claims that you're making, but you don't seem to want 
to offer anything substantial.


>
>
>
>> On 3/23/2010 6:06 PM, WWalker wrote:
>>> Eric,
>>>
>>> Interesting article, but I don't see how it applies to my system. The
>>> system described in the paper is a bandpass filter in a feedback loop,
>>> where the bandpass filter phase function is altered by the feedback.
> The
>>> feedback forces the endpoints of the phase to zero, creating regions of
>>> possitive slope, which yield negative group delays for narrow band
> signals.
>>> This causes narrow band signals at the output of the circuit appear to
>>> arrive earlier than signals at the input of the circuit. Because the
>>> information in the signals is slightly redundant, the circuit is able
> to
>>> reconstruct future parts of the signal from the present part of the
>>> signal.
>>
>> Snipped context to allow bottom-posting.
>>
>> Feedback is not necessary to produce negative group delay.   Here's
>> another example with a passive notch filter that exhibits negative group
>> delay.
>>
>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>
>> It doesn't matter what's inside a black box if it has a negative group
>> delay characteristic if the transfer function is LTI.   Whether there's
>> feedback or not in the implementation is inconsequential.   Consider
>> that the passive notch filter could also be implemented as an active
>> circuit with feedback, and if the transfer functions are equivalent they
>> are functionally equivalent.   This is fundamental.  I don't think the
>> feedback has anything to do with it.
>>
>> You're argument on the redundancy, though, is spot-on.   Note that, as
>> others have already pointed out multiple times, the signals you're using
>> in your experiment are HIGHLY redundant, so much so that they carry
>> almost no information.   These signals are therefore not suitable for
>> proving anything about information propagation.
>>
>>
>>> First of all, this is a circuit which alters the phase function with
>>> respect to time and not space, as it is in my system. The phase function
> in
>>> the circuit is not due to wave propagaton, where mine is.
>>
>> As far as I've been able to tell, your evidence is based on a
>> simulation, in which case dimensionalities are abstractions.   You are
>> not performing anything in either time or space, you're performing a
>> numerical simulation.  Space-time transforms are not at all unusual and
>> it is likely that a substitution is easily performed.  Nothing has
>> propagated in your simulation in either time or space.
>>
>>> Secondly,unlike the circuit, my system is causal. The recieved signal in
> my
>>> system arrives after the signal is transmitted. It just travels faster
> than
>>> light.
>>
>> Uh, the circuit is causal.  That was the point.
>>
>> You have not demonstrated that your system is causal or not causal.
>> That cannot be concluded using the waveforms you show in your paper due
>> to the high determinism and narrow band characteristics.
>>
>>> Thirdly, the negative group delay in the circuit was accomplished by
> using
>>> feedback which does not exist in my system.
>>
>> As I stated above, this is inconsequential.
>>
>>
>>> Information (modulations) are clearly transmitted using narrowband AM
> radio
>>> communication, just listen to an AM radio. The simulation I presented
>>> simply shows that random AM modulations arrive undistorted across space,
> in
>>> the nearfield, earlier than a light speed propagated signal.
>>
>> Your simulation does not demonstrate that.  Turn the signal off, even at
>> a zero crossing if you want to minimize perturbations, and see what
> happens.
>>
>>> Signal purturbations can not be used to measure the signal propagation
> in
>>> the nearfield because they distort in the nearfield, and group speed has
> no
>>> meaning if the signal distorts as it propagates.
>>>
>>> William
>>
>> If you cannot use a perturbation (i.e., information transmission) to
>> measure signal propagation then you cannot demonstrate the speed of
>> information propagation.   Until you can actually demonstrate something
>> other than phase velocity (which is NOT information transmission and
>> many here have acknowledged can be faster than c, as do I), then you
>> cannot make the conclusions that you are claiming.
>>
>>
>> --
>> Eric Jacobsen
>> Minister of Algorithms
>> Abineau Communications
>> http://www.abineau.com
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric,

The dicontinuity of a pulse from a dipole source propagates at light speed,
but the pulse distorts in the nearfield because it is wideband and the
dispersion is not linear over the bandwidth of the signal. In the farfield
the pulse realigns and propagates with out distortion at the speed of
light. Group speed only has meaning if the signal does not distort as it
propagates. So in the nearfield one can not say anything about the
propagation speed of a pulse, but in the farfield the pulse clearly
propagates undistorted at the speed of light.

Only a narrowband signal propagates without distortion in both the
nearfield and farfield from a dipole source. This is because the dispersion
is not very nonlinear and can approximately linear over the bandwidth of a
narrow band signal. Since the signal does not distort as it propagates then
the group speed can be clearly observed. 

The dipole system is not a filter. Wave propagation from a dipole source
occurs in free space. There is not a medium which can filter out or change
frequency components in a signal. The transfer functions of a dipole source
simply decribes how the field components propagate. 

Clearly simple narrowband AM radio transmission contains information. Just
turn on an AM radio and listen. The information is known to be the
modulation envelope of the AM signal. My simmulation simply shows that in
the nearfield, the modulation envelope arrives earlier in time (dt) than a
light speed propagated modulation (dt=0.08/fc), where fc is the carrier
frequency.

William


>On 3/24/2010 8:04 AM, WWalker wrote:
>> Eric,
>>
>> There is fundamental difference between a phase shift caused by a
filter
>> and a time delay caused by wave propagation across a region of space.
The
>> Op Amp filter circuit is simply phase shifting the harmonic components
of
>> the signal such that the overall signal appears like it has arrived
before
>> it was transmitted. The circuit is not really predicting the signal it
is
>> only phase shifting it.
>
>Yes, this is fundamental.  Still, of note, is that the way to 
>distinguish between such a phase shift and an increase in propagation 
>velocity is to introduce a perturbation, as Andor did, so that it can be 
>seen whether the prediction is due to negative group delay or 
>accelerated propagation.   Andor's experiment is revealing in that it 
>offers a method to demonstrate that what appears to be accelerated 
>propagation is really narrow-band prediction.   As far as I can tell you 
>have not yet done the same, and are instead claiming the rather 
>grandiose explanation of virtual photons (which cannot be used in the 
>context of information transfer) and propagation faster than the speed 
>of light.
>
>It could be cleared up pretty easily by demonstrating actual information 
>transmission, but it seems to me that you resort to hand waving instead.
>
>> In my system, the time delay of the signal is completely due to wave
>> propagation across space. It is not a filter.
>
>You have not yet demonstrated that.
>
>> The simulation I presented simply shows the time delay of the modulation
of
>> an AM signal transmission between two nearfield dipole antennas. If you
>> zoom in one can see that the modulations arrive earlier than a light
>> propagated signal.
>
>Except that with the signals you're using the propagation cannot be 
>distinguished from a phase shift.   Again, the point of Andor's paper is 
>that there's a simple way to distinguish the difference.   Until you do 
>so you should not expect much respect of your grandiose claims when 
>there's a much simpler explanation.
>
>> This is not phase velocity, this is group velocity i.e. time delay of
the
>> envelope.
>>
>> William
>
>It doesn't matter which it is or whether the conditions are linear so 
>that they're the same, you haven't demonstrated that the propagation has 
>accelerated.   Either demonstrate some actual information transmission 
>or expect people to keep pushing back on you.  You have a high burden of 
>proof to make the claims that you're making, but you don't seem to want 
>to offer anything substantial.
>
>
>>
>>
>>
>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>> Eric,
>>>>
>>>> Interesting article, but I don't see how it applies to my system. The
>>>> system described in the paper is a bandpass filter in a feedback
loop,
>>>> where the bandpass filter phase function is altered by the feedback.
>> The
>>>> feedback forces the endpoints of the phase to zero, creating regions
of
>>>> possitive slope, which yield negative group delays for narrow band
>> signals.
>>>> This causes narrow band signals at the output of the circuit appear
to
>>>> arrive earlier than signals at the input of the circuit. Because the
>>>> information in the signals is slightly redundant, the circuit is able
>> to
>>>> reconstruct future parts of the signal from the present part of the
>>>> signal.
>>>
>>> Snipped context to allow bottom-posting.
>>>
>>> Feedback is not necessary to produce negative group delay.   Here's
>>> another example with a passive notch filter that exhibits negative
group
>>> delay.
>>>
>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>
>>> It doesn't matter what's inside a black box if it has a negative group
>>> delay characteristic if the transfer function is LTI.   Whether
there's
>>> feedback or not in the implementation is inconsequential.   Consider
>>> that the passive notch filter could also be implemented as an active
>>> circuit with feedback, and if the transfer functions are equivalent
they
>>> are functionally equivalent.   This is fundamental.  I don't think the
>>> feedback has anything to do with it.
>>>
>>> You're argument on the redundancy, though, is spot-on.   Note that, as
>>> others have already pointed out multiple times, the signals you're
using
>>> in your experiment are HIGHLY redundant, so much so that they carry
>>> almost no information.   These signals are therefore not suitable for
>>> proving anything about information propagation.
>>>
>>>
>>>> First of all, this is a circuit which alters the phase function with
>>>> respect to time and not space, as it is in my system. The phase
function
>> in
>>>> the circuit is not due to wave propagaton, where mine is.
>>>
>>> As far as I've been able to tell, your evidence is based on a
>>> simulation, in which case dimensionalities are abstractions.   You are
>>> not performing anything in either time or space, you're performing a
>>> numerical simulation.  Space-time transforms are not at all unusual
and
>>> it is likely that a substitution is easily performed.  Nothing has
>>> propagated in your simulation in either time or space.
>>>
>>>> Secondly,unlike the circuit, my system is causal. The recieved signal
in
>> my
>>>> system arrives after the signal is transmitted. It just travels
faster
>> than
>>>> light.
>>>
>>> Uh, the circuit is causal.  That was the point.
>>>
>>> You have not demonstrated that your system is causal or not causal.
>>> That cannot be concluded using the waveforms you show in your paper
due
>>> to the high determinism and narrow band characteristics.
>>>
>>>> Thirdly, the negative group delay in the circuit was accomplished by
>> using
>>>> feedback which does not exist in my system.
>>>
>>> As I stated above, this is inconsequential.
>>>
>>>
>>>> Information (modulations) are clearly transmitted using narrowband AM
>> radio
>>>> communication, just listen to an AM radio. The simulation I presented
>>>> simply shows that random AM modulations arrive undistorted across
space,
>> in
>>>> the nearfield, earlier than a light speed propagated signal.
>>>
>>> Your simulation does not demonstrate that.  Turn the signal off, even
at
>>> a zero crossing if you want to minimize perturbations, and see what
>> happens.
>>>
>>>> Signal purturbations can not be used to measure the signal
propagation
>> in
>>>> the nearfield because they distort in the nearfield, and group speed
has
>> no
>>>> meaning if the signal distorts as it propagates.
>>>>
>>>> William
>>>
>>> If you cannot use a perturbation (i.e., information transmission) to
>>> measure signal propagation then you cannot demonstrate the speed of
>>> information propagation.   Until you can actually demonstrate
something
>>> other than phase velocity (which is NOT information transmission and
>>> many here have acknowledged can be faster than c, as do I), then you
>>> cannot make the conclusions that you are claiming.
>>>
>>>
>>> --
>>> Eric Jacobsen
>>> Minister of Algorithms
>>> Abineau Communications
>>> http://www.abineau.com
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 3/24/2010 4:56 PM, WWalker wrote:
> Eric,
>
> The dicontinuity of a pulse from a dipole source propagates at light speed,
> but the pulse distorts in the nearfield because it is wideband and the
> dispersion is not linear over the bandwidth of the signal. In the farfield
> the pulse realigns and propagates with out distortion at the speed of
> light. Group speed only has meaning if the signal does not distort as it
> propagates. So in the nearfield one can not say anything about the
> propagation speed of a pulse, but in the farfield the pulse clearly
> propagates undistorted at the speed of light.

In previous posts you seemed to be claiming that the signal was 
propagating faster than c in the near field.   Now you are saying "in 
the nearfield one can not say anything about the propagation speed of a 
pulse".  Can you clear up my confusion?   Are you claiming that there is 
a region over which the signal propagates at a speed faster than c?

> Only a narrowband signal propagates without distortion in both the
> nearfield and farfield from a dipole source. This is because the dispersion
> is not very nonlinear and can approximately linear over the bandwidth of a
> narrow band signal. Since the signal does not distort as it propagates then
> the group speed can be clearly observed.

> The dipole system is not a filter. Wave propagation from a dipole source
> occurs in free space. There is not a medium which can filter out or change
> frequency components in a signal. The transfer functions of a dipole source
> simply decribes how the field components propagate.

Dipoles are actually bandpass filters with a center frequency determined 
by the length of the dipole as related to the wavelength of the carrier. 
   Efficiency drops off significantly as the wavelength changes 
substantially from the resonant length of the dipole.

> Clearly simple narrowband AM radio transmission contains information. Just
> turn on an AM radio and listen. The information is known to be the
> modulation envelope of the AM signal. My simmulation simply shows that in
> the nearfield, the modulation envelope arrives earlier in time (dt) than a
> light speed propagated modulation (dt=0.08/fc), where fc is the carrier
> frequency.

You seem to be unclear on the definition of "information" in this 
context, and I think it's a big part of what's tripping you up.  The AM 
radio broadcast signals you like to cite contain "information" because 
they're modulated with a significant degree of random components.   As 
has been pointed out previously, you may not have an adequate grasp on 
what "random" means in this context, either.   So not getting 
"information" and "random" right in this context may be the root of 
what's led you astray.

I shall point out again, as have others, that if you introduce some 
genuine randomness (i.e., information) into your test signals you will 
be able to demonstrate whether your claims of propagation faster than c 
are true (if you are, in fact, still claiming that) or not.  Until then 
I will again point out that your current test signals are NOT adequate 
for that purpose.   Jerry pointed out long ago that your signals are 
completely deterministic, and, therefore, not random.   Anybody with the 
most basic knowledge of trigonometry can predict the exact value of the 
signal at ANY point in the future given the initial parameters.  In 
fact, your simulation can do that, too!  And it is!  That proves 
absolutely nothing and does not support the claims that you have been 
making of propagation faster than the speed of light.

The same can not be said of a typical AM radio broadcast signal because 
those do, in fact, have random components due to the changing nature of 
the modulating signals.   The parameters of your modulating signals, the 
amplitudes and relative phases of the initial input sinusoids, do not 
change and therefore carry no information beyond those initial 
parameters.  This means that a short window of observation is all that 
is needed to extract what little information there is in the signal, 
because there isn't any additional information added beyond that. 
After that, no information is carried in the signal other than "no 
change", and there certainly aren't any random components by which to 
measure information propagation.

A static '1' has minimal information, and observing it's state past 
reliable detection of the initial transition into that state will reveal 
no additional information by which propagation speed can be measured. 
This is the case with your test signals as well.  The relative phases of 
the signals are NOT indicative of propagation velocity.  You need to add 
a perturbation of some sort, i.e., new modulating information, and 
detect the propagation velocity of that new modulated information. 
Until you do that it appears to me that you have no basis on which to 
make claims of any unexpected phenomena.



>
> William
>
>
>> On 3/24/2010 8:04 AM, WWalker wrote:
>>> Eric,
>>>
>>> There is fundamental difference between a phase shift caused by a
> filter
>>> and a time delay caused by wave propagation across a region of space.
> The
>>> Op Amp filter circuit is simply phase shifting the harmonic components
> of
>>> the signal such that the overall signal appears like it has arrived
> before
>>> it was transmitted. The circuit is not really predicting the signal it
> is
>>> only phase shifting it.
>>
>> Yes, this is fundamental.  Still, of note, is that the way to
>> distinguish between such a phase shift and an increase in propagation
>> velocity is to introduce a perturbation, as Andor did, so that it can be
>> seen whether the prediction is due to negative group delay or
>> accelerated propagation.   Andor's experiment is revealing in that it
>> offers a method to demonstrate that what appears to be accelerated
>> propagation is really narrow-band prediction.   As far as I can tell you
>> have not yet done the same, and are instead claiming the rather
>> grandiose explanation of virtual photons (which cannot be used in the
>> context of information transfer) and propagation faster than the speed
>> of light.
>>
>> It could be cleared up pretty easily by demonstrating actual information
>> transmission, but it seems to me that you resort to hand waving instead.
>>
>>> In my system, the time delay of the signal is completely due to wave
>>> propagation across space. It is not a filter.
>>
>> You have not yet demonstrated that.
>>
>>> The simulation I presented simply shows the time delay of the modulation
> of
>>> an AM signal transmission between two nearfield dipole antennas. If you
>>> zoom in one can see that the modulations arrive earlier than a light
>>> propagated signal.
>>
>> Except that with the signals you're using the propagation cannot be
>> distinguished from a phase shift.   Again, the point of Andor's paper is
>> that there's a simple way to distinguish the difference.   Until you do
>> so you should not expect much respect of your grandiose claims when
>> there's a much simpler explanation.
>>
>>> This is not phase velocity, this is group velocity i.e. time delay of
> the
>>> envelope.
>>>
>>> William
>>
>> It doesn't matter which it is or whether the conditions are linear so
>> that they're the same, you haven't demonstrated that the propagation has
>> accelerated.   Either demonstrate some actual information transmission
>> or expect people to keep pushing back on you.  You have a high burden of
>> proof to make the claims that you're making, but you don't seem to want
>> to offer anything substantial.
>>
>>
>>>
>>>
>>>
>>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>>> Eric,
>>>>>
>>>>> Interesting article, but I don't see how it applies to my system. The
>>>>> system described in the paper is a bandpass filter in a feedback
> loop,
>>>>> where the bandpass filter phase function is altered by the feedback.
>>> The
>>>>> feedback forces the endpoints of the phase to zero, creating regions
> of
>>>>> possitive slope, which yield negative group delays for narrow band
>>> signals.
>>>>> This causes narrow band signals at the output of the circuit appear
> to
>>>>> arrive earlier than signals at the input of the circuit. Because the
>>>>> information in the signals is slightly redundant, the circuit is able
>>> to
>>>>> reconstruct future parts of the signal from the present part of the
>>>>> signal.
>>>>
>>>> Snipped context to allow bottom-posting.
>>>>
>>>> Feedback is not necessary to produce negative group delay.   Here's
>>>> another example with a passive notch filter that exhibits negative
> group
>>>> delay.
>>>>
>>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>>
>>>> It doesn't matter what's inside a black box if it has a negative group
>>>> delay characteristic if the transfer function is LTI.   Whether
> there's
>>>> feedback or not in the implementation is inconsequential.   Consider
>>>> that the passive notch filter could also be implemented as an active
>>>> circuit with feedback, and if the transfer functions are equivalent
> they
>>>> are functionally equivalent.   This is fundamental.  I don't think the
>>>> feedback has anything to do with it.
>>>>
>>>> You're argument on the redundancy, though, is spot-on.   Note that, as
>>>> others have already pointed out multiple times, the signals you're
> using
>>>> in your experiment are HIGHLY redundant, so much so that they carry
>>>> almost no information.   These signals are therefore not suitable for
>>>> proving anything about information propagation.
>>>>
>>>>
>>>>> First of all, this is a circuit which alters the phase function with
>>>>> respect to time and not space, as it is in my system. The phase
> function
>>> in
>>>>> the circuit is not due to wave propagaton, where mine is.
>>>>
>>>> As far as I've been able to tell, your evidence is based on a
>>>> simulation, in which case dimensionalities are abstractions.   You are
>>>> not performing anything in either time or space, you're performing a
>>>> numerical simulation.  Space-time transforms are not at all unusual
> and
>>>> it is likely that a substitution is easily performed.  Nothing has
>>>> propagated in your simulation in either time or space.
>>>>
>>>>> Secondly,unlike the circuit, my system is causal. The recieved signal
> in
>>> my
>>>>> system arrives after the signal is transmitted. It just travels
> faster
>>> than
>>>>> light.
>>>>
>>>> Uh, the circuit is causal.  That was the point.
>>>>
>>>> You have not demonstrated that your system is causal or not causal.
>>>> That cannot be concluded using the waveforms you show in your paper
> due
>>>> to the high determinism and narrow band characteristics.
>>>>
>>>>> Thirdly, the negative group delay in the circuit was accomplished by
>>> using
>>>>> feedback which does not exist in my system.
>>>>
>>>> As I stated above, this is inconsequential.
>>>>
>>>>
>>>>> Information (modulations) are clearly transmitted using narrowband AM
>>> radio
>>>>> communication, just listen to an AM radio. The simulation I presented
>>>>> simply shows that random AM modulations arrive undistorted across
> space,
>>> in
>>>>> the nearfield, earlier than a light speed propagated signal.
>>>>
>>>> Your simulation does not demonstrate that.  Turn the signal off, even
> at
>>>> a zero crossing if you want to minimize perturbations, and see what
>>> happens.
>>>>
>>>>> Signal purturbations can not be used to measure the signal
> propagation
>>> in
>>>>> the nearfield because they distort in the nearfield, and group speed
> has
>>> no
>>>>> meaning if the signal distorts as it propagates.
>>>>>
>>>>> William
>>>>
>>>> If you cannot use a perturbation (i.e., information transmission) to
>>>> measure signal propagation then you cannot demonstrate the speed of
>>>> information propagation.   Until you can actually demonstrate
> something
>>>> other than phase velocity (which is NOT information transmission and
>>>> many here have acknowledged can be faster than c, as do I), then you
>>>> cannot make the conclusions that you are claiming.
>>>>
>>>>
>>>> --
>>>> Eric Jacobsen
>>>> Minister of Algorithms
>>>> Abineau Communications
>>>> http://www.abineau.com
>>>>
>>
>>
>> --
>> Eric Jacobsen
>> Minister of Algorithms
>> Abineau Communications
>> http://www.abineau.com
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric Jacobsen wrote:

   ...

> You seem to be unclear on the definition of "information" in this 
> context, and I think it's a big part of what's tripping you up.  The AM 
> radio broadcast signals you like to cite contain "information" because 
> they're modulated with a significant degree of random components.   As 
> has been pointed out previously, you may not have an adequate grasp on 
> what "random" means in this context, either.   So not getting 
> "information" and "random" right in this context may be the root of 
> what's led you astray.

Some people fail to distinguish between "random" and "arbitrarily 
chosen". That can lead to astonishing errors of analysis.

   ...


Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

>The dipole system is not a filter.

Huh? A dipole is tuned by its length. It is *very* much a filter.

>Wave propagation from a dipole source
>occurs in free space. There is not a medium which can filter out or
change
>frequency components in a signal. The transfer functions of a dipole
source
>simply decribes how the field components propagate. 

>Clearly simple narrowband AM radio transmission contains information.
Just
>turn on an AM radio and listen. The information is known to be the
>modulation envelope of the AM signal. My simulation simply shows that in
>the nearfield, the modulation envelope arrives earlier in time (dt) than
a
>light speed propagated modulation (dt=0.08/fc), where fc is the carrier
>frequency.

You seem to be struggling with the nature of the word information. By
definition, information is that which is not predictable. A substantial
part of the output of an AM receiver is very much predictable, from the
history of the received signal and knowledge of the precise characteristics
of the channel (essentially its bandwidth, and phase characteristics).
Showing something comes out early doesn't show anything interesting. To be
carrying information faster than light it has to be something
*unpredictable* which comes out early.

So far you seem to have made no attempt to show that any unpredictable
content can pass through your model, and arrive faster than light. In fact
you have made some vague comments that unpredictable things mess up your
model. Maybe that should be telling you something.

Steve

Eric Jacobsen wrote:

   ...

> Dipoles are actually bandpass filters with a center frequency determined 
> by the length of the dipole as related to the wavelength of the carrier. 
>   Efficiency drops off significantly as the wavelength changes 
> substantially from the resonant length of the dipole.

Herein lies the fallacy that is at the heart of what I see as self 
deception. Eric describes a real dipole, while Walter's simulation is 
constructed around an ideal one. An ideal dipole is a limit as the 
length of a real dipole goes to zero while the power it radiates remains 
constant. (Compare to an impulse: a pulse whose width goes to zero while 
its area remains constant.) Such abstractions are useful for brushing 
aside irrelevant details while retaining relevant relationships. They 
remain useful only so long as the ignored details remain irrelevant. For 
example, it is inappropriate to inquire about the voltage gradient along 
an ideal diode.

An example might clarify the limit of an abstraction's utility. Consider 
a ball bouncing on a flat surface, such that every bounce's duration is 
90% of that of the previous bounce. The ball is initially dropped from 
such a height that the first bounce lasts exactly one second. It is not 
difficult to show that the ball will come to rest after ten seconds. In 
that interval, how many times will the ball bounce?

In dipoles, the extents of the near field are related to the dimensions 
of the dipole. We can expect an ideal dipole, having zero length, to 
have a very peculiar calculated near field.

   ...

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

William wrote:
>The dipole system is not a filter. 

Are you sure?  Lots of things can be viewed as filters, even if that's not
how we traditionally think of them.


>Wave propagation from a dipole source
>occurs in free space. There is not a medium which can filter out or
change
>frequency components in a signal. The transfer functions of a dipole
source
>simply decribes how the field components propagate. 

A filter doesn't need to "filter out" components.  Even a time delay can be
modeled as a filter.  Pick a point, and explain how the field at that point
is a function of the driving signal.

Moreover, if you didn't at least consider the possibility of treating it as
a filter in SOME sense, why would you have posted to this group?  (Not that
it's wrong to do so, but my point is I think you did suspect as much.)

Michael

Eric,

A narrow band AM signal propagates undistorted and faster than light in the
nearfield and reduces to the speed of light as it goes into the farfield. A
pulse distorts in the nearfield and and realigns as it goes into the
farfield. When the pulse is distorted, one cannot say anything about the
speed of the pulse. To transmit information faster than light one must use
narrowband signals like AM and transmitt and receive them in the nearfield
of the carrier.

It is true that a real dipole anntena has filter characteristics. The
simulation I presented is an idealized dipole like an oscillating electron
which does not have filter characteristics. In an experiment with real
antennas one would have to subtract out the phase shifts due to the
antennas filter characteristics so that one only sees the time delay
behavior of the propagating fields.  

The signals I used in my simulation are a changing modulation over the time
window of analysis. The changing modulation does not repeat over this
window. It is true that they are created from deterministic signals.
Bassically I generated a beat frequency modulation which has a carrier and
a modulation frequency. Provided the window of analysis is smaller than a
modulation time period, the modulation pattern does not repeat. After a
modulation period the patern repeats again. I chose this type of signal
because it is a changing pattern which eventually repeats, enabling me to
trigger it in a real experient and also enabling me to do time averaging
which will help a lot with improving the SNR if a experimental signal.

When perform an autocorrelation of the modulation I used in my simulation,
I see a triangular signal with a peak at the time of the analysis time
window, indicating that the signal has no obserable repetition pattern of
the this time. Only after I increase the analysis time window greater than
the modulation period do I get significant sidelobes in the autocorrelation
signal, indicating that the pattern repeats after each multiple of a
modulation cycle.

Of course I can create a random narrowband signal as was done in the OpAmp
resonator paper: http://www.dsprelated.com/showarticle/54.php
modulate it with a carrier and pass it through a dipole system, and finally
extract the modulation, and compare it to a light propagated signal. If
this is done you get exactly the same answer as I showed in my simulation.
But if this technique is used than I can not use time averagiing to improve
SNR which is need for detection of the modulation in real experimental
signals. I have perfomed this random modulation simulation using Agilent
Vee Pro software which is not possible to show here in text format. But I
can try to describe it. I took a 100V random generator and sent the signal
through a 50 MHz cutoff (fc), 6th order LPF with the following transfer
function [1/(j(f/fc)+1)^6]. Then I multiplied it with a 500MHz carrier and
sent it though a light speed propagating transfer function [e^(ikr)] and
though the magnetic component of a electric dipole transfer function
[e^(ikr)*(-kr-i)]. Finally I extracted the modulation envelopes of the
tranmitted signal, light speed signal, and the dipole signal. To extract
the envelopes I used squared the signal and then passed it through a 300MHz
cutoff (fc), 12th order LPF with the following transfer function
[1/(j(f/fc)+1)^12].

William


>On 3/24/2010 4:56 PM, WWalker wrote:
>> Eric,
>>
>> The dicontinuity of a pulse from a dipole source propagates at light
speed,
>> but the pulse distorts in the nearfield because it is wideband and the
>> dispersion is not linear over the bandwidth of the signal. In the
farfield
>> the pulse realigns and propagates with out distortion at the speed of
>> light. Group speed only has meaning if the signal does not distort as
it
>> propagates. So in the nearfield one can not say anything about the
>> propagation speed of a pulse, but in the farfield the pulse clearly
>> propagates undistorted at the speed of light.
>
>In previous posts you seemed to be claiming that the signal was 
>propagating faster than c in the near field.   Now you are saying "in 
>the nearfield one can not say anything about the propagation speed of a 
>pulse".  Can you clear up my confusion?   Are you claiming that there is 
>a region over which the signal propagates at a speed faster than c?
>
>> Only a narrowband signal propagates without distortion in both the
>> nearfield and farfield from a dipole source. This is because the
dispersion
>> is not very nonlinear and can approximately linear over the bandwidth of
a
>> narrow band signal. Since the signal does not distort as it propagates
then
>> the group speed can be clearly observed.
>
>> The dipole system is not a filter. Wave propagation from a dipole
source
>> occurs in free space. There is not a medium which can filter out or
change
>> frequency components in a signal. The transfer functions of a dipole
source
>> simply decribes how the field components propagate.
>
>Dipoles are actually bandpass filters with a center frequency determined 
>by the length of the dipole as related to the wavelength of the carrier. 
>   Efficiency drops off significantly as the wavelength changes 
>substantially from the resonant length of the dipole.
>
>> Clearly simple narrowband AM radio transmission contains information.
Just
>> turn on an AM radio and listen. The information is known to be the
>> modulation envelope of the AM signal. My simmulation simply shows that
in
>> the nearfield, the modulation envelope arrives earlier in time (dt) than
a
>> light speed propagated modulation (dt=0.08/fc), where fc is the carrier
>> frequency.
>
>You seem to be unclear on the definition of "information" in this 
>context, and I think it's a big part of what's tripping you up.  The AM 
>radio broadcast signals you like to cite contain "information" because 
>they're modulated with a significant degree of random components.   As 
>has been pointed out previously, you may not have an adequate grasp on 
>what "random" means in this context, either.   So not getting 
>"information" and "random" right in this context may be the root of 
>what's led you astray.
>
>I shall point out again, as have others, that if you introduce some 
>genuine randomness (i.e., information) into your test signals you will 
>be able to demonstrate whether your claims of propagation faster than c 
>are true (if you are, in fact, still claiming that) or not.  Until then 
>I will again point out that your current test signals are NOT adequate 
>for that purpose.   Jerry pointed out long ago that your signals are 
>completely deterministic, and, therefore, not random.   Anybody with the 
>most basic knowledge of trigonometry can predict the exact value of the 
>signal at ANY point in the future given the initial parameters.  In 
>fact, your simulation can do that, too!  And it is!  That proves 
>absolutely nothing and does not support the claims that you have been 
>making of propagation faster than the speed of light.
>
>The same can not be said of a typical AM radio broadcast signal because 
>those do, in fact, have random components due to the changing nature of 
>the modulating signals.   The parameters of your modulating signals, the 
>amplitudes and relative phases of the initial input sinusoids, do not 
>change and therefore carry no information beyond those initial 
>parameters.  This means that a short window of observation is all that 
>is needed to extract what little information there is in the signal, 
>because there isn't any additional information added beyond that. 
>After that, no information is carried in the signal other than "no 
>change", and there certainly aren't any random components by which to 
>measure information propagation.
>
>A static '1' has minimal information, and observing it's state past 
>reliable detection of the initial transition into that state will reveal 
>no additional information by which propagation speed can be measured. 
>This is the case with your test signals as well.  The relative phases of 
>the signals are NOT indicative of propagation velocity.  You need to add 
>a perturbation of some sort, i.e., new modulating information, and 
>detect the propagation velocity of that new modulated information. 
>Until you do that it appears to me that you have no basis on which to 
>make claims of any unexpected phenomena.
>
>
>
>>
>> William
>>
>>
>>> On 3/24/2010 8:04 AM, WWalker wrote:
>>>> Eric,
>>>>
>>>> There is fundamental difference between a phase shift caused by a
>> filter
>>>> and a time delay caused by wave propagation across a region of space.
>> The
>>>> Op Amp filter circuit is simply phase shifting the harmonic
components
>> of
>>>> the signal such that the overall signal appears like it has arrived
>> before
>>>> it was transmitted. The circuit is not really predicting the signal
it
>> is
>>>> only phase shifting it.
>>>
>>> Yes, this is fundamental.  Still, of note, is that the way to
>>> distinguish between such a phase shift and an increase in propagation
>>> velocity is to introduce a perturbation, as Andor did, so that it can
be
>>> seen whether the prediction is due to negative group delay or
>>> accelerated propagation.   Andor's experiment is revealing in that it
>>> offers a method to demonstrate that what appears to be accelerated
>>> propagation is really narrow-band prediction.   As far as I can tell
you
>>> have not yet done the same, and are instead claiming the rather
>>> grandiose explanation of virtual photons (which cannot be used in the
>>> context of information transfer) and propagation faster than the speed
>>> of light.
>>>
>>> It could be cleared up pretty easily by demonstrating actual
information
>>> transmission, but it seems to me that you resort to hand waving
instead.
>>>
>>>> In my system, the time delay of the signal is completely due to wave
>>>> propagation across space. It is not a filter.
>>>
>>> You have not yet demonstrated that.
>>>
>>>> The simulation I presented simply shows the time delay of the
modulation
>> of
>>>> an AM signal transmission between two nearfield dipole antennas. If
you
>>>> zoom in one can see that the modulations arrive earlier than a light
>>>> propagated signal.
>>>
>>> Except that with the signals you're using the propagation cannot be
>>> distinguished from a phase shift.   Again, the point of Andor's paper
is
>>> that there's a simple way to distinguish the difference.   Until you
do
>>> so you should not expect much respect of your grandiose claims when
>>> there's a much simpler explanation.
>>>
>>>> This is not phase velocity, this is group velocity i.e. time delay of
>> the
>>>> envelope.
>>>>
>>>> William
>>>
>>> It doesn't matter which it is or whether the conditions are linear so
>>> that they're the same, you haven't demonstrated that the propagation
has
>>> accelerated.   Either demonstrate some actual information transmission
>>> or expect people to keep pushing back on you.  You have a high burden
of
>>> proof to make the claims that you're making, but you don't seem to
want
>>> to offer anything substantial.
>>>
>>>
>>>>
>>>>
>>>>
>>>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>>>> Eric,
>>>>>>
>>>>>> Interesting article, but I don't see how it applies to my system.
The
>>>>>> system described in the paper is a bandpass filter in a feedback
>> loop,
>>>>>> where the bandpass filter phase function is altered by the
feedback.
>>>> The
>>>>>> feedback forces the endpoints of the phase to zero, creating
regions
>> of
>>>>>> possitive slope, which yield negative group delays for narrow band
>>>> signals.
>>>>>> This causes narrow band signals at the output of the circuit appear
>> to
>>>>>> arrive earlier than signals at the input of the circuit. Because
the
>>>>>> information in the signals is slightly redundant, the circuit is
able
>>>> to
>>>>>> reconstruct future parts of the signal from the present part of the
>>>>>> signal.
>>>>>
>>>>> Snipped context to allow bottom-posting.
>>>>>
>>>>> Feedback is not necessary to produce negative group delay.   Here's
>>>>> another example with a passive notch filter that exhibits negative
>> group
>>>>> delay.
>>>>>
>>>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>>>
>>>>> It doesn't matter what's inside a black box if it has a negative
group
>>>>> delay characteristic if the transfer function is LTI.   Whether
>> there's
>>>>> feedback or not in the implementation is inconsequential.   Consider
>>>>> that the passive notch filter could also be implemented as an active
>>>>> circuit with feedback, and if the transfer functions are equivalent
>> they
>>>>> are functionally equivalent.   This is fundamental.  I don't think
the
>>>>> feedback has anything to do with it.
>>>>>
>>>>> You're argument on the redundancy, though, is spot-on.   Note that,
as
>>>>> others have already pointed out multiple times, the signals you're
>> using
>>>>> in your experiment are HIGHLY redundant, so much so that they carry
>>>>> almost no information.   These signals are therefore not suitable
for
>>>>> proving anything about information propagation.
>>>>>
>>>>>
>>>>>> First of all, this is a circuit which alters the phase function
with
>>>>>> respect to time and not space, as it is in my system. The phase
>> function
>>>> in
>>>>>> the circuit is not due to wave propagaton, where mine is.
>>>>>
>>>>> As far as I've been able to tell, your evidence is based on a
>>>>> simulation, in which case dimensionalities are abstractions.   You
are
>>>>> not performing anything in either time or space, you're performing a
>>>>> numerical simulation.  Space-time transforms are not at all unusual
>> and
>>>>> it is likely that a substitution is easily performed.  Nothing has
>>>>> propagated in your simulation in either time or space.
>>>>>
>>>>>> Secondly,unlike the circuit, my system is causal. The recieved
signal
>> in
>>>> my
>>>>>> system arrives after the signal is transmitted. It just travels
>> faster
>>>> than
>>>>>> light.
>>>>>
>>>>> Uh, the circuit is causal.  That was the point.
>>>>>
>>>>> You have not demonstrated that your system is causal or not causal.
>>>>> That cannot be concluded using the waveforms you show in your paper
>> due
>>>>> to the high determinism and narrow band characteristics.
>>>>>
>>>>>> Thirdly, the negative group delay in the circuit was accomplished
by
>>>> using
>>>>>> feedback which does not exist in my system.
>>>>>
>>>>> As I stated above, this is inconsequential.
>>>>>
>>>>>
>>>>>> Information (modulations) are clearly transmitted using narrowband
AM
>>>> radio
>>>>>> communication, just listen to an AM radio. The simulation I
presented
>>>>>> simply shows that random AM modulations arrive undistorted across
>> space,
>>>> in
>>>>>> the nearfield, earlier than a light speed propagated signal.
>>>>>
>>>>> Your simulation does not demonstrate that.  Turn the signal off,
even
>> at
>>>>> a zero crossing if you want to minimize perturbations, and see what
>>>> happens.
>>>>>
>>>>>> Signal purturbations can not be used to measure the signal
>> propagation
>>>> in
>>>>>> the nearfield because they distort in the nearfield, and group
speed
>> has
>>>> no
>>>>>> meaning if the signal distorts as it propagates.
>>>>>>
>>>>>> William
>>>>>
>>>>> If you cannot use a perturbation (i.e., information transmission) to
>>>>> measure signal propagation then you cannot demonstrate the speed of
>>>>> information propagation.   Until you can actually demonstrate
>> something
>>>>> other than phase velocity (which is NOT information transmission and
>>>>> many here have acknowledged can be faster than c, as do I), then you
>>>>> cannot make the conclusions that you are claiming.
>>>>>
>>>>>
>>>>> --
>>>>> Eric Jacobsen
>>>>> Minister of Algorithms
>>>>> Abineau Communications
>>>>> http://www.abineau.com
>>>>>
>>>
>>>
>>> --
>>> Eric Jacobsen
>>> Minister of Algorithms
>>> Abineau Communications
>>> http://www.abineau.com
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Jerry,

I have tested real dipole antennas using a RF Network analyser and after
compensating for the electrical filter characteristics of the antenna, I
get the nonlinear dispersion curves shown in my paper. The nonlinear
dispersion is a real observable and measureable phenomina. 

Here is another paper that presents an NEC RF numerical analysis on a
dipole and shows the nonlinear nearfield dispersion is real and
observable:
http://ceta.mit.edu/pier/pier.php?paper=0505121

William

>Eric Jacobsen wrote:
>
>   ...
>
>> Dipoles are actually bandpass filters with a center frequency determined

>> by the length of the dipole as related to the wavelength of the carrier.

>>   Efficiency drops off significantly as the wavelength changes 
>> substantially from the resonant length of the dipole.
>
>Herein lies the fallacy that is at the heart of what I see as self 
>deception. Eric describes a real dipole, while Walter's simulation is 
>constructed around an ideal one. An ideal dipole is a limit as the 
>length of a real dipole goes to zero while the power it radiates remains 
>constant. (Compare to an impulse: a pulse whose width goes to zero while 
>its area remains constant.) Such abstractions are useful for brushing 
>aside irrelevant details while retaining relevant relationships. They 
>remain useful only so long as the ignored details remain irrelevant. For 
>example, it is inappropriate to inquire about the voltage gradient along 
>an ideal diode.
>
>An example might clarify the limit of an abstraction's utility. Consider 
>a ball bouncing on a flat surface, such that every bounce's duration is 
>90% of that of the previous bounce. The ball is initially dropped from 
>such a height that the first bounce lasts exactly one second. It is not 
>difficult to show that the ball will come to rest after ten seconds. In 
>that interval, how many times will the ball bounce?
>
>In dipoles, the extents of the near field are related to the dimensions 
>of the dipole. We can expect an ideal dipole, having zero length, to 
>have a very peculiar calculated near field.
>
>   ...
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

WWalker wrote:
> Jerry,
> 
> I have tested real dipole antennas using a RF Network analyser and after
> compensating for the electrical filter characteristics of the antenna, I
> get the nonlinear dispersion curves shown in my paper. The nonlinear
> dispersion is a real observable and measureable phenomina. 

I believe that. I'm not sure what you mean by nonlinear dispersion, but 
I can guess. Dispersion is the dependence of velocity on frequency. A 
assume that with nonlinear dispersion, the dependence relationship 
departs markedly from a straight line. All the cases I know of apparent 
superluminal energy velocities arise from instances of anomalous 
dispersion. Upon analysis, all turn out to be apparent only.

> Here is another paper that presents an NEC RF numerical analysis on a
> dipole and shows the nonlinear nearfield dispersion is real and
> observable:
> http://ceta.mit.edu/pier/pier.php?paper=0505121

Thank you. Tha abstract is interesting. I will read the gull paper when 
there is more time. The title of reference 2 is noteworthy. it is "Wave 
propagation faster than light," not "Information propagation faster than 
light." There's a big difference.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 3/25/2010 8:45 AM, WWalker wrote:
> Eric,
>
> A narrow band AM signal propagates undistorted and faster than light in the
> nearfield and reduces to the speed of light as it goes into the farfield. A
> pulse distorts in the nearfield and and realigns as it goes into the
> farfield. When the pulse is distorted, one cannot say anything about the
> speed of the pulse. To transmit information faster than light one must use
> narrowband signals like AM and transmitt and receive them in the nearfield
> of the carrier.
>
> It is true that a real dipole anntena has filter characteristics. The
> simulation I presented is an idealized dipole like an oscillating electron
> which does not have filter characteristics. In an experiment with real
> antennas one would have to subtract out the phase shifts due to the
> antennas filter characteristics so that one only sees the time delay
> behavior of the propagating fields.
>
> The signals I used in my simulation are a changing modulation over the time
> window of analysis. The changing modulation does not repeat over this
> window. It is true that they are created from deterministic signals.
> Bassically I generated a beat frequency modulation which has a carrier and
> a modulation frequency. Provided the window of analysis is smaller than a
> modulation time period, the modulation pattern does not repeat. After a
> modulation period the patern repeats again. I chose this type of signal
> because it is a changing pattern which eventually repeats, enabling me to
> trigger it in a real experient and also enabling me to do time averaging
> which will help a lot with improving the SNR if a experimental signal.

The period of the signal isn't necessarily consequential, the fact that 
it is not random is.  The point being that the signal you are using is 
not suitable for measuring propagation at the resolution you're 
interested in because it is a deterministic signal.   Even when there's 
a component that is randomly changing with time it is easy to get fooled 
by the nature of narrowband signals, and that was pretty much a big 
point of Andor's paper.  I'm beginning to see why he chose the title 
that he did.

> When perform an autocorrelation of the modulation I used in my simulation,
> I see a triangular signal with a peak at the time of the analysis time
> window, indicating that the signal has no obserable repetition pattern of
> the this time. Only after I increase the analysis time window greater than
> the modulation period do I get significant sidelobes in the autocorrelation
> signal, indicating that the pattern repeats after each multiple of a
> modulation cycle.

Again, how many periods you observe isn't what matters when the signal 
is completely deterministic.  You're just observing the same, 
informationally-static signal over different periods of time.  That 
tells you little to nothing about the propagation of information.


> Of course I can create a random narrowband signal as was done in the OpAmp
> resonator paper: http://www.dsprelated.com/showarticle/54.php
> modulate it with a carrier and pass it through a dipole system, and finally
> extract the modulation, and compare it to a light propagated signal. If
> this is done you get exactly the same answer as I showed in my simulation.
> But if this technique is used than I can not use time averagiing to improve
> SNR which is need for detection of the modulation in real experimental
> signals. I have perfomed this random modulation simulation using Agilent
> Vee Pro software which is not possible to show here in text format. But I
> can try to describe it. I took a 100V random generator and sent the signal
> through a 50 MHz cutoff (fc), 6th order LPF with the following transfer
> function [1/(j(f/fc)+1)^6]. Then I multiplied it with a 500MHz carrier and
> sent it though a light speed propagating transfer function [e^(ikr)] and
> though the magnetic component of a electric dipole transfer function
> [e^(ikr)*(-kr-i)]. Finally I extracted the modulation envelopes of the
> tranmitted signal, light speed signal, and the dipole signal. To extract
> the envelopes I used squared the signal and then passed it through a 300MHz
> cutoff (fc), 12th order LPF with the following transfer function
> [1/(j(f/fc)+1)^12].

Again, be careful even when there is a random component, as the narrow 
band predictability of the signal can easily appear to be accelerated 
propagation, as Andor demonstrated.   He hit it spot-on, IMHO, by 
showing a pulse appear to arrive before the stimulus, but then 
demonstrated that interrupting the source proved that the signal was, in 
fact, causal after all.  A train of such pulses can be modulated with a 
random component, but if one isn't extremely careful I'd think it'd be 
pretty easy to make an incorrect conclusion about what was propagation 
and what was just typical band-limited predictability.

This is why I suggested interrupting your transmit signal at some point, 
perhaps even at a zero crossing, because it may help to see what's 
really going on.

Your burden of proof is large, and it appears to me that you're not at 
all very far down the road of sufficiency if you're not addressing these 
issues head on.  Your continued use of a completely deterministic signal 
for propagation measurements suggests to me that you've not been 
measuring what you think you have been.

I think you want a signal with enough entropy to justify your claims. 
The signals you're using are nearly entropy-free.  I suspect there's a 
relationship between signal entropy and the sort of resolution or 
confidence you can have in a propagation measurement, but I don't know 
what it might be off the top of my head.   If you had such a 
demonstrated relationship you may then be able to show whether or not 
you were really measuring propagation rather than prediction. 
Otherwise folks like me (and I'm guessing some of the others here who've 
spoken up and plenty of others like them) are going to continue to point 
to the known prediction mechanisms as the far more likely explanation of 
your results rather than grandiose claims of exceeding c.






> William
>
>
>> On 3/24/2010 4:56 PM, WWalker wrote:
>>> Eric,
>>>
>>> The dicontinuity of a pulse from a dipole source propagates at light
> speed,
>>> but the pulse distorts in the nearfield because it is wideband and the
>>> dispersion is not linear over the bandwidth of the signal. In the
> farfield
>>> the pulse realigns and propagates with out distortion at the speed of
>>> light. Group speed only has meaning if the signal does not distort as
> it
>>> propagates. So in the nearfield one can not say anything about the
>>> propagation speed of a pulse, but in the farfield the pulse clearly
>>> propagates undistorted at the speed of light.
>>
>> In previous posts you seemed to be claiming that the signal was
>> propagating faster than c in the near field.   Now you are saying "in
>> the nearfield one can not say anything about the propagation speed of a
>> pulse".  Can you clear up my confusion?   Are you claiming that there is
>> a region over which the signal propagates at a speed faster than c?
>>
>>> Only a narrowband signal propagates without distortion in both the
>>> nearfield and farfield from a dipole source. This is because the
> dispersion
>>> is not very nonlinear and can approximately linear over the bandwidth of
> a
>>> narrow band signal. Since the signal does not distort as it propagates
> then
>>> the group speed can be clearly observed.
>>
>>> The dipole system is not a filter. Wave propagation from a dipole
> source
>>> occurs in free space. There is not a medium which can filter out or
> change
>>> frequency components in a signal. The transfer functions of a dipole
> source
>>> simply decribes how the field components propagate.
>>
>> Dipoles are actually bandpass filters with a center frequency determined
>> by the length of the dipole as related to the wavelength of the carrier.
>>    Efficiency drops off significantly as the wavelength changes
>> substantially from the resonant length of the dipole.
>>
>>> Clearly simple narrowband AM radio transmission contains information.
> Just
>>> turn on an AM radio and listen. The information is known to be the
>>> modulation envelope of the AM signal. My simmulation simply shows that
> in
>>> the nearfield, the modulation envelope arrives earlier in time (dt) than
> a
>>> light speed propagated modulation (dt=0.08/fc), where fc is the carrier
>>> frequency.
>>
>> You seem to be unclear on the definition of "information" in this
>> context, and I think it's a big part of what's tripping you up.  The AM
>> radio broadcast signals you like to cite contain "information" because
>> they're modulated with a significant degree of random components.   As
>> has been pointed out previously, you may not have an adequate grasp on
>> what "random" means in this context, either.   So not getting
>> "information" and "random" right in this context may be the root of
>> what's led you astray.
>>
>> I shall point out again, as have others, that if you introduce some
>> genuine randomness (i.e., information) into your test signals you will
>> be able to demonstrate whether your claims of propagation faster than c
>> are true (if you are, in fact, still claiming that) or not.  Until then
>> I will again point out that your current test signals are NOT adequate
>> for that purpose.   Jerry pointed out long ago that your signals are
>> completely deterministic, and, therefore, not random.   Anybody with the
>> most basic knowledge of trigonometry can predict the exact value of the
>> signal at ANY point in the future given the initial parameters.  In
>> fact, your simulation can do that, too!  And it is!  That proves
>> absolutely nothing and does not support the claims that you have been
>> making of propagation faster than the speed of light.
>>
>> The same can not be said of a typical AM radio broadcast signal because
>> those do, in fact, have random components due to the changing nature of
>> the modulating signals.   The parameters of your modulating signals, the
>> amplitudes and relative phases of the initial input sinusoids, do not
>> change and therefore carry no information beyond those initial
>> parameters.  This means that a short window of observation is all that
>> is needed to extract what little information there is in the signal,
>> because there isn't any additional information added beyond that.
>> After that, no information is carried in the signal other than "no
>> change", and there certainly aren't any random components by which to
>> measure information propagation.
>>
>> A static '1' has minimal information, and observing it's state past
>> reliable detection of the initial transition into that state will reveal
>> no additional information by which propagation speed can be measured.
>> This is the case with your test signals as well.  The relative phases of
>> the signals are NOT indicative of propagation velocity.  You need to add
>> a perturbation of some sort, i.e., new modulating information, and
>> detect the propagation velocity of that new modulated information.
>> Until you do that it appears to me that you have no basis on which to
>> make claims of any unexpected phenomena.
>>
>>
>>
>>>
>>> William
>>>
>>>
>>>> On 3/24/2010 8:04 AM, WWalker wrote:
>>>>> Eric,
>>>>>
>>>>> There is fundamental difference between a phase shift caused by a
>>> filter
>>>>> and a time delay caused by wave propagation across a region of space.
>>> The
>>>>> Op Amp filter circuit is simply phase shifting the harmonic
> components
>>> of
>>>>> the signal such that the overall signal appears like it has arrived
>>> before
>>>>> it was transmitted. The circuit is not really predicting the signal
> it
>>> is
>>>>> only phase shifting it.
>>>>
>>>> Yes, this is fundamental.  Still, of note, is that the way to
>>>> distinguish between such a phase shift and an increase in propagation
>>>> velocity is to introduce a perturbation, as Andor did, so that it can
> be
>>>> seen whether the prediction is due to negative group delay or
>>>> accelerated propagation.   Andor's experiment is revealing in that it
>>>> offers a method to demonstrate that what appears to be accelerated
>>>> propagation is really narrow-band prediction.   As far as I can tell
> you
>>>> have not yet done the same, and are instead claiming the rather
>>>> grandiose explanation of virtual photons (which cannot be used in the
>>>> context of information transfer) and propagation faster than the speed
>>>> of light.
>>>>
>>>> It could be cleared up pretty easily by demonstrating actual
> information
>>>> transmission, but it seems to me that you resort to hand waving
> instead.
>>>>
>>>>> In my system, the time delay of the signal is completely due to wave
>>>>> propagation across space. It is not a filter.
>>>>
>>>> You have not yet demonstrated that.
>>>>
>>>>> The simulation I presented simply shows the time delay of the
> modulation
>>> of
>>>>> an AM signal transmission between two nearfield dipole antennas. If
> you
>>>>> zoom in one can see that the modulations arrive earlier than a light
>>>>> propagated signal.
>>>>
>>>> Except that with the signals you're using the propagation cannot be
>>>> distinguished from a phase shift.   Again, the point of Andor's paper
> is
>>>> that there's a simple way to distinguish the difference.   Until you
> do
>>>> so you should not expect much respect of your grandiose claims when
>>>> there's a much simpler explanation.
>>>>
>>>>> This is not phase velocity, this is group velocity i.e. time delay of
>>> the
>>>>> envelope.
>>>>>
>>>>> William
>>>>
>>>> It doesn't matter which it is or whether the conditions are linear so
>>>> that they're the same, you haven't demonstrated that the propagation
> has
>>>> accelerated.   Either demonstrate some actual information transmission
>>>> or expect people to keep pushing back on you.  You have a high burden
> of
>>>> proof to make the claims that you're making, but you don't seem to
> want
>>>> to offer anything substantial.
>>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>>>>> Eric,
>>>>>>>
>>>>>>> Interesting article, but I don't see how it applies to my system.
> The
>>>>>>> system described in the paper is a bandpass filter in a feedback
>>> loop,
>>>>>>> where the bandpass filter phase function is altered by the
> feedback.
>>>>> The
>>>>>>> feedback forces the endpoints of the phase to zero, creating
> regions
>>> of
>>>>>>> possitive slope, which yield negative group delays for narrow band
>>>>> signals.
>>>>>>> This causes narrow band signals at the output of the circuit appear
>>> to
>>>>>>> arrive earlier than signals at the input of the circuit. Because
> the
>>>>>>> information in the signals is slightly redundant, the circuit is
> able
>>>>> to
>>>>>>> reconstruct future parts of the signal from the present part of the
>>>>>>> signal.
>>>>>>
>>>>>> Snipped context to allow bottom-posting.
>>>>>>
>>>>>> Feedback is not necessary to produce negative group delay.   Here's
>>>>>> another example with a passive notch filter that exhibits negative
>>> group
>>>>>> delay.
>>>>>>
>>>>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>>>>
>>>>>> It doesn't matter what's inside a black box if it has a negative
> group
>>>>>> delay characteristic if the transfer function is LTI.   Whether
>>> there's
>>>>>> feedback or not in the implementation is inconsequential.   Consider
>>>>>> that the passive notch filter could also be implemented as an active
>>>>>> circuit with feedback, and if the transfer functions are equivalent
>>> they
>>>>>> are functionally equivalent.   This is fundamental.  I don't think
> the
>>>>>> feedback has anything to do with it.
>>>>>>
>>>>>> You're argument on the redundancy, though, is spot-on.   Note that,
> as
>>>>>> others have already pointed out multiple times, the signals you're
>>> using
>>>>>> in your experiment are HIGHLY redundant, so much so that they carry
>>>>>> almost no information.   These signals are therefore not suitable
> for
>>>>>> proving anything about information propagation.
>>>>>>
>>>>>>
>>>>>>> First of all, this is a circuit which alters the phase function
> with
>>>>>>> respect to time and not space, as it is in my system. The phase
>>> function
>>>>> in
>>>>>>> the circuit is not due to wave propagaton, where mine is.
>>>>>>
>>>>>> As far as I've been able to tell, your evidence is based on a
>>>>>> simulation, in which case dimensionalities are abstractions.   You
> are
>>>>>> not performing anything in either time or space, you're performing a
>>>>>> numerical simulation.  Space-time transforms are not at all unusual
>>> and
>>>>>> it is likely that a substitution is easily performed.  Nothing has
>>>>>> propagated in your simulation in either time or space.
>>>>>>
>>>>>>> Secondly,unlike the circuit, my system is causal. The recieved
> signal
>>> in
>>>>> my
>>>>>>> system arrives after the signal is transmitted. It just travels
>>> faster
>>>>> than
>>>>>>> light.
>>>>>>
>>>>>> Uh, the circuit is causal.  That was the point.
>>>>>>
>>>>>> You have not demonstrated that your system is causal or not causal.
>>>>>> That cannot be concluded using the waveforms you show in your paper
>>> due
>>>>>> to the high determinism and narrow band characteristics.
>>>>>>
>>>>>>> Thirdly, the negative group delay in the circuit was accomplished
> by
>>>>> using
>>>>>>> feedback which does not exist in my system.
>>>>>>
>>>>>> As I stated above, this is inconsequential.
>>>>>>
>>>>>>
>>>>>>> Information (modulations) are clearly transmitted using narrowband
> AM
>>>>> radio
>>>>>>> communication, just listen to an AM radio. The simulation I
> presented
>>>>>>> simply shows that random AM modulations arrive undistorted across
>>> space,
>>>>> in
>>>>>>> the nearfield, earlier than a light speed propagated signal.
>>>>>>
>>>>>> Your simulation does not demonstrate that.  Turn the signal off,
> even
>>> at
>>>>>> a zero crossing if you want to minimize perturbations, and see what
>>>>> happens.
>>>>>>
>>>>>>> Signal purturbations can not be used to measure the signal
>>> propagation
>>>>> in
>>>>>>> the nearfield because they distort in the nearfield, and group
> speed
>>> has
>>>>> no
>>>>>>> meaning if the signal distorts as it propagates.
>>>>>>>
>>>>>>> William
>>>>>>
>>>>>> If you cannot use a perturbation (i.e., information transmission) to
>>>>>> measure signal propagation then you cannot demonstrate the speed of
>>>>>> information propagation.   Until you can actually demonstrate
>>> something
>>>>>> other than phase velocity (which is NOT information transmission and
>>>>>> many here have acknowledged can be faster than c, as do I), then you
>>>>>> cannot make the conclusions that you are claiming.
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Eric Jacobsen
>>>>>> Minister of Algorithms
>>>>>> Abineau Communications
>>>>>> http://www.abineau.com
>>>>>>
>>>>
>>>>
>>>> --
>>>> Eric Jacobsen
>>>> Minister of Algorithms
>>>> Abineau Communications
>>>> http://www.abineau.com
>>>>
>>
>>
>> --
>> Eric Jacobsen
>> Minister of Algorithms
>> Abineau Communications
>> http://www.abineau.com
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Jerry Avins wrote:
> WWalker wrote:
>> Jerry,
>>
>> I have tested real dipole antennas using a RF Network analyser and after
>> compensating for the electrical filter characteristics of the antenna, I
>> get the nonlinear dispersion curves shown in my paper. The nonlinear
>> dispersion is a real observable and measureable phenomina. 
> 
> I believe that. I'm not sure what you mean by nonlinear dispersion, but 
> I can guess. Dispersion is the dependence of velocity on frequency. A 
> assume that with nonlinear dispersion, the dependence relationship 
> departs markedly from a straight line. All the cases I know of apparent 
> superluminal energy velocities arise from instances of anomalous 
> dispersion. Upon analysis, all turn out to be apparent only.
> 
>> Here is another paper that presents an NEC RF numerical analysis on a
>> dipole and shows the nonlinear nearfield dispersion is real and
>> observable:
>> http://ceta.mit.edu/pier/pier.php?paper=0505121
> 
> Thank you. Tha abstract is interesting. I will read the gull paper when 
> there is more time. The title of reference 2 is noteworthy. it is "Wave 
> propagation faster than light," not "Information propagation faster than 
> light." There's a big difference.

An interesting passage near the beginning of that paper:

     "Of course there is no mystery involved here. The pitfall, if not
     embarrassing at least instructive, is that ordinary plane-wave
     thinking is applied to a mixture of traveling and reactive fields.
     In this article we seek to demonstrate, by means of an elementary
     theoretical exercise, [68 Sten and Hujanen] that the phase velocity
     near sinusoidally oscillating point dipoles does indeed exceed the
     speed of light, without endangering the law of causality. The effect
     is merely a result of the transition from the quasistatic
     near-field, where the fields are 'in phase' with the source, to the
     far-field, where the field phases depart from kr by a phase angle of
     π/2. In the time-domain the phenomenon manifests itself as a gradual
     deformation, or a step by step differentiation, of the signal
     waveform."

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi

On 3/25/2010 9:01 AM, WWalker wrote:
> Jerry,
>
> I have tested real dipole antennas using a RF Network analyser and after
> compensating for the electrical filter characteristics of the antenna, I
> get the nonlinear dispersion curves shown in my paper. The nonlinear
> dispersion is a real observable and measureable phenomina.
>
> Here is another paper that presents an NEC RF numerical analysis on a
> dipole and shows the nonlinear nearfield dispersion is real and
> observable:
> http://ceta.mit.edu/pier/pier.php?paper=0505121
>
> William

FWIW, a quick read of that paper seems to support exactly what Jerry and 
I and others have been saying.  The phase response of the near-field 
makes it behave similarly to a filter with negative group delay.  The 
author even points this out about Fig. 2b, where the pulse appears to 
accelerate.

It is not at all hard to believe that dispersion that leads to apparent 
non-causal behavior in passive or active filters could also seem to 
appear as signal propagation faster than c.


>> Eric Jacobsen wrote:
>>
>>    ...
>>
>>> Dipoles are actually bandpass filters with a center frequency determined
>
>>> by the length of the dipole as related to the wavelength of the carrier.
>
>>>    Efficiency drops off significantly as the wavelength changes
>>> substantially from the resonant length of the dipole.
>>
>> Herein lies the fallacy that is at the heart of what I see as self
>> deception. Eric describes a real dipole, while Walter's simulation is
>> constructed around an ideal one. An ideal dipole is a limit as the
>> length of a real dipole goes to zero while the power it radiates remains
>> constant. (Compare to an impulse: a pulse whose width goes to zero while
>> its area remains constant.) Such abstractions are useful for brushing
>> aside irrelevant details while retaining relevant relationships. They
>> remain useful only so long as the ignored details remain irrelevant. For
>> example, it is inappropriate to inquire about the voltage gradient along
>> an ideal diode.
>>
>> An example might clarify the limit of an abstraction's utility. Consider
>> a ball bouncing on a flat surface, such that every bounce's duration is
>> 90% of that of the previous bounce. The ball is initially dropped from
>> such a height that the first bounce lasts exactly one second. It is not
>> difficult to show that the ball will come to rest after ten seconds. In
>> that interval, how many times will the ball bounce?
>>
>> In dipoles, the extents of the near field are related to the dimensions
>> of the dipole. We can expect an ideal dipole, having zero length, to
>> have a very peculiar calculated near field.
>>
>>    ...
>>
>> Jerry
>> --
>> Discovery consists of seeing what everybody has seen, and thinking what
>> nobody has thought.    .. Albert Szent-Gyorgi
>> �����������������������������������������������������������������������
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric Jacobsen <eric.jacobsen@ieee.org> wrote:
> On 3/24/2010 8:04 AM, WWalker wrote:

>> There is fundamental difference between a phase shift caused by a filter
>> and a time delay caused by wave propagation across a region of space. The
>> Op Amp filter circuit is simply phase shifting the harmonic components of
>> the signal such that the overall signal appears like it has arrived before
>> it was transmitted. The circuit is not really predicting the signal it is
>> only phase shifting it.
 
> Yes, this is fundamental.  Still, of note, is that the way to 
> distinguish between such a phase shift and an increase in propagation 
> velocity is to introduce a perturbation, as Andor did, so that it can be 
> seen whether the prediction is due to negative group delay or 
> accelerated propagation.   

Well, for a narrow-band signal you are somewhat limited on the
kind of perturbations you can make and still be narrow band.
Getting to most signal inside a given band, though, is the reason
why we have so many complicated modulation methods.  

> Andor's experiment is revealing in that it 
> offers a method to demonstrate that what appears to be accelerated 
> propagation is really narrow-band prediction.   As far as I can tell you 
> have not yet done the same, and are instead claiming the rather 
> grandiose explanation of virtual photons (which cannot be used in the 
> context of information transfer) and propagation faster than the speed 
> of light.

I believe that this has actually been done as an optics problem.
There are materials that, for an appropriate input signal, can
appear to generate the output faster than it should be able to
get there.  It is, as you say, related to the predictability
of the signal.  
 
> It could be cleared up pretty easily by demonstrating actual information 
> transmission, but it seems to me that you resort to hand waving instead.

Well, it is more complicated in the near field case.
For one, it is harder to know what distance to use.  The size
of the antenna is very important.  But also near field isn't
very useful for sending signals long distances.  If you increase
the wavelength (to increase the range of near-field) then you
necessarily go to lower carrier and lower modulation frequencies.

-- glen

Jerry Avins <jya@ieee.org> wrote:
> Eric Jacobsen wrote:
 
>> Dipoles are actually bandpass filters with a center frequency determined 
>> by the length of the dipole as related to the wavelength of the carrier. 
>>   Efficiency drops off significantly as the wavelength changes 
>> substantially from the resonant length of the dipole.
 
> Herein lies the fallacy that is at the heart of what I see as self 
> deception. Eric describes a real dipole, while Walter's simulation is 
> constructed around an ideal one. An ideal dipole is a limit as the 
> length of a real dipole goes to zero while the power it radiates remains 
> constant. (Compare to an impulse: a pulse whose width goes to zero while 
> its area remains constant.) Such abstractions are useful for brushing 
> aside irrelevant details while retaining relevant relationships. They 
> remain useful only so long as the ignored details remain irrelevant. For 
> example, it is inappropriate to inquire about the voltage gradient along 
> an ideal diode.

In addition, real dipoles have width and/or depth.  (Usually rods
of some radius and length.)  The radius affects the resonance.
When measuring the distance from a real dipole, with length, width,
and depth, and in near field, what points do you measure between?
 
> In dipoles, the extents of the near field are related to the dimensions 
> of the dipole. We can expect an ideal dipole, having zero length, to 
> have a very peculiar calculated near field.

-- glen

Eric,

I am not sure adding two signals is deterministic independant of the time
span it is viewed. The signal only repeats after the modulation time
2/(f2-f1). One needs to sample the signal over this entire time period to
be sure what the equation the signal corresponds to enabling one to say it
is deterministic. If one only views the signal over a portion of the
modulation peroid, one cannot be sure whether it is predictable because it
could easily change from predictability when viewed over a larger time
period. This is what the autocorrolation experiment of the this signal
shows. Only after a modulation period does one see significant sidelobes in
the triangular autocorrolation signal.   

I think an important question to resolve is if the dipole system is a
filter or not. Filters can only phase shift signals, whereas a dipole
generates a true time delay due to wave propagation. It is clear that this
is true in the farfield. Why should it be different in the nearfield? 

With my last simulation I obtained the same superluminal results using a
filtered an extremly nondeterministic random signal. If the dipole system
is not a filter, how could the modulation envelope arrive sooner than a
light propagated signal? 

Your last comment regarding the effects of noise are very impotant. As I
mentioned at the very start of this discussion (thread), in order to prove
information propagates faster than light in the nearfield of a dipole, one
has to measure the time delay of the modulation (tp) and also show that it
is possible to extract the information in a fraction of a carrier cycle
(td). This is because the superluminal phenomina only occurs over a
fraction of a carrier period and v=d/(tp+td. I am very certain that in a
nearfield dipole system, the modulations of narrow band AM signals can be
observed to arrive earlier in time than a light speed propagated signal.
What I am not sure is wheather the modulations can be extracted in a
fraction of a carrier cycle with real AM signals which noise. This is why I
have contacted this group. From my investigations, the usual signal
processing techniques do not work. Simple diode/mixer low pass filtering
cannot be used because the filter requires more than a fraction of a
carrier cycle to extract the modulation. FFT has the same problem. 

William


>On 3/25/2010 8:45 AM, WWalker wrote:
>> Eric,
>>
>> A narrow band AM signal propagates undistorted and faster than light in
the
>> nearfield and reduces to the speed of light as it goes into the
farfield. A
>> pulse distorts in the nearfield and and realigns as it goes into the
>> farfield. When the pulse is distorted, one cannot say anything about
the
>> speed of the pulse. To transmit information faster than light one must
use
>> narrowband signals like AM and transmitt and receive them in the
nearfield
>> of the carrier.
>>
>> It is true that a real dipole anntena has filter characteristics. The
>> simulation I presented is an idealized dipole like an oscillating
electron
>> which does not have filter characteristics. In an experiment with real
>> antennas one would have to subtract out the phase shifts due to the
>> antennas filter characteristics so that one only sees the time delay
>> behavior of the propagating fields.
>>
>> The signals I used in my simulation are a changing modulation over the
time
>> window of analysis. The changing modulation does not repeat over this
>> window. It is true that they are created from deterministic signals.
>> Bassically I generated a beat frequency modulation which has a carrier
and
>> a modulation frequency. Provided the window of analysis is smaller than
a
>> modulation time period, the modulation pattern does not repeat. After a
>> modulation period the patern repeats again. I chose this type of signal
>> because it is a changing pattern which eventually repeats, enabling me
to
>> trigger it in a real experient and also enabling me to do time
averaging
>> which will help a lot with improving the SNR if a experimental signal.
>
>The period of the signal isn't necessarily consequential, the fact that 
>it is not random is.  The point being that the signal you are using is 
>not suitable for measuring propagation at the resolution you're 
>interested in because it is a deterministic signal.   Even when there's 
>a component that is randomly changing with time it is easy to get fooled 
>by the nature of narrowband signals, and that was pretty much a big 
>point of Andor's paper.  I'm beginning to see why he chose the title 
>that he did.
>
>> When perform an autocorrelation of the modulation I used in my
simulation,
>> I see a triangular signal with a peak at the time of the analysis time
>> window, indicating that the signal has no obserable repetition pattern
of
>> the this time. Only after I increase the analysis time window greater
than
>> the modulation period do I get significant sidelobes in the
autocorrelation
>> signal, indicating that the pattern repeats after each multiple of a
>> modulation cycle.
>
>Again, how many periods you observe isn't what matters when the signal 
>is completely deterministic.  You're just observing the same, 
>informationally-static signal over different periods of time.  That 
>tells you little to nothing about the propagation of information.
>
>
>> Of course I can create a random narrowband signal as was done in the
OpAmp
>> resonator paper: http://www.dsprelated.com/showarticle/54.php
>> modulate it with a carrier and pass it through a dipole system, and
finally
>> extract the modulation, and compare it to a light propagated signal. If
>> this is done you get exactly the same answer as I showed in my
simulation.
>> But if this technique is used than I can not use time averagiing to
improve
>> SNR which is need for detection of the modulation in real experimental
>> signals. I have perfomed this random modulation simulation using
Agilent
>> Vee Pro software which is not possible to show here in text format. But
I
>> can try to describe it. I took a 100V random generator and sent the
signal
>> through a 50 MHz cutoff (fc), 6th order LPF with the following transfer
>> function [1/(j(f/fc)+1)^6]. Then I multiplied it with a 500MHz carrier
and
>> sent it though a light speed propagating transfer function [e^(ikr)]
and
>> though the magnetic component of a electric dipole transfer function
>> [e^(ikr)*(-kr-i)]. Finally I extracted the modulation envelopes of the
>> tranmitted signal, light speed signal, and the dipole signal. To
extract
>> the envelopes I used squared the signal and then passed it through a
300MHz
>> cutoff (fc), 12th order LPF with the following transfer function
>> [1/(j(f/fc)+1)^12].
>
>Again, be careful even when there is a random component, as the narrow 
>band predictability of the signal can easily appear to be accelerated 
>propagation, as Andor demonstrated.   He hit it spot-on, IMHO, by 
>showing a pulse appear to arrive before the stimulus, but then 
>demonstrated that interrupting the source proved that the signal was, in 
>fact, causal after all.  A train of such pulses can be modulated with a 
>random component, but if one isn't extremely careful I'd think it'd be 
>pretty easy to make an incorrect conclusion about what was propagation 
>and what was just typical band-limited predictability.
>
>This is why I suggested interrupting your transmit signal at some point, 
>perhaps even at a zero crossing, because it may help to see what's 
>really going on.
>
>Your burden of proof is large, and it appears to me that you're not at 
>all very far down the road of sufficiency if you're not addressing these 
>issues head on.  Your continued use of a completely deterministic signal 
>for propagation measurements suggests to me that you've not been 
>measuring what you think you have been.
>
>I think you want a signal with enough entropy to justify your claims. 
>The signals you're using are nearly entropy-free.  I suspect there's a 
>relationship between signal entropy and the sort of resolution or 
>confidence you can have in a propagation measurement, but I don't know 
>what it might be off the top of my head.   If you had such a 
>demonstrated relationship you may then be able to show whether or not 
>you were really measuring propagation rather than prediction. 
>Otherwise folks like me (and I'm guessing some of the others here who've 
>spoken up and plenty of others like them) are going to continue to point 
>to the known prediction mechanisms as the far more likely explanation of 
>your results rather than grandiose claims of exceeding c.
>
>
>
>
>
>
>> William
>>
>>
>>> On 3/24/2010 4:56 PM, WWalker wrote:
>>>> Eric,
>>>>
>>>> The dicontinuity of a pulse from a dipole source propagates at light
>> speed,
>>>> but the pulse distorts in the nearfield because it is wideband and
the
>>>> dispersion is not linear over the bandwidth of the signal. In the
>> farfield
>>>> the pulse realigns and propagates with out distortion at the speed of
>>>> light. Group speed only has meaning if the signal does not distort as
>> it
>>>> propagates. So in the nearfield one can not say anything about the
>>>> propagation speed of a pulse, but in the farfield the pulse clearly
>>>> propagates undistorted at the speed of light.
>>>
>>> In previous posts you seemed to be claiming that the signal was
>>> propagating faster than c in the near field.   Now you are saying "in
>>> the nearfield one can not say anything about the propagation speed of
a
>>> pulse".  Can you clear up my confusion?   Are you claiming that there
is
>>> a region over which the signal propagates at a speed faster than c?
>>>
>>>> Only a narrowband signal propagates without distortion in both the
>>>> nearfield and farfield from a dipole source. This is because the
>> dispersion
>>>> is not very nonlinear and can approximately linear over the bandwidth
of
>> a
>>>> narrow band signal. Since the signal does not distort as it
propagates
>> then
>>>> the group speed can be clearly observed.
>>>
>>>> The dipole system is not a filter. Wave propagation from a dipole
>> source
>>>> occurs in free space. There is not a medium which can filter out or
>> change
>>>> frequency components in a signal. The transfer functions of a dipole
>> source
>>>> simply decribes how the field components propagate.
>>>
>>> Dipoles are actually bandpass filters with a center frequency
determined
>>> by the length of the dipole as related to the wavelength of the
carrier.
>>>    Efficiency drops off significantly as the wavelength changes
>>> substantially from the resonant length of the dipole.
>>>
>>>> Clearly simple narrowband AM radio transmission contains information.
>> Just
>>>> turn on an AM radio and listen. The information is known to be the
>>>> modulation envelope of the AM signal. My simmulation simply shows
that
>> in
>>>> the nearfield, the modulation envelope arrives earlier in time (dt)
than
>> a
>>>> light speed propagated modulation (dt=0.08/fc), where fc is the
carrier
>>>> frequency.
>>>
>>> You seem to be unclear on the definition of "information" in this
>>> context, and I think it's a big part of what's tripping you up.  The
AM
>>> radio broadcast signals you like to cite contain "information" because
>>> they're modulated with a significant degree of random components.   As
>>> has been pointed out previously, you may not have an adequate grasp on
>>> what "random" means in this context, either.   So not getting
>>> "information" and "random" right in this context may be the root of
>>> what's led you astray.
>>>
>>> I shall point out again, as have others, that if you introduce some
>>> genuine randomness (i.e., information) into your test signals you will
>>> be able to demonstrate whether your claims of propagation faster than
c
>>> are true (if you are, in fact, still claiming that) or not.  Until
then
>>> I will again point out that your current test signals are NOT adequate
>>> for that purpose.   Jerry pointed out long ago that your signals are
>>> completely deterministic, and, therefore, not random.   Anybody with
the
>>> most basic knowledge of trigonometry can predict the exact value of
the
>>> signal at ANY point in the future given the initial parameters.  In
>>> fact, your simulation can do that, too!  And it is!  That proves
>>> absolutely nothing and does not support the claims that you have been
>>> making of propagation faster than the speed of light.
>>>
>>> The same can not be said of a typical AM radio broadcast signal
because
>>> those do, in fact, have random components due to the changing nature
of
>>> the modulating signals.   The parameters of your modulating signals,
the
>>> amplitudes and relative phases of the initial input sinusoids, do not
>>> change and therefore carry no information beyond those initial
>>> parameters.  This means that a short window of observation is all that
>>> is needed to extract what little information there is in the signal,
>>> because there isn't any additional information added beyond that.
>>> After that, no information is carried in the signal other than "no
>>> change", and there certainly aren't any random components by which to
>>> measure information propagation.
>>>
>>> A static '1' has minimal information, and observing it's state past
>>> reliable detection of the initial transition into that state will
reveal
>>> no additional information by which propagation speed can be measured.
>>> This is the case with your test signals as well.  The relative phases
of
>>> the signals are NOT indicative of propagation velocity.  You need to
add
>>> a perturbation of some sort, i.e., new modulating information, and
>>> detect the propagation velocity of that new modulated information.
>>> Until you do that it appears to me that you have no basis on which to
>>> make claims of any unexpected phenomena.
>>>
>>>
>>>
>>>>
>>>> William
>>>>
>>>>
>>>>> On 3/24/2010 8:04 AM, WWalker wrote:
>>>>>> Eric,
>>>>>>
>>>>>> There is fundamental difference between a phase shift caused by a
>>>> filter
>>>>>> and a time delay caused by wave propagation across a region of
space.
>>>> The
>>>>>> Op Amp filter circuit is simply phase shifting the harmonic
>> components
>>>> of
>>>>>> the signal such that the overall signal appears like it has arrived
>>>> before
>>>>>> it was transmitted. The circuit is not really predicting the signal
>> it
>>>> is
>>>>>> only phase shifting it.
>>>>>
>>>>> Yes, this is fundamental.  Still, of note, is that the way to
>>>>> distinguish between such a phase shift and an increase in
propagation
>>>>> velocity is to introduce a perturbation, as Andor did, so that it
can
>> be
>>>>> seen whether the prediction is due to negative group delay or
>>>>> accelerated propagation.   Andor's experiment is revealing in that
it
>>>>> offers a method to demonstrate that what appears to be accelerated
>>>>> propagation is really narrow-band prediction.   As far as I can tell
>> you
>>>>> have not yet done the same, and are instead claiming the rather
>>>>> grandiose explanation of virtual photons (which cannot be used in
the
>>>>> context of information transfer) and propagation faster than the
speed
>>>>> of light.
>>>>>
>>>>> It could be cleared up pretty easily by demonstrating actual
>> information
>>>>> transmission, but it seems to me that you resort to hand waving
>> instead.
>>>>>
>>>>>> In my system, the time delay of the signal is completely due to
wave
>>>>>> propagation across space. It is not a filter.
>>>>>
>>>>> You have not yet demonstrated that.
>>>>>
>>>>>> The simulation I presented simply shows the time delay of the
>> modulation
>>>> of
>>>>>> an AM signal transmission between two nearfield dipole antennas. If
>> you
>>>>>> zoom in one can see that the modulations arrive earlier than a
light
>>>>>> propagated signal.
>>>>>
>>>>> Except that with the signals you're using the propagation cannot be
>>>>> distinguished from a phase shift.   Again, the point of Andor's
paper
>> is
>>>>> that there's a simple way to distinguish the difference.   Until you
>> do
>>>>> so you should not expect much respect of your grandiose claims when
>>>>> there's a much simpler explanation.
>>>>>
>>>>>> This is not phase velocity, this is group velocity i.e. time delay
of
>>>> the
>>>>>> envelope.
>>>>>>
>>>>>> William
>>>>>
>>>>> It doesn't matter which it is or whether the conditions are linear
so
>>>>> that they're the same, you haven't demonstrated that the propagation
>> has
>>>>> accelerated.   Either demonstrate some actual information
transmission
>>>>> or expect people to keep pushing back on you.  You have a high
burden
>> of
>>>>> proof to make the claims that you're making, but you don't seem to
>> want
>>>>> to offer anything substantial.
>>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>>>>>> Eric,
>>>>>>>>
>>>>>>>> Interesting article, but I don't see how it applies to my system.
>> The
>>>>>>>> system described in the paper is a bandpass filter in a feedback
>>>> loop,
>>>>>>>> where the bandpass filter phase function is altered by the
>> feedback.
>>>>>> The
>>>>>>>> feedback forces the endpoints of the phase to zero, creating
>> regions
>>>> of
>>>>>>>> possitive slope, which yield negative group delays for narrow
band
>>>>>> signals.
>>>>>>>> This causes narrow band signals at the output of the circuit
appear
>>>> to
>>>>>>>> arrive earlier than signals at the input of the circuit. Because
>> the
>>>>>>>> information in the signals is slightly redundant, the circuit is
>> able
>>>>>> to
>>>>>>>> reconstruct future parts of the signal from the present part of
the
>>>>>>>> signal.
>>>>>>>
>>>>>>> Snipped context to allow bottom-posting.
>>>>>>>
>>>>>>> Feedback is not necessary to produce negative group delay.  
Here's
>>>>>>> another example with a passive notch filter that exhibits negative
>>>> group
>>>>>>> delay.
>>>>>>>
>>>>>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>>>>>
>>>>>>> It doesn't matter what's inside a black box if it has a negative
>> group
>>>>>>> delay characteristic if the transfer function is LTI.   Whether
>>>> there's
>>>>>>> feedback or not in the implementation is inconsequential.  
Consider
>>>>>>> that the passive notch filter could also be implemented as an
active
>>>>>>> circuit with feedback, and if the transfer functions are
equivalent
>>>> they
>>>>>>> are functionally equivalent.   This is fundamental.  I don't think
>> the
>>>>>>> feedback has anything to do with it.
>>>>>>>
>>>>>>> You're argument on the redundancy, though, is spot-on.   Note
that,
>> as
>>>>>>> others have already pointed out multiple times, the signals you're
>>>> using
>>>>>>> in your experiment are HIGHLY redundant, so much so that they
carry
>>>>>>> almost no information.   These signals are therefore not suitable
>> for
>>>>>>> proving anything about information propagation.
>>>>>>>
>>>>>>>
>>>>>>>> First of all, this is a circuit which alters the phase function
>> with
>>>>>>>> respect to time and not space, as it is in my system. The phase
>>>> function
>>>>>> in
>>>>>>>> the circuit is not due to wave propagaton, where mine is.
>>>>>>>
>>>>>>> As far as I've been able to tell, your evidence is based on a
>>>>>>> simulation, in which case dimensionalities are abstractions.   You
>> are
>>>>>>> not performing anything in either time or space, you're performing
a
>>>>>>> numerical simulation.  Space-time transforms are not at all
unusual
>>>> and
>>>>>>> it is likely that a substitution is easily performed.  Nothing has
>>>>>>> propagated in your simulation in either time or space.
>>>>>>>
>>>>>>>> Secondly,unlike the circuit, my system is causal. The recieved
>> signal
>>>> in
>>>>>> my
>>>>>>>> system arrives after the signal is transmitted. It just travels
>>>> faster
>>>>>> than
>>>>>>>> light.
>>>>>>>
>>>>>>> Uh, the circuit is causal.  That was the point.
>>>>>>>
>>>>>>> You have not demonstrated that your system is causal or not
causal.
>>>>>>> That cannot be concluded using the waveforms you show in your
paper
>>>> due
>>>>>>> to the high determinism and narrow band characteristics.
>>>>>>>
>>>>>>>> Thirdly, the negative group delay in the circuit was accomplished
>> by
>>>>>> using
>>>>>>>> feedback which does not exist in my system.
>>>>>>>
>>>>>>> As I stated above, this is inconsequential.
>>>>>>>
>>>>>>>
>>>>>>>> Information (modulations) are clearly transmitted using
narrowband
>> AM
>>>>>> radio
>>>>>>>> communication, just listen to an AM radio. The simulation I
>> presented
>>>>>>>> simply shows that random AM modulations arrive undistorted across
>>>> space,
>>>>>> in
>>>>>>>> the nearfield, earlier than a light speed propagated signal.
>>>>>>>
>>>>>>> Your simulation does not demonstrate that.  Turn the signal off,
>> even
>>>> at
>>>>>>> a zero crossing if you want to minimize perturbations, and see
what
>>>>>> happens.
>>>>>>>
>>>>>>>> Signal purturbations can not be used to measure the signal
>>>> propagation
>>>>>> in
>>>>>>>> the nearfield because they distort in the nearfield, and group
>> speed
>>>> has
>>>>>> no
>>>>>>>> meaning if the signal distorts as it propagates.
>>>>>>>>
>>>>>>>> William
>>>>>>>
>>>>>>> If you cannot use a perturbation (i.e., information transmission)
to
>>>>>>> measure signal propagation then you cannot demonstrate the speed
of
>>>>>>> information propagation.   Until you can actually demonstrate
>>>> something
>>>>>>> other than phase velocity (which is NOT information transmission
and
>>>>>>> many here have acknowledged can be faster than c, as do I), then
you
>>>>>>> cannot make the conclusions that you are claiming.
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Eric Jacobsen
>>>>>>> Minister of Algorithms
>>>>>>> Abineau Communications
>>>>>>> http://www.abineau.com
>>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Eric Jacobsen
>>>>> Minister of Algorithms
>>>>> Abineau Communications
>>>>> http://www.abineau.com
>>>>>
>>>
>>>
>>> --
>>> Eric Jacobsen
>>> Minister of Algorithms
>>> Abineau Communications
>>> http://www.abineau.com
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

WWalker wrote:
> Eric,
> 
> I am not sure adding two signals is deterministic independant of the time
> span it is viewed. The signal only repeats after the modulation time
> 2/(f2-f1). One needs to sample the signal over this entire time period to
> be sure what the equation the signal corresponds to enabling one to say it
> is deterministic. If one only views the signal over a portion of the
> modulation peroid, one cannot be sure whether it is predictable because it
> could easily change from predictability when viewed over a larger time
> period. This is what the autocorrolation experiment of the this signal
> shows. Only after a modulation period does one see significant sidelobes in
> the triangular autocorrolation signal.   
> 
> I think an important question to resolve is if the dipole system is a
> filter or not. Filters can only phase shift signals, whereas a dipole
> generates a true time delay due to wave propagation. It is clear that this
> is true in the farfield. Why should it be different in the nearfield? 
> 
> With my last simulation I obtained the same superluminal results using a
> filtered an extremly nondeterministic random signal. If the dipole system
> is not a filter, how could the modulation envelope arrive sooner than a
> light propagated signal? 
> 
> Your last comment regarding the effects of noise are very impotant. As I
> mentioned at the very start of this discussion (thread), in order to prove
> information propagates faster than light in the nearfield of a dipole, one
> has to measure the time delay of the modulation (tp) and also show that it
> is possible to extract the information in a fraction of a carrier cycle
> (td). This is because the superluminal phenomina only occurs over a
> fraction of a carrier period and v=d/(tp+td. I am very certain that in a
> nearfield dipole system, the modulations of narrow band AM signals can be
> observed to arrive earlier in time than a light speed propagated signal.
> What I am not sure is wheather the modulations can be extracted in a
> fraction of a carrier cycle with real AM signals which noise. This is why I
> have contacted this group. From my investigations, the usual signal
> processing techniques do not work. Simple diode/mixer low pass filtering
> cannot be used because the filter requires more than a fraction of a
> carrier cycle to extract the modulation. FFT has the same problem. 
> 
> William
> 
> 
>> On 3/25/2010 8:45 AM, WWalker wrote:
>>> Eric,
>>>
>>> A narrow band AM signal propagates undistorted and faster than light in
> the
>>> nearfield and reduces to the speed of light as it goes into the
> farfield. A
>>> pulse distorts in the nearfield and and realigns as it goes into the
>>> farfield. When the pulse is distorted, one cannot say anything about
> the
>>> speed of the pulse. To transmit information faster than light one must
> use
>>> narrowband signals like AM and transmitt and receive them in the
> nearfield
>>> of the carrier.
>>>
>>> It is true that a real dipole anntena has filter characteristics. The
>>> simulation I presented is an idealized dipole like an oscillating
> electron
>>> which does not have filter characteristics. In an experiment with real
>>> antennas one would have to subtract out the phase shifts due to the
>>> antennas filter characteristics so that one only sees the time delay
>>> behavior of the propagating fields.
>>>
>>> The signals I used in my simulation are a changing modulation over the
> time
>>> window of analysis. The changing modulation does not repeat over this
>>> window. It is true that they are created from deterministic signals.
>>> Bassically I generated a beat frequency modulation which has a carrier
> and
>>> a modulation frequency. Provided the window of analysis is smaller than
> a
>>> modulation time period, the modulation pattern does not repeat. After a
>>> modulation period the patern repeats again. I chose this type of signal
>>> because it is a changing pattern which eventually repeats, enabling me
> to
>>> trigger it in a real experient and also enabling me to do time
> averaging
>>> which will help a lot with improving the SNR if a experimental signal.
>> The period of the signal isn't necessarily consequential, the fact that 
>> it is not random is.  The point being that the signal you are using is 
>> not suitable for measuring propagation at the resolution you're 
>> interested in because it is a deterministic signal.   Even when there's 
>> a component that is randomly changing with time it is easy to get fooled 
>> by the nature of narrowband signals, and that was pretty much a big 
>> point of Andor's paper.  I'm beginning to see why he chose the title 
>> that he did.
>>
>>> When perform an autocorrelation of the modulation I used in my
> simulation,
>>> I see a triangular signal with a peak at the time of the analysis time
>>> window, indicating that the signal has no obserable repetition pattern
> of
>>> the this time. Only after I increase the analysis time window greater
> than
>>> the modulation period do I get significant sidelobes in the
> autocorrelation
>>> signal, indicating that the pattern repeats after each multiple of a
>>> modulation cycle.
>> Again, how many periods you observe isn't what matters when the signal 
>> is completely deterministic.  You're just observing the same, 
>> informationally-static signal over different periods of time.  That 
>> tells you little to nothing about the propagation of information.
>>
>>
>>> Of course I can create a random narrowband signal as was done in the
> OpAmp
>>> resonator paper: http://www.dsprelated.com/showarticle/54.php
>>> modulate it with a carrier and pass it through a dipole system, and
> finally
>>> extract the modulation, and compare it to a light propagated signal. If
>>> this is done you get exactly the same answer as I showed in my
> simulation.
>>> But if this technique is used than I can not use time averagiing to
> improve
>>> SNR which is need for detection of the modulation in real experimental
>>> signals. I have perfomed this random modulation simulation using
> Agilent
>>> Vee Pro software which is not possible to show here in text format. But
> I
>>> can try to describe it. I took a 100V random generator and sent the
> signal
>>> through a 50 MHz cutoff (fc), 6th order LPF with the following transfer
>>> function [1/(j(f/fc)+1)^6]. Then I multiplied it with a 500MHz carrier
> and
>>> sent it though a light speed propagating transfer function [e^(ikr)]
> and
>>> though the magnetic component of a electric dipole transfer function
>>> [e^(ikr)*(-kr-i)]. Finally I extracted the modulation envelopes of the
>>> tranmitted signal, light speed signal, and the dipole signal. To
> extract
>>> the envelopes I used squared the signal and then passed it through a
> 300MHz
>>> cutoff (fc), 12th order LPF with the following transfer function
>>> [1/(j(f/fc)+1)^12].
>> Again, be careful even when there is a random component, as the narrow 
>> band predictability of the signal can easily appear to be accelerated 
>> propagation, as Andor demonstrated.   He hit it spot-on, IMHO, by 
>> showing a pulse appear to arrive before the stimulus, but then 
>> demonstrated that interrupting the source proved that the signal was, in 
>> fact, causal after all.  A train of such pulses can be modulated with a 
>> random component, but if one isn't extremely careful I'd think it'd be 
>> pretty easy to make an incorrect conclusion about what was propagation 
>> and what was just typical band-limited predictability.
>>
>> This is why I suggested interrupting your transmit signal at some point, 
>> perhaps even at a zero crossing, because it may help to see what's 
>> really going on.
>>
>> Your burden of proof is large, and it appears to me that you're not at 
>> all very far down the road of sufficiency if you're not addressing these 
>> issues head on.  Your continued use of a completely deterministic signal 
>> for propagation measurements suggests to me that you've not been 
>> measuring what you think you have been.
>>
>> I think you want a signal with enough entropy to justify your claims. 
>> The signals you're using are nearly entropy-free.  I suspect there's a 
>> relationship between signal entropy and the sort of resolution or 
>> confidence you can have in a propagation measurement, but I don't know 
>> what it might be off the top of my head.   If you had such a 
>> demonstrated relationship you may then be able to show whether or not 
>> you were really measuring propagation rather than prediction. 
>> Otherwise folks like me (and I'm guessing some of the others here who've 
>> spoken up and plenty of others like them) are going to continue to point 
>> to the known prediction mechanisms as the far more likely explanation of 
>> your results rather than grandiose claims of exceeding c.
>>
>>
>>
>>
>>
>>
>>> William
>>>
>>>
>>>> On 3/24/2010 4:56 PM, WWalker wrote:
>>>>> Eric,
>>>>>
>>>>> The dicontinuity of a pulse from a dipole source propagates at light
>>> speed,
>>>>> but the pulse distorts in the nearfield because it is wideband and
> the
>>>>> dispersion is not linear over the bandwidth of the signal. In the
>>> farfield
>>>>> the pulse realigns and propagates with out distortion at the speed of
>>>>> light. Group speed only has meaning if the signal does not distort as
>>> it
>>>>> propagates. So in the nearfield one can not say anything about the
>>>>> propagation speed of a pulse, but in the farfield the pulse clearly
>>>>> propagates undistorted at the speed of light.
>>>> In previous posts you seemed to be claiming that the signal was
>>>> propagating faster than c in the near field.   Now you are saying "in
>>>> the nearfield one can not say anything about the propagation speed of
> a
>>>> pulse".  Can you clear up my confusion?   Are you claiming that there
> is
>>>> a region over which the signal propagates at a speed faster than c?
>>>>
>>>>> Only a narrowband signal propagates without distortion in both the
>>>>> nearfield and farfield from a dipole source. This is because the
>>> dispersion
>>>>> is not very nonlinear and can approximately linear over the bandwidth
> of
>>> a
>>>>> narrow band signal. Since the signal does not distort as it
> propagates
>>> then
>>>>> the group speed can be clearly observed.
>>>>> The dipole system is not a filter. Wave propagation from a dipole
>>> source
>>>>> occurs in free space. There is not a medium which can filter out or
>>> change
>>>>> frequency components in a signal. The transfer functions of a dipole
>>> source
>>>>> simply decribes how the field components propagate.
>>>> Dipoles are actually bandpass filters with a center frequency
> determined
>>>> by the length of the dipole as related to the wavelength of the
> carrier.
>>>>    Efficiency drops off significantly as the wavelength changes
>>>> substantially from the resonant length of the dipole.
>>>>
>>>>> Clearly simple narrowband AM radio transmission contains information.
>>> Just
>>>>> turn on an AM radio and listen. The information is known to be the
>>>>> modulation envelope of the AM signal. My simmulation simply shows
> that
>>> in
>>>>> the nearfield, the modulation envelope arrives earlier in time (dt)
> than
>>> a
>>>>> light speed propagated modulation (dt=0.08/fc), where fc is the
> carrier
>>>>> frequency.
>>>> You seem to be unclear on the definition of "information" in this
>>>> context, and I think it's a big part of what's tripping you up.  The
> AM
>>>> radio broadcast signals you like to cite contain "information" because
>>>> they're modulated with a significant degree of random components.   As
>>>> has been pointed out previously, you may not have an adequate grasp on
>>>> what "random" means in this context, either.   So not getting
>>>> "information" and "random" right in this context may be the root of
>>>> what's led you astray.
>>>>
>>>> I shall point out again, as have others, that if you introduce some
>>>> genuine randomness (i.e., information) into your test signals you will
>>>> be able to demonstrate whether your claims of propagation faster than
> c
>>>> are true (if you are, in fact, still claiming that) or not.  Until
> then
>>>> I will again point out that your current test signals are NOT adequate
>>>> for that purpose.   Jerry pointed out long ago that your signals are
>>>> completely deterministic, and, therefore, not random.   Anybody with
> the
>>>> most basic knowledge of trigonometry can predict the exact value of
> the
>>>> signal at ANY point in the future given the initial parameters.  In
>>>> fact, your simulation can do that, too!  And it is!  That proves
>>>> absolutely nothing and does not support the claims that you have been
>>>> making of propagation faster than the speed of light.
>>>>
>>>> The same can not be said of a typical AM radio broadcast signal
> because
>>>> those do, in fact, have random components due to the changing nature
> of
>>>> the modulating signals.   The parameters of your modulating signals,
> the
>>>> amplitudes and relative phases of the initial input sinusoids, do not
>>>> change and therefore carry no information beyond those initial
>>>> parameters.  This means that a short window of observation is all that
>>>> is needed to extract what little information there is in the signal,
>>>> because there isn't any additional information added beyond that.
>>>> After that, no information is carried in the signal other than "no
>>>> change", and there certainly aren't any random components by which to
>>>> measure information propagation.
>>>>
>>>> A static '1' has minimal information, and observing it's state past
>>>> reliable detection of the initial transition into that state will
> reveal
>>>> no additional information by which propagation speed can be measured.
>>>> This is the case with your test signals as well.  The relative phases
> of
>>>> the signals are NOT indicative of propagation velocity.  You need to
> add
>>>> a perturbation of some sort, i.e., new modulating information, and
>>>> detect the propagation velocity of that new modulated information.
>>>> Until you do that it appears to me that you have no basis on which to
>>>> make claims of any unexpected phenomena.
>>>>
>>>>
>>>>
>>>>> William
>>>>>
>>>>>
>>>>>> On 3/24/2010 8:04 AM, WWalker wrote:
>>>>>>> Eric,
>>>>>>>
>>>>>>> There is fundamental difference between a phase shift caused by a
>>>>> filter
>>>>>>> and a time delay caused by wave propagation across a region of
> space.
>>>>> The
>>>>>>> Op Amp filter circuit is simply phase shifting the harmonic
>>> components
>>>>> of
>>>>>>> the signal such that the overall signal appears like it has arrived
>>>>> before
>>>>>>> it was transmitted. The circuit is not really predicting the signal
>>> it
>>>>> is
>>>>>>> only phase shifting it.
>>>>>> Yes, this is fundamental.  Still, of note, is that the way to
>>>>>> distinguish between such a phase shift and an increase in
> propagation
>>>>>> velocity is to introduce a perturbation, as Andor did, so that it
> can
>>> be
>>>>>> seen whether the prediction is due to negative group delay or
>>>>>> accelerated propagation.   Andor's experiment is revealing in that
> it
>>>>>> offers a method to demonstrate that what appears to be accelerated
>>>>>> propagation is really narrow-band prediction.   As far as I can tell
>>> you
>>>>>> have not yet done the same, and are instead claiming the rather
>>>>>> grandiose explanation of virtual photons (which cannot be used in
> the
>>>>>> context of information transfer) and propagation faster than the
> speed
>>>>>> of light.
>>>>>>
>>>>>> It could be cleared up pretty easily by demonstrating actual
>>> information
>>>>>> transmission, but it seems to me that you resort to hand waving
>>> instead.
>>>>>>> In my system, the time delay of the signal is completely due to
> wave
>>>>>>> propagation across space. It is not a filter.
>>>>>> You have not yet demonstrated that.
>>>>>>
>>>>>>> The simulation I presented simply shows the time delay of the
>>> modulation
>>>>> of
>>>>>>> an AM signal transmission between two nearfield dipole antennas. If
>>> you
>>>>>>> zoom in one can see that the modulations arrive earlier than a
> light
>>>>>>> propagated signal.
>>>>>> Except that with the signals you're using the propagation cannot be
>>>>>> distinguished from a phase shift.   Again, the point of Andor's
> paper
>>> is
>>>>>> that there's a simple way to distinguish the difference.   Until you
>>> do
>>>>>> so you should not expect much respect of your grandiose claims when
>>>>>> there's a much simpler explanation.
>>>>>>
>>>>>>> This is not phase velocity, this is group velocity i.e. time delay
> of
>>>>> the
>>>>>>> envelope.
>>>>>>>
>>>>>>> William
>>>>>> It doesn't matter which it is or whether the conditions are linear
> so
>>>>>> that they're the same, you haven't demonstrated that the propagation
>>> has
>>>>>> accelerated.   Either demonstrate some actual information
> transmission
>>>>>> or expect people to keep pushing back on you.  You have a high
> burden
>>> of
>>>>>> proof to make the claims that you're making, but you don't seem to
>>> want
>>>>>> to offer anything substantial.
>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>>>>>>> Eric,
>>>>>>>>>
>>>>>>>>> Interesting article, but I don't see how it applies to my system.
>>> The
>>>>>>>>> system described in the paper is a bandpass filter in a feedback
>>>>> loop,
>>>>>>>>> where the bandpass filter phase function is altered by the
>>> feedback.
>>>>>>> The
>>>>>>>>> feedback forces the endpoints of the phase to zero, creating
>>> regions
>>>>> of
>>>>>>>>> possitive slope, which yield negative group delays for narrow
> band
>>>>>>> signals.
>>>>>>>>> This causes narrow band signals at the output of the circuit
> appear
>>>>> to
>>>>>>>>> arrive earlier than signals at the input of the circuit. Because
>>> the
>>>>>>>>> information in the signals is slightly redundant, the circuit is
>>> able
>>>>>>> to
>>>>>>>>> reconstruct future parts of the signal from the present part of
> the
>>>>>>>>> signal.
>>>>>>>> Snipped context to allow bottom-posting.
>>>>>>>>
>>>>>>>> Feedback is not necessary to produce negative group delay.  
> Here's
>>>>>>>> another example with a passive notch filter that exhibits negative
>>>>> group
>>>>>>>> delay.
>>>>>>>>
>>>>>>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>>>>>>
>>>>>>>> It doesn't matter what's inside a black box if it has a negative
>>> group
>>>>>>>> delay characteristic if the transfer function is LTI.   Whether
>>>>> there's
>>>>>>>> feedback or not in the implementation is inconsequential.  
> Consider
>>>>>>>> that the passive notch filter could also be implemented as an
> active
>>>>>>>> circuit with feedback, and if the transfer functions are
> equivalent
>>>>> they
>>>>>>>> are functionally equivalent.   This is fundamental.  I don't think
>>> the
>>>>>>>> feedback has anything to do with it.
>>>>>>>>
>>>>>>>> You're argument on the redundancy, though, is spot-on.   Note
> that,
>>> as
>>>>>>>> others have already pointed out multiple times, the signals you're
>>>>> using
>>>>>>>> in your experiment are HIGHLY redundant, so much so that they
> carry
>>>>>>>> almost no information.   These signals are therefore not suitable
>>> for
>>>>>>>> proving anything about information propagation.
>>>>>>>>
>>>>>>>>
>>>>>>>>> First of all, this is a circuit which alters the phase function
>>> with
>>>>>>>>> respect to time and not space, as it is in my system. The phase
>>>>> function
>>>>>>> in
>>>>>>>>> the circuit is not due to wave propagaton, where mine is.
>>>>>>>> As far as I've been able to tell, your evidence is based on a
>>>>>>>> simulation, in which case dimensionalities are abstractions.   You
>>> are
>>>>>>>> not performing anything in either time or space, you're performing
> a
>>>>>>>> numerical simulation.  Space-time transforms are not at all
> unusual
>>>>> and
>>>>>>>> it is likely that a substitution is easily performed.  Nothing has
>>>>>>>> propagated in your simulation in either time or space.
>>>>>>>>
>>>>>>>>> Secondly,unlike the circuit, my system is causal. The recieved
>>> signal
>>>>> in
>>>>>>> my
>>>>>>>>> system arrives after the signal is transmitted. It just travels
>>>>> faster
>>>>>>> than
>>>>>>>>> light.
>>>>>>>> Uh, the circuit is causal.  That was the point.
>>>>>>>>
>>>>>>>> You have not demonstrated that your system is causal or not
> causal.
>>>>>>>> That cannot be concluded using the waveforms you show in your
> paper
>>>>> due
>>>>>>>> to the high determinism and narrow band characteristics.
>>>>>>>>
>>>>>>>>> Thirdly, the negative group delay in the circuit was accomplished
>>> by
>>>>>>> using
>>>>>>>>> feedback which does not exist in my system.
>>>>>>>> As I stated above, this is inconsequential.
>>>>>>>>
>>>>>>>>
>>>>>>>>> Information (modulations) are clearly transmitted using
> narrowband
>>> AM
>>>>>>> radio
>>>>>>>>> communication, just listen to an AM radio. The simulation I
>>> presented
>>>>>>>>> simply shows that random AM modulations arrive undistorted across
>>>>> space,
>>>>>>> in
>>>>>>>>> the nearfield, earlier than a light speed propagated signal.
>>>>>>>> Your simulation does not demonstrate that.  Turn the signal off,
>>> even
>>>>> at
>>>>>>>> a zero crossing if you want to minimize perturbations, and see
> what
>>>>>>> happens.
>>>>>>>>> Signal purturbations can not be used to measure the signal
>>>>> propagation
>>>>>>> in
>>>>>>>>> the nearfield because they distort in the nearfield, and group
>>> speed
>>>>> has
>>>>>>> no
>>>>>>>>> meaning if the signal distorts as it propagates.
>>>>>>>>>
>>>>>>>>> William
>>>>>>>> If you cannot use a perturbation (i.e., information transmission)
> to
>>>>>>>> measure signal propagation then you cannot demonstrate the speed
> of
>>>>>>>> information propagation.   Until you can actually demonstrate
>>>>> something
>>>>>>>> other than phase velocity (which is NOT information transmission
> and
>>>>>>>> many here have acknowledged can be faster than c, as do I), then
> you
>>>>>>>> cannot make the conclusions that you are claiming.

William,

I think there are a few misconceptions that need to be addressed.

DETERMINISM.  Consider the series 1, 2, 1, 2, 1. It seems pretty 
straightforward, but it's necessarily. There is no way to make an 
assured prediction of the next term. We can see a pattern *so far* but 
we have no guarantee that the pattern will continue. There are circuits 
that behave well with this sequence and its "expected" sequel is 
applied, but which become erratic if the next input were to be, say. 
-20. So while the signal is not predictable, *if we treat it as if it 
were predictable,* we can get interesting effects. That is what you seem 
to be doing.

DIPOLES AND FILTERS. A physical dipole's response is a function of 
frequency.  As such, it is a filter. It is not true that a filter has no 
delay. All filters have delay. This is especially easy to see with 
digital filters because they are constructed of delay elements, but it 
is true of all filters. Analog filters have phase shift, as you 
recognize. When that phase shift is proportional to frequency, there is 
a non-dispersive delay. A properly connected collection of inductors and 
capacitors provides a very good delay. It can simulate a long 
transmission line and delay speech. It is used in oscilloscopes to delay 
the displayed signal, allowing an entire pulse to be displayed even 
though the sweep is triggered by the pulse's rise.

The phenomenon you observe is simple. The near field is in phase with 
the dipole's excitation and falls off with the cube of distance. It 
dominates near the radiator. The far field is in quadrature with the 
dipole's excitation. It exists throughout space, falling off as the 
square of distance, so eventually it dominates. The phase at any point 
is due to the sum of these components. The disparate decay rates of the 
two field components make it appear, based on phase measurements alone, 
that the wave propagates superluminally. 'Taint so.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 3/26/2010 6:46 AM, WWalker wrote:
> Eric,
>
> I am not sure adding two signals is deterministic independant of the time
> span it is viewed. The signal only repeats after the modulation time
> 2/(f2-f1). One needs to sample the signal over this entire time period to
> be sure what the equation the signal corresponds to enabling one to say it
> is deterministic. If one only views the signal over a portion of the
> modulation peroid, one cannot be sure whether it is predictable because it
> could easily change from predictability when viewed over a larger time
> period. This is what the autocorrolation experiment of the this signal
> shows. Only after a modulation period does one see significant sidelobes in
> the triangular autocorrolation signal.

Tell me if I'm wrong, but my recollection is that you're adding a few 
sine waves together for your stimulus.   All one needs to know is the 
initial parameters of amplitude and phase for each term and the signal 
is known, completely, for all future time.   This is pretty 
deterministic.  It is also why it conveys no information beyond the 
initial parameters and therefore is a poor choice for measuring 
information propagation.  The example I gave of a static binary '1' is 
the same idea;  you can't compare the transmitted and received waveform 
and learn anything about propagation time.

 From that perspective it doesn't matter at what phase or what fraction 
of composite period the signal is observed over, as that doesn't change 
the deterministic nature of the signal or the amount of information it's 
carrying.

See Jerry's response as well.

> I think an important question to resolve is if the dipole system is a
> filter or not. Filters can only phase shift signals, whereas a dipole
> generates a true time delay due to wave propagation. It is clear that this
> is true in the farfield. Why should it be different in the nearfield?

Yes, a dipole is a filter.   The paper by Sten and Hujanen that you 
cited previously seems to me to be saying and demonstrating exactly the 
relevant issue; that the phase response of the near field is dispersive 
so that superluminal propagation seems apparent, but really isn't so. 
Again, their Figure 2 shows that pretty clearly by my reading.


> With my last simulation I obtained the same superluminal results using a
> filtered an extremly nondeterministic random signal. If the dipole system
> is not a filter, how could the modulation envelope arrive sooner than a
> light propagated signal?

See, again, Andor's paper on dsprelated.  Prediction of a band-limited 
signal can appear to be time travel or superluminal or whatever you want 
to call it, but it's not.  It's just narrow-band prediction, which is 
not magic at all.

Also see, again, Fig. 2b of the Sten and Hujanen paper.  It "appears" 
that the pulse has advanced in time before the stimulus, but that's due 
only to the dispersion of the frequency content of the signal by the 
phase response of the medium.  Figures 4, 5, and 6 in Andor's blog show 
this as well, including Fig 6 which appears to have a fair amount of 
randomness. This is why it can be easily duplicated in a numerical 
simulation: it's just a mathematical effect of the non-linear phase 
response and negative group delay in the transfer function.


> Your last comment regarding the effects of noise are very impotant. As I
> mentioned at the very start of this discussion (thread), in order to prove
> information propagates faster than light in the nearfield of a dipole, one
> has to measure the time delay of the modulation (tp) and also show that it
> is possible to extract the information in a fraction of a carrier cycle
> (td). This is because the superluminal phenomina only occurs over a
> fraction of a carrier period and v=d/(tp+td. I am very certain that in a
> nearfield dipole system, the modulations of narrow band AM signals can be
> observed to arrive earlier in time than a light speed propagated signal.
> What I am not sure is wheather the modulations can be extracted in a
> fraction of a carrier cycle with real AM signals which noise. This is why I
> have contacted this group. From my investigations, the usual signal
> processing techniques do not work. Simple diode/mixer low pass filtering
> cannot be used because the filter requires more than a fraction of a
> carrier cycle to extract the modulation. FFT has the same problem.
>
> William

Fine time resolution can be achieved with a signal with wide bandwidth 
(which is pretty much what we've been saying for a while regarding 
information content and randomness).  If the AM signal is not 
synchronous to the carrier phase then time resolution much finer than a 
carrier period can be achieved.  I don't think that's where your problem 
lies, though.



>
>
>> On 3/25/2010 8:45 AM, WWalker wrote:
>>> Eric,
>>>
>>> A narrow band AM signal propagates undistorted and faster than light in
> the
>>> nearfield and reduces to the speed of light as it goes into the
> farfield. A
>>> pulse distorts in the nearfield and and realigns as it goes into the
>>> farfield. When the pulse is distorted, one cannot say anything about
> the
>>> speed of the pulse. To transmit information faster than light one must
> use
>>> narrowband signals like AM and transmitt and receive them in the
> nearfield
>>> of the carrier.
>>>
>>> It is true that a real dipole anntena has filter characteristics. The
>>> simulation I presented is an idealized dipole like an oscillating
> electron
>>> which does not have filter characteristics. In an experiment with real
>>> antennas one would have to subtract out the phase shifts due to the
>>> antennas filter characteristics so that one only sees the time delay
>>> behavior of the propagating fields.
>>>
>>> The signals I used in my simulation are a changing modulation over the
> time
>>> window of analysis. The changing modulation does not repeat over this
>>> window. It is true that they are created from deterministic signals.
>>> Bassically I generated a beat frequency modulation which has a carrier
> and
>>> a modulation frequency. Provided the window of analysis is smaller than
> a
>>> modulation time period, the modulation pattern does not repeat. After a
>>> modulation period the patern repeats again. I chose this type of signal
>>> because it is a changing pattern which eventually repeats, enabling me
> to
>>> trigger it in a real experient and also enabling me to do time
> averaging
>>> which will help a lot with improving the SNR if a experimental signal.
>>
>> The period of the signal isn't necessarily consequential, the fact that
>> it is not random is.  The point being that the signal you are using is
>> not suitable for measuring propagation at the resolution you're
>> interested in because it is a deterministic signal.   Even when there's
>> a component that is randomly changing with time it is easy to get fooled
>> by the nature of narrowband signals, and that was pretty much a big
>> point of Andor's paper.  I'm beginning to see why he chose the title
>> that he did.
>>
>>> When perform an autocorrelation of the modulation I used in my
> simulation,
>>> I see a triangular signal with a peak at the time of the analysis time
>>> window, indicating that the signal has no obserable repetition pattern
> of
>>> the this time. Only after I increase the analysis time window greater
> than
>>> the modulation period do I get significant sidelobes in the
> autocorrelation
>>> signal, indicating that the pattern repeats after each multiple of a
>>> modulation cycle.
>>
>> Again, how many periods you observe isn't what matters when the signal
>> is completely deterministic.  You're just observing the same,
>> informationally-static signal over different periods of time.  That
>> tells you little to nothing about the propagation of information.
>>
>>
>>> Of course I can create a random narrowband signal as was done in the
> OpAmp
>>> resonator paper: http://www.dsprelated.com/showarticle/54.php
>>> modulate it with a carrier and pass it through a dipole system, and
> finally
>>> extract the modulation, and compare it to a light propagated signal. If
>>> this is done you get exactly the same answer as I showed in my
> simulation.
>>> But if this technique is used than I can not use time averagiing to
> improve
>>> SNR which is need for detection of the modulation in real experimental
>>> signals. I have perfomed this random modulation simulation using
> Agilent
>>> Vee Pro software which is not possible to show here in text format. But
> I
>>> can try to describe it. I took a 100V random generator and sent the
> signal
>>> through a 50 MHz cutoff (fc), 6th order LPF with the following transfer
>>> function [1/(j(f/fc)+1)^6]. Then I multiplied it with a 500MHz carrier
> and
>>> sent it though a light speed propagating transfer function [e^(ikr)]
> and
>>> though the magnetic component of a electric dipole transfer function
>>> [e^(ikr)*(-kr-i)]. Finally I extracted the modulation envelopes of the
>>> tranmitted signal, light speed signal, and the dipole signal. To
> extract
>>> the envelopes I used squared the signal and then passed it through a
> 300MHz
>>> cutoff (fc), 12th order LPF with the following transfer function
>>> [1/(j(f/fc)+1)^12].
>>
>> Again, be careful even when there is a random component, as the narrow
>> band predictability of the signal can easily appear to be accelerated
>> propagation, as Andor demonstrated.   He hit it spot-on, IMHO, by
>> showing a pulse appear to arrive before the stimulus, but then
>> demonstrated that interrupting the source proved that the signal was, in
>> fact, causal after all.  A train of such pulses can be modulated with a
>> random component, but if one isn't extremely careful I'd think it'd be
>> pretty easy to make an incorrect conclusion about what was propagation
>> and what was just typical band-limited predictability.
>>
>> This is why I suggested interrupting your transmit signal at some point,
>> perhaps even at a zero crossing, because it may help to see what's
>> really going on.
>>
>> Your burden of proof is large, and it appears to me that you're not at
>> all very far down the road of sufficiency if you're not addressing these
>> issues head on.  Your continued use of a completely deterministic signal
>> for propagation measurements suggests to me that you've not been
>> measuring what you think you have been.
>>
>> I think you want a signal with enough entropy to justify your claims.
>> The signals you're using are nearly entropy-free.  I suspect there's a
>> relationship between signal entropy and the sort of resolution or
>> confidence you can have in a propagation measurement, but I don't know
>> what it might be off the top of my head.   If you had such a
>> demonstrated relationship you may then be able to show whether or not
>> you were really measuring propagation rather than prediction.
>> Otherwise folks like me (and I'm guessing some of the others here who've
>> spoken up and plenty of others like them) are going to continue to point
>> to the known prediction mechanisms as the far more likely explanation of
>> your results rather than grandiose claims of exceeding c.
>>
>>
>>
>>
>>
>>
>>> William
>>>
>>>
>>>> On 3/24/2010 4:56 PM, WWalker wrote:
>>>>> Eric,
>>>>>
>>>>> The dicontinuity of a pulse from a dipole source propagates at light
>>> speed,
>>>>> but the pulse distorts in the nearfield because it is wideband and
> the
>>>>> dispersion is not linear over the bandwidth of the signal. In the
>>> farfield
>>>>> the pulse realigns and propagates with out distortion at the speed of
>>>>> light. Group speed only has meaning if the signal does not distort as
>>> it
>>>>> propagates. So in the nearfield one can not say anything about the
>>>>> propagation speed of a pulse, but in the farfield the pulse clearly
>>>>> propagates undistorted at the speed of light.
>>>>
>>>> In previous posts you seemed to be claiming that the signal was
>>>> propagating faster than c in the near field.   Now you are saying "in
>>>> the nearfield one can not say anything about the propagation speed of
> a
>>>> pulse".  Can you clear up my confusion?   Are you claiming that there
> is
>>>> a region over which the signal propagates at a speed faster than c?
>>>>
>>>>> Only a narrowband signal propagates without distortion in both the
>>>>> nearfield and farfield from a dipole source. This is because the
>>> dispersion
>>>>> is not very nonlinear and can approximately linear over the bandwidth
> of
>>> a
>>>>> narrow band signal. Since the signal does not distort as it
> propagates
>>> then
>>>>> the group speed can be clearly observed.
>>>>
>>>>> The dipole system is not a filter. Wave propagation from a dipole
>>> source
>>>>> occurs in free space. There is not a medium which can filter out or
>>> change
>>>>> frequency components in a signal. The transfer functions of a dipole
>>> source
>>>>> simply decribes how the field components propagate.
>>>>
>>>> Dipoles are actually bandpass filters with a center frequency
> determined
>>>> by the length of the dipole as related to the wavelength of the
> carrier.
>>>>     Efficiency drops off significantly as the wavelength changes
>>>> substantially from the resonant length of the dipole.
>>>>
>>>>> Clearly simple narrowband AM radio transmission contains information.
>>> Just
>>>>> turn on an AM radio and listen. The information is known to be the
>>>>> modulation envelope of the AM signal. My simmulation simply shows
> that
>>> in
>>>>> the nearfield, the modulation envelope arrives earlier in time (dt)
> than
>>> a
>>>>> light speed propagated modulation (dt=0.08/fc), where fc is the
> carrier
>>>>> frequency.
>>>>
>>>> You seem to be unclear on the definition of "information" in this
>>>> context, and I think it's a big part of what's tripping you up.  The
> AM
>>>> radio broadcast signals you like to cite contain "information" because
>>>> they're modulated with a significant degree of random components.   As
>>>> has been pointed out previously, you may not have an adequate grasp on
>>>> what "random" means in this context, either.   So not getting
>>>> "information" and "random" right in this context may be the root of
>>>> what's led you astray.
>>>>
>>>> I shall point out again, as have others, that if you introduce some
>>>> genuine randomness (i.e., information) into your test signals you will
>>>> be able to demonstrate whether your claims of propagation faster than
> c
>>>> are true (if you are, in fact, still claiming that) or not.  Until
> then
>>>> I will again point out that your current test signals are NOT adequate
>>>> for that purpose.   Jerry pointed out long ago that your signals are
>>>> completely deterministic, and, therefore, not random.   Anybody with
> the
>>>> most basic knowledge of trigonometry can predict the exact value of
> the
>>>> signal at ANY point in the future given the initial parameters.  In
>>>> fact, your simulation can do that, too!  And it is!  That proves
>>>> absolutely nothing and does not support the claims that you have been
>>>> making of propagation faster than the speed of light.
>>>>
>>>> The same can not be said of a typical AM radio broadcast signal
> because
>>>> those do, in fact, have random components due to the changing nature
> of
>>>> the modulating signals.   The parameters of your modulating signals,
> the
>>>> amplitudes and relative phases of the initial input sinusoids, do not
>>>> change and therefore carry no information beyond those initial
>>>> parameters.  This means that a short window of observation is all that
>>>> is needed to extract what little information there is in the signal,
>>>> because there isn't any additional information added beyond that.
>>>> After that, no information is carried in the signal other than "no
>>>> change", and there certainly aren't any random components by which to
>>>> measure information propagation.
>>>>
>>>> A static '1' has minimal information, and observing it's state past
>>>> reliable detection of the initial transition into that state will
> reveal
>>>> no additional information by which propagation speed can be measured.
>>>> This is the case with your test signals as well.  The relative phases
> of
>>>> the signals are NOT indicative of propagation velocity.  You need to
> add
>>>> a perturbation of some sort, i.e., new modulating information, and
>>>> detect the propagation velocity of that new modulated information.
>>>> Until you do that it appears to me that you have no basis on which to
>>>> make claims of any unexpected phenomena.
>>>>
>>>>
>>>>
>>>>>
>>>>> William
>>>>>
>>>>>
>>>>>> On 3/24/2010 8:04 AM, WWalker wrote:
>>>>>>> Eric,
>>>>>>>
>>>>>>> There is fundamental difference between a phase shift caused by a
>>>>> filter
>>>>>>> and a time delay caused by wave propagation across a region of
> space.
>>>>> The
>>>>>>> Op Amp filter circuit is simply phase shifting the harmonic
>>> components
>>>>> of
>>>>>>> the signal such that the overall signal appears like it has arrived
>>>>> before
>>>>>>> it was transmitted. The circuit is not really predicting the signal
>>> it
>>>>> is
>>>>>>> only phase shifting it.
>>>>>>
>>>>>> Yes, this is fundamental.  Still, of note, is that the way to
>>>>>> distinguish between such a phase shift and an increase in
> propagation
>>>>>> velocity is to introduce a perturbation, as Andor did, so that it
> can
>>> be
>>>>>> seen whether the prediction is due to negative group delay or
>>>>>> accelerated propagation.   Andor's experiment is revealing in that
> it
>>>>>> offers a method to demonstrate that what appears to be accelerated
>>>>>> propagation is really narrow-band prediction.   As far as I can tell
>>> you
>>>>>> have not yet done the same, and are instead claiming the rather
>>>>>> grandiose explanation of virtual photons (which cannot be used in
> the
>>>>>> context of information transfer) and propagation faster than the
> speed
>>>>>> of light.
>>>>>>
>>>>>> It could be cleared up pretty easily by demonstrating actual
>>> information
>>>>>> transmission, but it seems to me that you resort to hand waving
>>> instead.
>>>>>>
>>>>>>> In my system, the time delay of the signal is completely due to
> wave
>>>>>>> propagation across space. It is not a filter.
>>>>>>
>>>>>> You have not yet demonstrated that.
>>>>>>
>>>>>>> The simulation I presented simply shows the time delay of the
>>> modulation
>>>>> of
>>>>>>> an AM signal transmission between two nearfield dipole antennas. If
>>> you
>>>>>>> zoom in one can see that the modulations arrive earlier than a
> light
>>>>>>> propagated signal.
>>>>>>
>>>>>> Except that with the signals you're using the propagation cannot be
>>>>>> distinguished from a phase shift.   Again, the point of Andor's
> paper
>>> is
>>>>>> that there's a simple way to distinguish the difference.   Until you
>>> do
>>>>>> so you should not expect much respect of your grandiose claims when
>>>>>> there's a much simpler explanation.
>>>>>>
>>>>>>> This is not phase velocity, this is group velocity i.e. time delay
> of
>>>>> the
>>>>>>> envelope.
>>>>>>>
>>>>>>> William
>>>>>>
>>>>>> It doesn't matter which it is or whether the conditions are linear
> so
>>>>>> that they're the same, you haven't demonstrated that the propagation
>>> has
>>>>>> accelerated.   Either demonstrate some actual information
> transmission
>>>>>> or expect people to keep pushing back on you.  You have a high
> burden
>>> of
>>>>>> proof to make the claims that you're making, but you don't seem to
>>> want
>>>>>> to offer anything substantial.
>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> On 3/23/2010 6:06 PM, WWalker wrote:
>>>>>>>>> Eric,
>>>>>>>>>
>>>>>>>>> Interesting article, but I don't see how it applies to my system.
>>> The
>>>>>>>>> system described in the paper is a bandpass filter in a feedback
>>>>> loop,
>>>>>>>>> where the bandpass filter phase function is altered by the
>>> feedback.
>>>>>>> The
>>>>>>>>> feedback forces the endpoints of the phase to zero, creating
>>> regions
>>>>> of
>>>>>>>>> possitive slope, which yield negative group delays for narrow
> band
>>>>>>> signals.
>>>>>>>>> This causes narrow band signals at the output of the circuit
> appear
>>>>> to
>>>>>>>>> arrive earlier than signals at the input of the circuit. Because
>>> the
>>>>>>>>> information in the signals is slightly redundant, the circuit is
>>> able
>>>>>>> to
>>>>>>>>> reconstruct future parts of the signal from the present part of
> the
>>>>>>>>> signal.
>>>>>>>>
>>>>>>>> Snipped context to allow bottom-posting.
>>>>>>>>
>>>>>>>> Feedback is not necessary to produce negative group delay.
> Here's
>>>>>>>> another example with a passive notch filter that exhibits negative
>>>>> group
>>>>>>>> delay.
>>>>>>>>
>>>>>>>> http://www.radiolab.com.au/DesignFile/DN004.pdf
>>>>>>>>
>>>>>>>> It doesn't matter what's inside a black box if it has a negative
>>> group
>>>>>>>> delay characteristic if the transfer function is LTI.   Whether
>>>>> there's
>>>>>>>> feedback or not in the implementation is inconsequential.
> Consider
>>>>>>>> that the passive notch filter could also be implemented as an
> active
>>>>>>>> circuit with feedback, and if the transfer functions are
> equivalent
>>>>> they
>>>>>>>> are functionally equivalent.   This is fundamental.  I don't think
>>> the
>>>>>>>> feedback has anything to do with it.
>>>>>>>>
>>>>>>>> You're argument on the redundancy, though, is spot-on.   Note
> that,
>>> as
>>>>>>>> others have already pointed out multiple times, the signals you're
>>>>> using
>>>>>>>> in your experiment are HIGHLY redundant, so much so that they
> carry
>>>>>>>> almost no information.   These signals are therefore not suitable
>>> for
>>>>>>>> proving anything about information propagation.
>>>>>>>>
>>>>>>>>
>>>>>>>>> First of all, this is a circuit which alters the phase function
>>> with
>>>>>>>>> respect to time and not space, as it is in my system. The phase
>>>>> function
>>>>>>> in
>>>>>>>>> the circuit is not due to wave propagaton, where mine is.
>>>>>>>>
>>>>>>>> As far as I've been able to tell, your evidence is based on a
>>>>>>>> simulation, in which case dimensionalities are abstractions.   You
>>> are
>>>>>>>> not performing anything in either time or space, you're performing
> a
>>>>>>>> numerical simulation.  Space-time transforms are not at all
> unusual
>>>>> and
>>>>>>>> it is likely that a substitution is easily performed.  Nothing has
>>>>>>>> propagated in your simulation in either time or space.
>>>>>>>>
>>>>>>>>> Secondly,unlike the circuit, my system is causal. The recieved
>>> signal
>>>>> in
>>>>>>> my
>>>>>>>>> system arrives after the signal is transmitted. It just travels
>>>>> faster
>>>>>>> than
>>>>>>>>> light.
>>>>>>>>
>>>>>>>> Uh, the circuit is causal.  That was the point.
>>>>>>>>
>>>>>>>> You have not demonstrated that your system is causal or not
> causal.
>>>>>>>> That cannot be concluded using the waveforms you show in your
> paper
>>>>> due
>>>>>>>> to the high determinism and narrow band characteristics.
>>>>>>>>
>>>>>>>>> Thirdly, the negative group delay in the circuit was accomplished
>>> by
>>>>>>> using
>>>>>>>>> feedback which does not exist in my system.
>>>>>>>>
>>>>>>>> As I stated above, this is inconsequential.
>>>>>>>>
>>>>>>>>
>>>>>>>>> Information (modulations) are clearly transmitted using
> narrowband
>>> AM
>>>>>>> radio
>>>>>>>>> communication, just listen to an AM radio. The simulation I
>>> presented
>>>>>>>>> simply shows that random AM modulations arrive undistorted across
>>>>> space,
>>>>>>> in
>>>>>>>>> the nearfield, earlier than a light speed propagated signal.
>>>>>>>>
>>>>>>>> Your simulation does not demonstrate that.  Turn the signal off,
>>> even
>>>>> at
>>>>>>>> a zero crossing if you want to minimize perturbations, and see
> what
>>>>>>> happens.
>>>>>>>>
>>>>>>>>> Signal purturbations can not be used to measure the signal
>>>>> propagation
>>>>>>> in
>>>>>>>>> the nearfield because they distort in the nearfield, and group
>>> speed
>>>>> has
>>>>>>> no
>>>>>>>>> meaning if the signal distorts as it propagates.
>>>>>>>>>
>>>>>>>>> William
>>>>>>>>
>>>>>>>> If you cannot use a perturbation (i.e., information transmission)
> to
>>>>>>>> measure signal propagation then you cannot demonstrate the speed
> of
>>>>>>>> information propagation.   Until you can actually demonstrate
>>>>> something
>>>>>>>> other than phase velocity (which is NOT information transmission
> and
>>>>>>>> many here have acknowledged can be faster than c, as do I), then
> you
>>>>>>>> cannot make the conclusions that you are claiming.
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Eric Jacobsen
>>>>>>>> Minister of Algorithms
>>>>>>>> Abineau Communications
>>>>>>>> http://www.abineau.com
>>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Eric Jacobsen
>>>>>> Minister of Algorithms
>>>>>> Abineau Communications
>>>>>> http://www.abineau.com
>>>>>>
>>>>
>>>>
>>>> --
>>>> Eric Jacobsen
>>>> Minister of Algorithms
>>>> Abineau Communications
>>>> http://www.abineau.com
>>>>
>>
>>
>> --
>> Eric Jacobsen
>> Minister of Algorithms
>> Abineau Communications
>> http://www.abineau.com
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

On 24 Mar, 01:20, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
> On 3/23/2010 4:51 PM, Rune Allnor wrote:

> You sim doesn't run very well under my version of Octave, but the bit
> about the phase velocity on oblique angles is fundamental.

It's wave physics 101, be it in the context of acustic, optical
or microwave EM waveguides. Anyone who have taken an intro class
on either topic would recognize the phase velocity at oblique
angles.

>=A0 I haven't
> been able to sort out what WW is doing well enough to know for certain

You don't need to. It suffices to recognize what he does *not*
do, know or understand:

- He has no concept of phase fronts in wave fields
- He has no concept of Poynting's vector, that describes
  energy flux in EM wave fields,

  http://en.wikipedia.org/wiki/Poynting_vector

- He has no concept of "information" as a random process

  http://en.wikipedia.org/wiki/Information_entropy

  (I am sure somebody can come up with a link to Shannons's
  result that information =3D=3D energy)
- He has no concept of the monochromatic signal's *irrelevane*
  in transmission systems
- He has no concept of "AM modulation" for information-carrying
  signals of non-vanishing bandwidth
- He has no concept of the role of transient cahnges in
  information-carrying signals

No matter what apporach one investigates this sham from, one
can shoot it down using little more than entry-level basics.
In fact, it's a feat that one person can consistently do
so many, so basic blunders in every possiblefield or craft
he attempts to employ. And if I get the timings right, he has
persisted in this manner for almost a decade and a half.

A truly remarkable intellectual capacity, if nothing else.

Rune

Rune Allnor wrote:
> On 24 Mar, 01:20, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
>> On 3/23/2010 4:51 PM, Rune Allnor wrote:
> 
>> You sim doesn't run very well under my version of Octave, but the bit
>> about the phase velocity on oblique angles is fundamental.

I don't think the illusion is based on obliquity. Walter is wrong about 
faster-than-light signaling, but he's not naive. Close in, the near 
field predominates, but it fades faster than the far field, so there's a 
transition as the distance from the antenna increases. There's a net 
shift of pi/2 when shifting between the two field components. That's 
subtle enough to take someone in without engendering too much embarrassment.

   ...

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 26 Mar, 22:02, Jerry Avins <j...@ieee.org> wrote:
> Rune Allnor wrote:
> > On 24 Mar, 01:20, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
> >> On 3/23/2010 4:51 PM, Rune Allnor wrote:
>
> >> You sim doesn't run very well under my version of Octave, but the bit
> >> about the phase velocity on oblique angles is fundamental.
>
> I don't think the illusion is based on obliquity. Walter is wrong about
> faster-than-light signaling, but he's not naive.

Agreed. He seems to be far worse off than that.

> Close in, the near
> field predominates, but it fades faster than the far field, so there's a
> transition as the distance from the antenna increases. There's a net
> shift of pi/2 when shifting between the two field components. That's
> subtle enough to take someone in without engendering too much embarrassment.

There are two main factors at play in the near field:

- Interefernce between the fields emanated by the two monopoles
- The evanecent components of the plane-wave expansion of
  the spherical wave field.

The former is wave theory 101 material; the latter is wave
theory 102.

The fundamental effect is intereference: The dipole is a
superporsition of monopoles (wave theory 101). There is
nothing else at play. The definition of a dipole, is
a pair of monopoles that emits the same signal at the
same time - possibly with different scalar weights.
Again, WT 101.

Th edefinition of 'near field' is the space where wave
form arrive forms arrive from the two dipoles at notably
different directions - WT 101. The analytic study of this
interefernce, is a mess, for a number reasons:

1) The analytic study of spherical Bessel functions is messy
2) Converting the Bessels to plane waves is even more messy
3) By 1) and 2) it becomes difficult to decomose the field
   at (x,y,z) in terms of components arriving form the
   individual monopoles
4) Since no one decomoposes the wavefield in said way,
   no one obtain the detailed understanding of what
   exactly goes on.

So there are no convenient ways to find out the detailed
behaviour of the field. But there is no need to, since the
basic mechanism is so simple: Interference, possibly
combined with oblique observation.

Again, except for the plane-wave representation of the
spherical Bessel functions, all of this is wave theory 101.

Rune

On 3/26/2010 2:31 PM, Rune Allnor wrote:
> On 26 Mar, 22:02, Jerry Avins<j...@ieee.org>  wrote:
>> Rune Allnor wrote:
>>> On 24 Mar, 01:20, Eric Jacobsen<eric.jacob...@ieee.org>  wrote:
>>>> On 3/23/2010 4:51 PM, Rune Allnor wrote:
>>
>>>> You sim doesn't run very well under my version of Octave, but the bit
>>>> about the phase velocity on oblique angles is fundamental.
>>
>> I don't think the illusion is based on obliquity. Walter is wrong about
>> faster-than-light signaling, but he's not naive.
>
> Agreed. He seems to be far worse off than that.
>
>> Close in, the near
>> field predominates, but it fades faster than the far field, so there's a
>> transition as the distance from the antenna increases. There's a net
>> shift of pi/2 when shifting between the two field components. That's
>> subtle enough to take someone in without engendering too much embarrassment.
>
> There are two main factors at play in the near field:
>
> - Interefernce between the fields emanated by the two monopoles
> - The evanecent components of the plane-wave expansion of
>    the spherical wave field.
>
> The former is wave theory 101 material; the latter is wave
> theory 102.
>
> The fundamental effect is intereference: The dipole is a
> superporsition of monopoles (wave theory 101). There is
> nothing else at play. The definition of a dipole, is
> a pair of monopoles that emits the same signal at the
> same time - possibly with different scalar weights.
> Again, WT 101.
>
> Th edefinition of 'near field' is the space where wave
> form arrive forms arrive from the two dipoles at notably
> different directions - WT 101. The analytic study of this
> interefernce, is a mess, for a number reasons:
>
> 1) The analytic study of spherical Bessel functions is messy
> 2) Converting the Bessels to plane waves is even more messy
> 3) By 1) and 2) it becomes difficult to decomose the field
>     at (x,y,z) in terms of components arriving form the
>     individual monopoles
> 4) Since no one decomoposes the wavefield in said way,
>     no one obtain the detailed understanding of what
>     exactly goes on.
>
> So there are no convenient ways to find out the detailed
> behaviour of the field. But there is no need to, since the
> basic mechanism is so simple: Interference, possibly
> combined with oblique observation.
>
> Again, except for the plane-wave representation of the
> spherical Bessel functions, all of this is wave theory 101.
>
> Rune

That also explains why it can be simulated numerically.  If there was 
something funky going on, like virtual photons, one would think a 
numerical simulation wouldn't show it because it wouldn't be included in 
the math.   The first yellow flag here was that numerical simulations 
were being used to demonstrate the effect of something unknown and 
unexplained.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric,

Figure 2 in the Sten paper clearly shows that the pulse distorts in the
nearfield making it impossible to say anything about the speed of the
pulse. Only a narrowband signal will propagate undistorted from the
nearfield to the farfield.

Regarding your comments on adding nonharmonic signals to create the
modultion, even Mathematica cannot curvefit to the known equation. Check it
for yourself. The Mathematica curvefitting code is below. Note there are
many parrameters to fit and it is not able to do it, so it is not so easy!


fn = Ao Cos[Wo*t + phc]*(Cm + A1*Cos[W1*t + phm1] + A2*Cos[W2*t + phm2])

Curvefit = 
 FindFit[points, fn, {Ao, A1, A2, phc, phm1, phm2, Cm, Wo, W1, W2}, t]

Never the less, we do not need to discuss this any further because the same
superluminal behavior is observed in my newest simulation which uses a
random noise generator with a low pass filter. This latest test signal is
clearly nondeterministic. 


----------------Mathematica Curvefitting Program---------------- 
Gen Sig
AM = Cos[Wc*t + 0.1]*(3 + Am1*Cos[Wm1*t + 0.2] + Am2*Cos[Wm2*t + 0.2])
Wc = 2 Pi fc; Wm1 = 2 Pi fm1; Wm2 = 2 Pi fm2;
Am1 = 1; Am2 = 1.7;
fc = 500*10^6; fm1 = 50*10^6; fm2 = 22.7*10^6;
Amp = 1; DT = 100*10^(-9); T = 100*10^(-9);
Envelope = (3 + Am1*Cos[Wm1*t + 0.2] + Am2*Cos[Wm2*t + 0.2]);
Plot[{Envelope, AM}, {t, 0, DT}]
Plot[AM, {t, 0, T}, PlotPoints\:f0ae2000]
points = Table[{t, N[AM]}, {t, 0, DT, T/2000}];
plotpoints = ListPlot[points, PlotStyle -> PointSize[0.016/2]]
Curve Fit Sig
fn = Ao Cos[
   Wo*t + phc]*(Cm + A1*Cos[W1*t + phm1] + A2*Cos[W2*t + phm2])
Curvefit = 
 FindFit[points, fn, {Ao, A1, A2, phc, phm1, phm2, Cm, Wo, W1, W2}, t]
Compare Sig with Curve Fit Sig
PlotCurve = Plot[fn /. Curvefit, {t, 0, T}, PlotPoints -> 10];
Show[plotpoints, PlotCurve]
DetEnvelope = 
 3 + A1*Cos[Wm1*t + phm1] + A2*Cos[Wm2*t + phm2] /. Curvefit
Plot[DetEnvelope, {t, 0, DT}]
Plot[{DetEnvelope, AM}, {t, 0, DT}]
Plot[{Envelope, DetEnvelope}, {t, 0, DT}]
-----------------End Mathematica Curvefitting Program------------

Regading your comment that the dipole is a filter, it is not a filter. The
dipole system has a dispersion curve. A signal can be decomposed into
frequency components and when the signal is sent through a dipole each
frequency component experiences a different wave phase speed. If the wave
phase speed is different for different frequencies then the signal will
distort as it propagates, as it does for a wideband pulse. If the wave
phase speed is the same for all the frequency components of the signal,
then the signal will not distort as it propagates. This is what happens for
a narrow band AM signal. 

Regarding your comment on Andor's paper, the circuit is not predicting the
signal, it is just phase shifting it. The filter has a phase curve and each
frequency component of the signal is being phase shifted. If each frequency
component is phase shifted the same amount, then the signal will phase
shift undistorted. This is very different from a time delay due to wave
propagation, as is observed in the dipole system.

William


>On 3/25/2010 9:01 AM, WWalker wrote:
>> Jerry,
>>
>> I have tested real dipole antennas using a RF Network analyser and
after
>> compensating for the electrical filter characteristics of the antenna,
I
>> get the nonlinear dispersion curves shown in my paper. The nonlinear
>> dispersion is a real observable and measureable phenomina.
>>
>> Here is another paper that presents an NEC RF numerical analysis on a
>> dipole and shows the nonlinear nearfield dispersion is real and
>> observable:
>> http://ceta.mit.edu/pier/pier.php?paper=0505121
>>
>> William
>
>FWIW, a quick read of that paper seems to support exactly what Jerry and 
>I and others have been saying.  The phase response of the near-field 
>makes it behave similarly to a filter with negative group delay.  The 
>author even points this out about Fig. 2b, where the pulse appears to 
>accelerate.
>
>It is not at all hard to believe that dispersion that leads to apparent 
>non-causal behavior in passive or active filters could also seem to 
>appear as signal propagation faster than c.
>
>
>>> Eric Jacobsen wrote:
>>>
>>>    ...
>>>
>>>> Dipoles are actually bandpass filters with a center frequency
determined
>>
>>>> by the length of the dipole as related to the wavelength of the
carrier.
>>
>>>>    Efficiency drops off significantly as the wavelength changes
>>>> substantially from the resonant length of the dipole.
>>>
>>> Herein lies the fallacy that is at the heart of what I see as self
>>> deception. Eric describes a real dipole, while Walter's simulation is
>>> constructed around an ideal one. An ideal dipole is a limit as the
>>> length of a real dipole goes to zero while the power it radiates
remains
>>> constant. (Compare to an impulse: a pulse whose width goes to zero
while
>>> its area remains constant.) Such abstractions are useful for brushing
>>> aside irrelevant details while retaining relevant relationships. They
>>> remain useful only so long as the ignored details remain irrelevant.
For
>>> example, it is inappropriate to inquire about the voltage gradient
along
>>> an ideal diode.
>>>
>>> An example might clarify the limit of an abstraction's utility.
Consider
>>> a ball bouncing on a flat surface, such that every bounce's duration
is
>>> 90% of that of the previous bounce. The ball is initially dropped from
>>> such a height that the first bounce lasts exactly one second. It is
not
>>> difficult to show that the ball will come to rest after ten seconds.
In
>>> that interval, how many times will the ball bounce?
>>>
>>> In dipoles, the extents of the near field are related to the
dimensions
>>> of the dipole. We can expect an ideal dipole, having zero length, to
>>> have a very peculiar calculated near field.
>>>
>>>    ...
>>>
>>> Jerry
>>> --
>>> Discovery consists of seeing what everybody has seen, and thinking
what
>>> nobody has thought.    .. Albert Szent-Gyorgi
>>>
�����������������������������������������������������������������������
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Rune,

It is true that physicists like to decompose field components into charge
displacement, velocity, and accelertion components (Ref. Eq 5 of Sten
paper) but this is simply a Taylor's expansion approximation to a composite
field term. The expansion terms are not physically real, they are just
mathematical representations enabling one to model the system. The Taylor
expansion is needed to solve the Vector potentials of a dipole.
Refer to p.6 of my paper: http://xxx.lanl.gov/pdf/physics/0603240

William
    

>Rune Allnor wrote:
>> On 24 Mar, 01:20, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
>>> On 3/23/2010 4:51 PM, Rune Allnor wrote:
>> 
>>> You sim doesn't run very well under my version of Octave, but the bit
>>> about the phase velocity on oblique angles is fundamental.
>
>I don't think the illusion is based on obliquity. Walter is wrong about 
>faster-than-light signaling, but he's not naive. Close in, the near 
>field predominates, but it fades faster than the far field, so there's a 
>transition as the distance from the antenna increases. There's a net 
>shift of pi/2 when shifting between the two field components. That's 
>subtle enough to take someone in without engendering too much
embarrassment.
>
>   ...
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

WWalker <william.walker@n_o_s_p_a_m.imtek.de> wrote:
 
> It is true that physicists like to decompose field components into charge
> displacement, velocity, and accelertion components (Ref. Eq 5 of Sten
> paper) but this is simply a Taylor's expansion approximation to a composite
> field term. The expansion terms are not physically real, they are just
> mathematical representations enabling one to model the system. The Taylor
> expansion is needed to solve the Vector potentials of a dipole.
> Refer to p.6 of my paper: http://xxx.lanl.gov/pdf/physics/0603240

I believe Feynman has a good description of this, too.
(It should be vol. 2 of Feynman Lectures on Physics.)

One non-obvious part of the expansion has a name something like
retarded field.  If you look at the field from a charge moving
at a constant velocity, the field is radial from the position
of the charge.  That is, the current position, not the position
d/c (distance/speed of light) ago.  (Remembering from some years
ago, so I might not have it exactly right.)  

So, if I remember it, the first term (you call displacement)
gives the field for where the charge was, the second (velocity)
corrects that so you see where the charge is.  Acceleration doesn't
apply for constant velocity.  If the charge does change velocity,
you see the field for where it would have been until the effect
of the third term arrives.

Then Feynman goes on to explain the third term, and its importance
for communication.  That is the one you see in far field, at least
in the case of neutral systems like radio transmitters.

-- glen

Rune, 

Are the insults really necessary! This is a serious discussion and the
concepts are not easy. It is a complex system. I garentee no one knows
exactly what is going on in this system. Insults and ridicule are simply
childish and unbecomming in an intelectual discussion. 

Regarding your two monopole model, this is a mathematical approximation.
Remember this is modelling an oscillating electron, which is not really
composed of two charges spaced a fixed length apart. This is just a
mathematical model which enables one to calculate the fields at a  distance
much larger than oscilation amplitude of the oscillating charge. As you get
near the electron, this model breaks down and is not valid. To determine
the filds near a dipole, one can use the Liénard-Wiechert potentials.  

William



>On 26 Mar, 22:02, Jerry Avins <j...@ieee.org> wrote:
>> Rune Allnor wrote:
>> > On 24 Mar, 01:20, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
>> >> On 3/23/2010 4:51 PM, Rune Allnor wrote:
>>
>> >> You sim doesn't run very well under my version of Octave, but the
bit
>> >> about the phase velocity on oblique angles is fundamental.
>>
>> I don't think the illusion is based on obliquity. Walter is wrong about
>> faster-than-light signaling, but he's not naive.
>
>Agreed. He seems to be far worse off than that.
>
>> Close in, the near
>> field predominates, but it fades faster than the far field, so there's
a
>> transition as the distance from the antenna increases. There's a net
>> shift of pi/2 when shifting between the two field components. That's
>> subtle enough to take someone in without engendering too much
embarrassment.
>
>There are two main factors at play in the near field:
>
>- Interefernce between the fields emanated by the two monopoles
>- The evanecent components of the plane-wave expansion of
>  the spherical wave field.
>
>The former is wave theory 101 material; the latter is wave
>theory 102.
>
>The fundamental effect is intereference: The dipole is a
>superporsition of monopoles (wave theory 101). There is
>nothing else at play. The definition of a dipole, is
>a pair of monopoles that emits the same signal at the
>same time - possibly with different scalar weights.
>Again, WT 101.
>
>Th edefinition of 'near field' is the space where wave
>form arrive forms arrive from the two dipoles at notably
>different directions - WT 101. The analytic study of this
>interefernce, is a mess, for a number reasons:
>
>1) The analytic study of spherical Bessel functions is messy
>2) Converting the Bessels to plane waves is even more messy
>3) By 1) and 2) it becomes difficult to decomose the field
>   at (x,y,z) in terms of components arriving form the
>   individual monopoles
>4) Since no one decomoposes the wavefield in said way,
>   no one obtain the detailed understanding of what
>   exactly goes on.
>
>So there are no convenient ways to find out the detailed
>behaviour of the field. But there is no need to, since the
>basic mechanism is so simple: Interference, possibly
>combined with oblique observation.
>
>Again, except for the plane-wave representation of the
>spherical Bessel functions, all of this is wave theory 101.
>
>Rune
>

Eric,

It is known that Maxwell Equations have quantum mechnaics built into it, so
the fields generated by an oscillating electron (dipole source) will be the
same if it is calculated using Maxwell's equations or using Quantum
mechanics.

The numerical simulation I presented is completly predicted by
Electromagnetic theory. Refer to my paper:
http://xxx.lanl.gov/pdf/physics/0603240  

William


>On 3/26/2010 2:31 PM, Rune Allnor wrote:
>> On 26 Mar, 22:02, Jerry Avins<j...@ieee.org>  wrote:
>>> Rune Allnor wrote:
>>>> On 24 Mar, 01:20, Eric Jacobsen<eric.jacob...@ieee.org>  wrote:
>>>>> On 3/23/2010 4:51 PM, Rune Allnor wrote:
>>>
>>>>> You sim doesn't run very well under my version of Octave, but the
bit
>>>>> about the phase velocity on oblique angles is fundamental.
>>>
>>> I don't think the illusion is based on obliquity. Walter is wrong
about
>>> faster-than-light signaling, but he's not naive.
>>
>> Agreed. He seems to be far worse off than that.
>>
>>> Close in, the near
>>> field predominates, but it fades faster than the far field, so there's
a
>>> transition as the distance from the antenna increases. There's a net
>>> shift of pi/2 when shifting between the two field components. That's
>>> subtle enough to take someone in without engendering too much
embarrassment.
>>
>> There are two main factors at play in the near field:
>>
>> - Interefernce between the fields emanated by the two monopoles
>> - The evanecent components of the plane-wave expansion of
>>    the spherical wave field.
>>
>> The former is wave theory 101 material; the latter is wave
>> theory 102.
>>
>> The fundamental effect is intereference: The dipole is a
>> superporsition of monopoles (wave theory 101). There is
>> nothing else at play. The definition of a dipole, is
>> a pair of monopoles that emits the same signal at the
>> same time - possibly with different scalar weights.
>> Again, WT 101.
>>
>> Th edefinition of 'near field' is the space where wave
>> form arrive forms arrive from the two dipoles at notably
>> different directions - WT 101. The analytic study of this
>> interefernce, is a mess, for a number reasons:
>>
>> 1) The analytic study of spherical Bessel functions is messy
>> 2) Converting the Bessels to plane waves is even more messy
>> 3) By 1) and 2) it becomes difficult to decomose the field
>>     at (x,y,z) in terms of components arriving form the
>>     individual monopoles
>> 4) Since no one decomoposes the wavefield in said way,
>>     no one obtain the detailed understanding of what
>>     exactly goes on.
>>
>> So there are no convenient ways to find out the detailed
>> behaviour of the field. But there is no need to, since the
>> basic mechanism is so simple: Interference, possibly
>> combined with oblique observation.
>>
>> Again, except for the plane-wave representation of the
>> spherical Bessel functions, all of this is wave theory 101.
>>
>> Rune
>
>That also explains why it can be simulated numerically.  If there was 
>something funky going on, like virtual photons, one would think a 
>numerical simulation wouldn't show it because it wouldn't be included in 
>the math.   The first yellow flag here was that numerical simulations 
>were being used to demonstrate the effect of something unknown and 
>unexplained.
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 3/26/2010 4:42 PM, WWalker wrote:
> Eric,
>
> Figure 2 in the Sten paper clearly shows that the pulse distorts in the
> nearfield making it impossible to say anything about the speed of the
> pulse. Only a narrowband signal will propagate undistorted from the
> nearfield to the farfield.

I asked about this previously and you did not respond.  If you cannot 
say anything about the speed of the pulse in the near field due to 
"distortion", how can you claim that it is faster than c?

The "distortion" appears to be understood according to the Sten paper, 
and not inconsistent with group delay effects.

> Regarding your comments on adding nonharmonic signals to create the
> modultion, even Mathematica cannot curvefit to the known equation. Check it
> for yourself. The Mathematica curvefitting code is below. Note there are
> many parrameters to fit and it is not able to do it, so it is not so easy!

I don't have Mathematica, and don't have any intent to use it, so I 
don't really care about its shortcomings.

> fn = Ao Cos[Wo*t + phc]*(Cm + A1*Cos[W1*t + phm1] + A2*Cos[W2*t + phm2])
>
> Curvefit =
>   FindFit[points, fn, {Ao, A1, A2, phc, phm1, phm2, Cm, Wo, W1, W2}, t]
>
> Never the less, we do not need to discuss this any further because the same
> superluminal behavior is observed in my newest simulation which uses a
> random noise generator with a low pass filter. This latest test signal is
> clearly nondeterministic.

That's an improvement, but probably still not sufficient.   It seems to 
me you're not paying attention to advice here.

Good luck.


>
>
> ----------------Mathematica Curvefitting Program----------------
> Gen Sig
> AM = Cos[Wc*t + 0.1]*(3 + Am1*Cos[Wm1*t + 0.2] + Am2*Cos[Wm2*t + 0.2])
> Wc = 2 Pi fc; Wm1 = 2 Pi fm1; Wm2 = 2 Pi fm2;
> Am1 = 1; Am2 = 1.7;
> fc = 500*10^6; fm1 = 50*10^6; fm2 = 22.7*10^6;
> Amp = 1; DT = 100*10^(-9); T = 100*10^(-9);
> Envelope = (3 + Am1*Cos[Wm1*t + 0.2] + Am2*Cos[Wm2*t + 0.2]);
> Plot[{Envelope, AM}, {t, 0, DT}]
> Plot[AM, {t, 0, T}, PlotPoints\:f0ae2000]
> points = Table[{t, N[AM]}, {t, 0, DT, T/2000}];
> plotpoints = ListPlot[points, PlotStyle ->  PointSize[0.016/2]]
> Curve Fit Sig
> fn = Ao Cos[
>     Wo*t + phc]*(Cm + A1*Cos[W1*t + phm1] + A2*Cos[W2*t + phm2])
> Curvefit =
>   FindFit[points, fn, {Ao, A1, A2, phc, phm1, phm2, Cm, Wo, W1, W2}, t]
> Compare Sig with Curve Fit Sig
> PlotCurve = Plot[fn /. Curvefit, {t, 0, T}, PlotPoints ->  10];
> Show[plotpoints, PlotCurve]
> DetEnvelope =
>   3 + A1*Cos[Wm1*t + phm1] + A2*Cos[Wm2*t + phm2] /. Curvefit
> Plot[DetEnvelope, {t, 0, DT}]
> Plot[{DetEnvelope, AM}, {t, 0, DT}]
> Plot[{Envelope, DetEnvelope}, {t, 0, DT}]
> -----------------End Mathematica Curvefitting Program------------
>
> Regading your comment that the dipole is a filter, it is not a filter. The
> dipole system has a dispersion curve. A signal can be decomposed into
> frequency components and when the signal is sent through a dipole each
> frequency component experiences a different wave phase speed. If the wave
> phase speed is different for different frequencies then the signal will
> distort as it propagates, as it does for a wideband pulse. If the wave
> phase speed is the same for all the frequency components of the signal,
> then the signal will not distort as it propagates. This is what happens for
> a narrow band AM signal.
>
> Regarding your comment on Andor's paper, the circuit is not predicting the
> signal, it is just phase shifting it. The filter has a phase curve and each
> frequency component of the signal is being phase shifted. If each frequency
> component is phase shifted the same amount, then the signal will phase
> shift undistorted. This is very different from a time delay due to wave
> propagation, as is observed in the dipole system.
>
> William
>
>
>> On 3/25/2010 9:01 AM, WWalker wrote:
>>> Jerry,
>>>
>>> I have tested real dipole antennas using a RF Network analyser and
> after
>>> compensating for the electrical filter characteristics of the antenna,
> I
>>> get the nonlinear dispersion curves shown in my paper. The nonlinear
>>> dispersion is a real observable and measureable phenomina.
>>>
>>> Here is another paper that presents an NEC RF numerical analysis on a
>>> dipole and shows the nonlinear nearfield dispersion is real and
>>> observable:
>>> http://ceta.mit.edu/pier/pier.php?paper=0505121
>>>
>>> William
>>
>> FWIW, a quick read of that paper seems to support exactly what Jerry and
>> I and others have been saying.  The phase response of the near-field
>> makes it behave similarly to a filter with negative group delay.  The
>> author even points this out about Fig. 2b, where the pulse appears to
>> accelerate.
>>
>> It is not at all hard to believe that dispersion that leads to apparent
>> non-causal behavior in passive or active filters could also seem to
>> appear as signal propagation faster than c.
>>
>>
>>>> Eric Jacobsen wrote:
>>>>
>>>>     ...
>>>>
>>>>> Dipoles are actually bandpass filters with a center frequency
> determined
>>>
>>>>> by the length of the dipole as related to the wavelength of the
> carrier.
>>>
>>>>>     Efficiency drops off significantly as the wavelength changes
>>>>> substantially from the resonant length of the dipole.
>>>>
>>>> Herein lies the fallacy that is at the heart of what I see as self
>>>> deception. Eric describes a real dipole, while Walter's simulation is
>>>> constructed around an ideal one. An ideal dipole is a limit as the
>>>> length of a real dipole goes to zero while the power it radiates
> remains
>>>> constant. (Compare to an impulse: a pulse whose width goes to zero
> while
>>>> its area remains constant.) Such abstractions are useful for brushing
>>>> aside irrelevant details while retaining relevant relationships. They
>>>> remain useful only so long as the ignored details remain irrelevant.
> For
>>>> example, it is inappropriate to inquire about the voltage gradient
> along
>>>> an ideal diode.
>>>>
>>>> An example might clarify the limit of an abstraction's utility.
> Consider
>>>> a ball bouncing on a flat surface, such that every bounce's duration
> is
>>>> 90% of that of the previous bounce. The ball is initially dropped from
>>>> such a height that the first bounce lasts exactly one second. It is
> not
>>>> difficult to show that the ball will come to rest after ten seconds.
> In
>>>> that interval, how many times will the ball bounce?
>>>>
>>>> In dipoles, the extents of the near field are related to the
> dimensions
>>>> of the dipole. We can expect an ideal dipole, having zero length, to
>>>> have a very peculiar calculated near field.
>>>>
>>>>     ...
>>>>
>>>> Jerry
>>>> --
>>>> Discovery consists of seeing what everybody has seen, and thinking
> what
>>>> nobody has thought.    .. Albert Szent-Gyorgi
>>>>
> �����������������������������������������������������������������������
>>>>
>>
>>
>> --
>> Eric Jacobsen
>> Minister of Algorithms
>> Abineau Communications
>> http://www.abineau.com
>>


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric,

Since a pulse distorts in the nearfield, one can not determin it's group
speed in the nearfield. But if you take the same pulse and send it through
a low pass filter, mix it with a carrier, and send it though a dipole you
get the same superluminal results. Because the filtered pulse is narrow
band, it propagates undistorted and arrives sooner than a light propagated
pulse.

I have done a Vee Pro simulation and it clearly shows this. In this program
I used a pulse with the following characteristics: 1Hz Freq, 50ns pulse
width, 10ns rise and fall time, 1V amplitude. the Lowpass filter had the
following characteristics: 50MHz cutoff frequency (fc), 6th order, Transfer
function: 1/(j(f/fc)+1)^6. Then I multiplied this narrowbanded signal with
a 500MHz carrier and sent it though a light speed propagating transfer
function [e^(ikr)] and though the magnetic component of a electric dipole
transfer function [e^(ikr)*(-kr-i)]. Finally I extracted the modulation
envelopes of the tranmitted signal, light speed signal, and the dipole
signal. To extract the envelopes I squared the signal and then passed it
through a 300MHz cutoff (fc), 12th order LPF with the following transfer
function [1/(j(f/fc)+1)^12]. The pulse envelope from the dipole arrives
0.16ns earlier than the light speed propagated pulse. This corresponds
exactly with theoretical expectations (0.08/fc=0.16ns).

I think perhaps this is the evidence you have all been looking for. 

William


>On 3/26/2010 4:42 PM, WWalker wrote:
>> Eric,
>>
>> Figure 2 in the Sten paper clearly shows that the pulse distorts in the
>> nearfield making it impossible to say anything about the speed of the
>> pulse. Only a narrowband signal will propagate undistorted from the
>> nearfield to the farfield.
>
>I asked about this previously and you did not respond.  If you cannot 
>say anything about the speed of the pulse in the near field due to 
>"distortion", how can you claim that it is faster than c?
>
>The "distortion" appears to be understood according to the Sten paper, 
>and not inconsistent with group delay effects.
>
>> Regarding your comments on adding nonharmonic signals to create the
>> modultion, even Mathematica cannot curvefit to the known equation. Check
it
>> for yourself. The Mathematica curvefitting code is below. Note there
are
>> many parrameters to fit and it is not able to do it, so it is not so
easy!
>
>I don't have Mathematica, and don't have any intent to use it, so I 
>don't really care about its shortcomings.
>
>> fn = Ao Cos[Wo*t + phc]*(Cm + A1*Cos[W1*t + phm1] + A2*Cos[W2*t +
phm2])
>>
>> Curvefit =
>>   FindFit[points, fn, {Ao, A1, A2, phc, phm1, phm2, Cm, Wo, W1, W2}, t]
>>
>> Never the less, we do not need to discuss this any further because the
same
>> superluminal behavior is observed in my newest simulation which uses a
>> random noise generator with a low pass filter. This latest test signal
is
>> clearly nondeterministic.
>
>That's an improvement, but probably still not sufficient.   It seems to 
>me you're not paying attention to advice here.
>
>Good luck.
>
>
>>
>>
>> ----------------Mathematica Curvefitting Program----------------
>> Gen Sig
>> AM = Cos[Wc*t + 0.1]*(3 + Am1*Cos[Wm1*t + 0.2] + Am2*Cos[Wm2*t + 0.2])
>> Wc = 2 Pi fc; Wm1 = 2 Pi fm1; Wm2 = 2 Pi fm2;
>> Am1 = 1; Am2 = 1.7;
>> fc = 500*10^6; fm1 = 50*10^6; fm2 = 22.7*10^6;
>> Amp = 1; DT = 100*10^(-9); T = 100*10^(-9);
>> Envelope = (3 + Am1*Cos[Wm1*t + 0.2] + Am2*Cos[Wm2*t + 0.2]);
>> Plot[{Envelope, AM}, {t, 0, DT}]
>> Plot[AM, {t, 0, T}, PlotPoints\:f0ae2000]
>> points = Table[{t, N[AM]}, {t, 0, DT, T/2000}];
>> plotpoints = ListPlot[points, PlotStyle ->  PointSize[0.016/2]]
>> Curve Fit Sig
>> fn = Ao Cos[
>>     Wo*t + phc]*(Cm + A1*Cos[W1*t + phm1] + A2*Cos[W2*t + phm2])
>> Curvefit =
>>   FindFit[points, fn, {Ao, A1, A2, phc, phm1, phm2, Cm, Wo, W1, W2}, t]
>> Compare Sig with Curve Fit Sig
>> PlotCurve = Plot[fn /. Curvefit, {t, 0, T}, PlotPoints ->  10];
>> Show[plotpoints, PlotCurve]
>> DetEnvelope =
>>   3 + A1*Cos[Wm1*t + phm1] + A2*Cos[Wm2*t + phm2] /. Curvefit
>> Plot[DetEnvelope, {t, 0, DT}]
>> Plot[{DetEnvelope, AM}, {t, 0, DT}]
>> Plot[{Envelope, DetEnvelope}, {t, 0, DT}]
>> -----------------End Mathematica Curvefitting Program------------
>>
>> Regading your comment that the dipole is a filter, it is not a filter.
The
>> dipole system has a dispersion curve. A signal can be decomposed into
>> frequency components and when the signal is sent through a dipole each
>> frequency component experiences a different wave phase speed. If the
wave
>> phase speed is different for different frequencies then the signal will
>> distort as it propagates, as it does for a wideband pulse. If the wave
>> phase speed is the same for all the frequency components of the signal,
>> then the signal will not distort as it propagates. This is what happens
for
>> a narrow band AM signal.
>>
>> Regarding your comment on Andor's paper, the circuit is not predicting
the
>> signal, it is just phase shifting it. The filter has a phase curve and
each
>> frequency component of the signal is being phase shifted. If each
frequency
>> component is phase shifted the same amount, then the signal will phase
>> shift undistorted. This is very different from a time delay due to wave
>> propagation, as is observed in the dipole system.
>>
>> William
>>
>>
>>> On 3/25/2010 9:01 AM, WWalker wrote:
>>>> Jerry,
>>>>
>>>> I have tested real dipole antennas using a RF Network analyser and
>> after
>>>> compensating for the electrical filter characteristics of the
antenna,
>> I
>>>> get the nonlinear dispersion curves shown in my paper. The nonlinear
>>>> dispersion is a real observable and measureable phenomina.
>>>>
>>>> Here is another paper that presents an NEC RF numerical analysis on a
>>>> dipole and shows the nonlinear nearfield dispersion is real and
>>>> observable:
>>>> http://ceta.mit.edu/pier/pier.php?paper=0505121
>>>>
>>>> William
>>>
>>> FWIW, a quick read of that paper seems to support exactly what Jerry
and
>>> I and others have been saying.  The phase response of the near-field
>>> makes it behave similarly to a filter with negative group delay.  The
>>> author even points this out about Fig. 2b, where the pulse appears to
>>> accelerate.
>>>
>>> It is not at all hard to believe that dispersion that leads to
apparent
>>> non-causal behavior in passive or active filters could also seem to
>>> appear as signal propagation faster than c.
>>>
>>>
>>>>> Eric Jacobsen wrote:
>>>>>
>>>>>     ...
>>>>>
>>>>>> Dipoles are actually bandpass filters with a center frequency
>> determined
>>>>
>>>>>> by the length of the dipole as related to the wavelength of the
>> carrier.
>>>>
>>>>>>     Efficiency drops off significantly as the wavelength changes
>>>>>> substantially from the resonant length of the dipole.
>>>>>
>>>>> Herein lies the fallacy that is at the heart of what I see as self
>>>>> deception. Eric describes a real dipole, while Walter's simulation
is
>>>>> constructed around an ideal one. An ideal dipole is a limit as the
>>>>> length of a real dipole goes to zero while the power it radiates
>> remains
>>>>> constant. (Compare to an impulse: a pulse whose width goes to zero
>> while
>>>>> its area remains constant.) Such abstractions are useful for
brushing
>>>>> aside irrelevant details while retaining relevant relationships.
They
>>>>> remain useful only so long as the ignored details remain irrelevant.
>> For
>>>>> example, it is inappropriate to inquire about the voltage gradient
>> along
>>>>> an ideal diode.
>>>>>
>>>>> An example might clarify the limit of an abstraction's utility.
>> Consider
>>>>> a ball bouncing on a flat surface, such that every bounce's duration
>> is
>>>>> 90% of that of the previous bounce. The ball is initially dropped
from
>>>>> such a height that the first bounce lasts exactly one second. It is
>> not
>>>>> difficult to show that the ball will come to rest after ten seconds.
>> In
>>>>> that interval, how many times will the ball bounce?
>>>>>
>>>>> In dipoles, the extents of the near field are related to the
>> dimensions
>>>>> of the dipole. We can expect an ideal dipole, having zero length, to
>>>>> have a very peculiar calculated near field.
>>>>>
>>>>>     ...
>>>>>
>>>>> Jerry
>>>>> --
>>>>> Discovery consists of seeing what everybody has seen, and thinking
>> what
>>>>> nobody has thought.    .. Albert Szent-Gyorgi
>>>>>
>>
�����������������������������������������������������������������������
>>>>>
>>>
>>>
>>> --
>>> Eric Jacobsen
>>> Minister of Algorithms
>>> Abineau Communications
>>> http://www.abineau.com
>>>
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 3/27/2010 3:47 AM, WWalker wrote:
> Eric,
>
> Since a pulse distorts in the nearfield, one can not determin it's group
> speed in the nearfield. But if you take the same pulse and send it through
> a low pass filter, mix it with a carrier, and send it though a dipole you
> get the same superluminal results. Because the filtered pulse is narrow
> band, it propagates undistorted and arrives sooner than a light propagated
> pulse.

I'm not following this argument, especially the last statement.


> I have done a Vee Pro simulation and it clearly shows this. In this program
> I used a pulse with the following characteristics: 1Hz Freq, 50ns pulse
> width, 10ns rise and fall time, 1V amplitude. the Lowpass filter had the
> following characteristics: 50MHz cutoff frequency (fc), 6th order, Transfer
> function: 1/(j(f/fc)+1)^6. Then I multiplied this narrowbanded signal with
> a 500MHz carrier and sent it though a light speed propagating transfer
> function [e^(ikr)] and though the magnetic component of a electric dipole
> transfer function [e^(ikr)*(-kr-i)]. Finally I extracted the modulation
> envelopes of the tranmitted signal, light speed signal, and the dipole
> signal. To extract the envelopes I squared the signal and then passed it
> through a 300MHz cutoff (fc), 12th order LPF with the following transfer
> function [1/(j(f/fc)+1)^12]. The pulse envelope from the dipole arrives
> 0.16ns earlier than the light speed propagated pulse. This corresponds
> exactly with theoretical expectations (0.08/fc=0.16ns).
>
> I think perhaps this is the evidence you have all been looking for.
>
> William

Although I probably shouldn't be, I was thinking about this a bit more 
and wanted to add some thoughts.

Although the following is certainly not a rigorous analysis, in general 
as the signal bandwidth goes up the time resolution one can achieve in 
correlation measurements gets smaller.  The information update rate for 
typical comm systems is the symbol period, Ts, and generally Ts = 1/BW 
where BW is the 3dB signal bandwidth.  It is possible to resolve time 
more finely than Ts and synchronization systems have to do this to 
recover the symbols, but a reasonable benchmark for how fast information 
is updating is Ts = 1/BW.  I think it is arguable that if one wants to 
measure how fast information is propagating with very fine time 
resolution one needs to use a signal with a very wide bandwidth. 
Otherwise one risks measuring a phase offset due to phenomena like 
negative group delay rather than accelerated information propagation.

You said:

 > The pulse envelope from the dipole arrives
 > 0.16ns earlier than the light speed propagated pulse. This corresponds
 > exactly with theoretical expectations (0.08/fc=0.16ns).

What theory creates an expectation that the signal propagates faster 
than light?  I don't know of any.

Since you've filtered your signal to 50 MHz BW there will be no 
significant frequency components with periods shorter than 20ns.  You're 
claiming that a time difference of 0.16ns (or 1/125th of the length of 
the smallest period in the signal) is a difference in information 
propagation.  I think it's far more likely to be a phase shift due to 
the dispersion (as shown in the Sten paper), since that is only 360/125 
= 2.88 degrees of phase advance.   A signal experiencing 2.88 degrees of 
phase advance through a dispersive medium is far more believable than 
propagation faster than light.  This is what I've been saying, what 
Andor's blog demonstrates, and what my reading of the Sten paper indicates.

As mentioned long ago, I think a good experiment would be to interrupt 
the input signal at some point, perhaps even the modulated signal at a 
carrier zero crossing.   The propagation of the interruption (which has 
infinite bandwidth if it's a hard stop) should be revealing.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric Jacobsen wrote:

> As mentioned long ago, I think a good experiment would be to interrupt 
> the input signal at some point, perhaps even the modulated signal at a 
> carrier zero crossing.   The propagation of the interruption (which has 
> infinite bandwidth if it's a hard stop) should be revealing.

Interesting question. What should be a good narrowband test signal to 
demonstrate the information propagation speed in dispersive media?
Obviously it should not be an eigenfunction of linear system; i.e. 
sinusoids and exponentials are not suitable.
I suggest windowed sinc or RRC pulse modulated BPSK.
But, you may have to put the equalization filter into the picture as well.

Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

Eric Jacobsen <eric.jacobsen@ieee.org> wrote:
(snip)
 
> Although the following is certainly not a rigorous analysis, in general 
> as the signal bandwidth goes up the time resolution one can achieve in 
> correlation measurements gets smaller.  The information update rate for 
> typical comm systems is the symbol period, Ts, and generally Ts = 1/BW 
> where BW is the 3dB signal bandwidth.  It is possible to resolve time 
> more finely than Ts and synchronization systems have to do this to 
> recover the symbols, but a reasonable benchmark for how fast information 
> is updating is Ts = 1/BW.  I think it is arguable that if one wants to 
> measure how fast information is propagating with very fine time 
> resolution one needs to use a signal with a very wide bandwidth. 
> Otherwise one risks measuring a phase offset due to phenomena like 
> negative group delay rather than accelerated information propagation.

I agree.  I was indirectly mentioning this a few days ago, with
the suggestion of very low bandwidth, and so low information
transmission rates.  Also, for efficient communication, you have
to make good use of the bandwidth that you do have.  There should
be signal components throughout the whole bandwidth.  As Jerry was
mentioning, with a single sinewave modulating the carrier there
is pretty much zero information flowing.  
 
> You said:
 
> > The pulse envelope from the dipole arrives
> > 0.16ns earlier than the light speed propagated pulse. This corresponds
> > exactly with theoretical expectations (0.08/fc=0.16ns).
 
> What theory creates an expectation that the signal propagates faster 
> than light?  I don't know of any.
 
> Since you've filtered your signal to 50 MHz BW there will be no 
> significant frequency components with periods shorter than 20ns.  You're 
> claiming that a time difference of 0.16ns (or 1/125th of the length of 
> the smallest period in the signal) is a difference in information 
> propagation.  

With enough averaging, it can be done.  The average should be over
a wide distribution of input signals, though. 
 
> I think it's far more likely to be a phase shift due to 
> the dispersion (as shown in the Sten paper), since that is only 360/125 
> = 2.88 degrees of phase advance.   A signal experiencing 2.88 degrees of 
> phase advance through a dispersive medium is far more believable than 
> propagation faster than light.  This is what I've been saying, what 
> Andor's blog demonstrates, and what my reading of the Sten paper indicates.

This was done optically some years ago, but the experimenters
knew exactly what was happening.  If you have a narrow bandwidth
system, then it is pretty much resonant at that frequency.  As the
beginning of the Gaussian envelope wave comes through, it excites
the resonant system and generates an output with a peak earlier than
you would expect due to the velocity of light.  If you change the
shape of the pulse, then the resulting time is different.
I don't know the reference anymore, though.
 
> As mentioned long ago, I think a good experiment would be to interrupt 
> the input signal at some point, perhaps even the modulated signal at a 
> carrier zero crossing.   The propagation of the interruption (which has 
> infinite bandwidth if it's a hard stop) should be revealing.

Well, you can't really do that with a narrow band system.  
The modulation has to be within the bandwidth, which limits how
fast you can change the signal.  

-- glen

On 3/27/2010 10:59 AM, glen herrmannsfeldt wrote:
> Eric Jacobsen<eric.jacobsen@ieee.org>  wrote:
> (snip)
>
>> Although the following is certainly not a rigorous analysis, in general
>> as the signal bandwidth goes up the time resolution one can achieve in
>> correlation measurements gets smaller.  The information update rate for
>> typical comm systems is the symbol period, Ts, and generally Ts = 1/BW
>> where BW is the 3dB signal bandwidth.  It is possible to resolve time
>> more finely than Ts and synchronization systems have to do this to
>> recover the symbols, but a reasonable benchmark for how fast information
>> is updating is Ts = 1/BW.  I think it is arguable that if one wants to
>> measure how fast information is propagating with very fine time
>> resolution one needs to use a signal with a very wide bandwidth.
>> Otherwise one risks measuring a phase offset due to phenomena like
>> negative group delay rather than accelerated information propagation.
>
> I agree.  I was indirectly mentioning this a few days ago, with
> the suggestion of very low bandwidth, and so low information
> transmission rates.  Also, for efficient communication, you have
> to make good use of the bandwidth that you do have.  There should
> be signal components throughout the whole bandwidth.  As Jerry was
> mentioning, with a single sinewave modulating the carrier there
> is pretty much zero information flowing.
>
>> You said:
>
>>> The pulse envelope from the dipole arrives
>>> 0.16ns earlier than the light speed propagated pulse. This corresponds
>>> exactly with theoretical expectations (0.08/fc=0.16ns).
>
>> What theory creates an expectation that the signal propagates faster
>> than light?  I don't know of any.
>
>> Since you've filtered your signal to 50 MHz BW there will be no
>> significant frequency components with periods shorter than 20ns.  You're
>> claiming that a time difference of 0.16ns (or 1/125th of the length of
>> the smallest period in the signal) is a difference in information
>> propagation.
>
> With enough averaging, it can be done.  The average should be over
> a wide distribution of input signals, though.
>
>> I think it's far more likely to be a phase shift due to
>> the dispersion (as shown in the Sten paper), since that is only 360/125
>> = 2.88 degrees of phase advance.   A signal experiencing 2.88 degrees of
>> phase advance through a dispersive medium is far more believable than
>> propagation faster than light.  This is what I've been saying, what
>> Andor's blog demonstrates, and what my reading of the Sten paper indicates.
>
> This was done optically some years ago, but the experimenters
> knew exactly what was happening.  If you have a narrow bandwidth
> system, then it is pretty much resonant at that frequency.  As the
> beginning of the Gaussian envelope wave comes through, it excites
> the resonant system and generates an output with a peak earlier than
> you would expect due to the velocity of light.  If you change the
> shape of the pulse, then the resulting time is different.
> I don't know the reference anymore, though.
>
>> As mentioned long ago, I think a good experiment would be to interrupt
>> the input signal at some point, perhaps even the modulated signal at a
>> carrier zero crossing.   The propagation of the interruption (which has
>> infinite bandwidth if it's a hard stop) should be revealing.
>
> Well, you can't really do that with a narrow band system.
> The modulation has to be within the bandwidth, which limits how
> fast you can change the signal.
>
> -- glen

Yes, but turning the signal off abruptly at the input to the antenna 
provide the widest bandwidth stimulus that you're going to get, and 
therefore, I think, a good reference signal.   An wideband impulse at 
the input to the antenna would be better, but some don't seem to like 
doing this analysis with a pulse.   The Sten paper did, and showed the 
dispersion with it.  That seems logical to me.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

On 3/27/2010 10:05 AM, Vladimir Vassilevsky wrote:
>
>
> Eric Jacobsen wrote:
>
>> As mentioned long ago, I think a good experiment would be to interrupt
>> the input signal at some point, perhaps even the modulated signal at a
>> carrier zero crossing. The propagation of the interruption (which has
>> infinite bandwidth if it's a hard stop) should be revealing.
>
> Interesting question. What should be a good narrowband test signal to
> demonstrate the information propagation speed in dispersive media?
> Obviously it should not be an eigenfunction of linear system; i.e.
> sinusoids and exponentials are not suitable.
> I suggest windowed sinc or RRC pulse modulated BPSK.
> But, you may have to put the equalization filter into the picture as well.
>
> Vladimir Vassilevsky
> DSP and Mixed Signal Design Consultant
> http://www.abvolt.com

Yeah, it's an interesting problem.  I now see why Ander referred to his 
blog article as "pouring oil in the fire and causing yet more 
confusion."  I've not thought this out completely, but I'm starting to 
think you just can't get there with a narrowband signal if you want good 
time resolution and you don't want to get fooled by group delay hijinks.

Clearly an impulse is a preferrable stimulus, and any filtering in the 
system will degrade that to a sinc of some sort, so starting with a 
windowed sinc isn't a bad idea.

Likewise a BPSK signal, with the highest symbol rate possible, and then 
compare the phases of the transmit and recovered symbol clocks, would 
work.  The time resolution would be no better than the clock jitter 
window, but if the symbol rate was high enough that could be made pretty 
small.  But, as you mention, whether or not the signal was equalized 
would affect the result as the clock may lock somewhere other than the 
center of the eye.

Tough problem.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

WWalker wrote:


> I have done a Vee Pro simulation and it clearly shows this.

Walter,

Let's keep the things simple. Can you please try the following:

 From initial zero state, apply the 500 MHz sine wave to your system at 
t=0. Look when the output will be different from zero.


Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

Eric Jacobsen wrote:

> On 3/27/2010 10:05 AM, Vladimir Vassilevsky wrote:
> 
>>
>>
>> Eric Jacobsen wrote:
>>
>>> As mentioned long ago, I think a good experiment would be to interrupt
>>> the input signal at some point, perhaps even the modulated signal at a
>>> carrier zero crossing. The propagation of the interruption (which has
>>> infinite bandwidth if it's a hard stop) should be revealing.
>>
>>
>> Interesting question. What should be a good narrowband test signal to
>> demonstrate the information propagation speed in dispersive media?
>> Obviously it should not be an eigenfunction of linear system; i.e.
>> sinusoids and exponentials are not suitable.
>> I suggest windowed sinc or RRC pulse modulated BPSK.
>> But, you may have to put the equalization filter into the picture as 

> 
> Yeah, it's an interesting problem.  I now see why Ander referred to his 
> blog article as "pouring oil in the fire and causing yet more 
> confusion."  I've not thought this out completely, but I'm starting to 
> think you just can't get there with a narrowband signal if you want good 
> time resolution and you don't want to get fooled by group delay hijinks.
> 
> Clearly an impulse is a preferrable stimulus, and any filtering in the 
> system will degrade that to a sinc of some sort, so starting with a 
> windowed sinc isn't a bad idea.
> 
> Likewise a BPSK signal, with the highest symbol rate possible, and then 
> compare the phases of the transmit and recovered symbol clocks, would 
> work.  The time resolution would be no better than the clock jitter 
> window, but if the symbol rate was high enough that could be made pretty 
> small.  But, as you mention, whether or not the signal was equalized 
> would affect the result as the clock may lock somewhere other than the 
> center of the eye.
> 
> Tough problem.

I am afraid that it could not be possible to get any conclusive proof if 
a "minimal" demodulation procedure (which actually retrieves data) is 
not included into the picture. Therefore equalizers and such.


Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

On 3/27/2010 11:52 AM, Vladimir Vassilevsky wrote:
>
>
> Eric Jacobsen wrote:
>
>> On 3/27/2010 10:05 AM, Vladimir Vassilevsky wrote:
>>
>>>
>>>
>>> Eric Jacobsen wrote:
>>>
>>>> As mentioned long ago, I think a good experiment would be to interrupt
>>>> the input signal at some point, perhaps even the modulated signal at a
>>>> carrier zero crossing. The propagation of the interruption (which has
>>>> infinite bandwidth if it's a hard stop) should be revealing.
>>>
>>>
>>> Interesting question. What should be a good narrowband test signal to
>>> demonstrate the information propagation speed in dispersive media?
>>> Obviously it should not be an eigenfunction of linear system; i.e.
>>> sinusoids and exponentials are not suitable.
>>> I suggest windowed sinc or RRC pulse modulated BPSK.
>>> But, you may have to put the equalization filter into the picture as
>
>>
>> Yeah, it's an interesting problem. I now see why Ander referred to his
>> blog article as "pouring oil in the fire and causing yet more
>> confusion." I've not thought this out completely, but I'm starting to
>> think you just can't get there with a narrowband signal if you want
>> good time resolution and you don't want to get fooled by group delay
>> hijinks.
>>
>> Clearly an impulse is a preferrable stimulus, and any filtering in the
>> system will degrade that to a sinc of some sort, so starting with a
>> windowed sinc isn't a bad idea.
>>
>> Likewise a BPSK signal, with the highest symbol rate possible, and
>> then compare the phases of the transmit and recovered symbol clocks,
>> would work. The time resolution would be no better than the clock
>> jitter window, but if the symbol rate was high enough that could be
>> made pretty small. But, as you mention, whether or not the signal was
>> equalized would affect the result as the clock may lock somewhere
>> other than the center of the eye.
>>
>> Tough problem.
>
> I am afraid that it could not be possible to get any conclusive proof if
> a "minimal" demodulation procedure (which actually retrieves data) is
> not included into the picture. Therefore equalizers and such.
>
>
> Vladimir Vassilevsky
> DSP and Mixed Signal Design Consultant
> http://www.abvolt.com

Agreed.  But the delay of the trained equalizer had to be then taken 
into account, which means the reference system for the delay comparison 
has to have its equalizer taken into account as well.  It's probably 
do-able, but perhaps not without pitfalls.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Hi Eric,

>On 3/27/2010 10:59 AM, glen herrmannsfeldt wrote:
>> Eric Jacobsen<eric.jacobsen@ieee.org>  wrote:
>> (snip)
>>
>>> Although the following is certainly not a rigorous analysis, in
general
>>> as the signal bandwidth goes up the time resolution one can achieve in
>>> correlation measurements gets smaller.  The information update rate
for
>>> typical comm systems is the symbol period, Ts, and generally Ts = 1/BW
>>> where BW is the 3dB signal bandwidth.  It is possible to resolve time
>>> more finely than Ts and synchronization systems have to do this to
>>> recover the symbols, but a reasonable benchmark for how fast
information
>>> is updating is Ts = 1/BW.  I think it is arguable that if one wants to
>>> measure how fast information is propagating with very fine time
>>> resolution one needs to use a signal with a very wide bandwidth.
>>> Otherwise one risks measuring a phase offset due to phenomena like
>>> negative group delay rather than accelerated information propagation.
>>
>> I agree.  I was indirectly mentioning this a few days ago, with
>> the suggestion of very low bandwidth, and so low information
>> transmission rates.  Also, for efficient communication, you have
>> to make good use of the bandwidth that you do have.  There should
>> be signal components throughout the whole bandwidth.  As Jerry was
>> mentioning, with a single sinewave modulating the carrier there
>> is pretty much zero information flowing.
>>
>>> You said:
>>
>>>> The pulse envelope from the dipole arrives
>>>> 0.16ns earlier than the light speed propagated pulse. This
corresponds
>>>> exactly with theoretical expectations (0.08/fc=0.16ns).
>>
>>> What theory creates an expectation that the signal propagates faster
>>> than light?  I don't know of any.
>>
>>> Since you've filtered your signal to 50 MHz BW there will be no
>>> significant frequency components with periods shorter than 20ns. 
You're
>>> claiming that a time difference of 0.16ns (or 1/125th of the length of
>>> the smallest period in the signal) is a difference in information
>>> propagation.
>>
>> With enough averaging, it can be done.  The average should be over
>> a wide distribution of input signals, though.
>>
>>> I think it's far more likely to be a phase shift due to
>>> the dispersion (as shown in the Sten paper), since that is only
360/125
>>> = 2.88 degrees of phase advance.   A signal experiencing 2.88 degrees
of
>>> phase advance through a dispersive medium is far more believable than
>>> propagation faster than light.  This is what I've been saying, what
>>> Andor's blog demonstrates, and what my reading of the Sten paper
indicates.
>>
>> This was done optically some years ago, but the experimenters
>> knew exactly what was happening.  If you have a narrow bandwidth
>> system, then it is pretty much resonant at that frequency.  As the
>> beginning of the Gaussian envelope wave comes through, it excites
>> the resonant system and generates an output with a peak earlier than
>> you would expect due to the velocity of light.  If you change the
>> shape of the pulse, then the resulting time is different.
>> I don't know the reference anymore, though.
>>
>>> As mentioned long ago, I think a good experiment would be to interrupt
>>> the input signal at some point, perhaps even the modulated signal at a
>>> carrier zero crossing.   The propagation of the interruption (which
has
>>> infinite bandwidth if it's a hard stop) should be revealing.
>>
>> Well, you can't really do that with a narrow band system.
>> The modulation has to be within the bandwidth, which limits how
>> fast you can change the signal.
>>
>> -- glen
>
>Yes, but turning the signal off abruptly at the input to the antenna 
>provide the widest bandwidth stimulus that you're going to get, and 
>therefore, I think, a good reference signal.   An wideband impulse at 
>the input to the antenna would be better, but some don't seem to like 
>doing this analysis with a pulse.   The Sten paper did, and showed the 
>dispersion with it.  That seems logical to me.

I think you are drifting from the point. You have started talking about
things which affect the efficiency of communication. The claim at hand is
merely that a little information can arrive a little earlier than one might
expect. If any sudden, unexpected, perturbation of a clean carrier could be
detected at the receiver faster than you would expect from speed of light
calculations the case would be proven. It only needs to be one completely
unpredictable change of state. Focus only on that.

The effect is just the good old nature of narrow band signals, quite
unrelated from actual communication. Its the same effect that surprises you
(well, most of us) when first studying sampling theory, and you realise
that you can perfectly reconstruct all the subtle detail of a signal from
just 2 real samples or 1 complex sample per cycle at the absolute maximum
bandwidth of the signal. Anything sufficiently narrow band is highly
predictable. That's the only relevant thing here.

Steve

Eric,

I simply mean the dipole pulse arrives indistorted 0.16ns earlier than if
the pulse had propagated at the light speed. I have made an FTP site where
I have uploaded JPG pictures of my simulation results. This should help
make things clearer. Click on the following hyperlink and it will take you
to the folder: LPF_Pulse_Exp . I hope it works.
ftp://REM:signal@132.230.139.154/LPF_Pulse_Exp

Regarding how I calculated the theoretically predicted time difference from
light speed. I used the following arguments: 
1) del_ph = del_kr*dth/dkr, 
   where del_ph is the phase delay of the envelope, del_kr is the 
   spectral width of the signal (Ref the dispersion curve in my paper 
   ph vs kr for the magnetic component of a dipole, Fig 15 on p.13),th is 
the phase, k is the wave vector, r is the propagation distance 


>On 3/27/2010 3:47 AM, WWalker wrote:
>> Eric,
>>
>> Since a pulse distorts in the nearfield, one can not determin it's
group
>> speed in the nearfield. But if you take the same pulse and send it
through
>> a low pass filter, mix it with a carrier, and send it though a dipole
you
>> get the same superluminal results. Because the filtered pulse is narrow
>> band, it propagates undistorted and arrives sooner than a light
propagated
>> pulse.
>
>I'm not following this argument, especially the last statement.
>
>
>> I have done a Vee Pro simulation and it clearly shows this. In this
program
>> I used a pulse with the following characteristics: 1Hz Freq, 50ns pulse
>> width, 10ns rise and fall time, 1V amplitude. the Lowpass filter had
the
>> following characteristics: 50MHz cutoff frequency (fc), 6th order,
Transfer
>> function: 1/(j(f/fc)+1)^6. Then I multiplied this narrowbanded signal
with
>> a 500MHz carrier and sent it though a light speed propagating transfer
>> function [e^(ikr)] and though the magnetic component of a electric
dipole
>> transfer function [e^(ikr)*(-kr-i)]. Finally I extracted the modulation
>> envelopes of the tranmitted signal, light speed signal, and the dipole
>> signal. To extract the envelopes I squared the signal and then passed
it
>> through a 300MHz cutoff (fc), 12th order LPF with the following
transfer
>> function [1/(j(f/fc)+1)^12]. The pulse envelope from the dipole arrives
>> 0.16ns earlier than the light speed propagated pulse. This corresponds
>> exactly with theoretical expectations (0.08/fc=0.16ns).
>>
>> I think perhaps this is the evidence you have all been looking for.
>>
>> William
>
>Although I probably shouldn't be, I was thinking about this a bit more 
>and wanted to add some thoughts.
>
>Although the following is certainly not a rigorous analysis, in general 
>as the signal bandwidth goes up the time resolution one can achieve in 
>correlation measurements gets smaller.  The information update rate for 
>typical comm systems is the symbol period, Ts, and generally Ts = 1/BW 
>where BW is the 3dB signal bandwidth.  It is possible to resolve time 
>more finely than Ts and synchronization systems have to do this to 
>recover the symbols, but a reasonable benchmark for how fast information 
>is updating is Ts = 1/BW.  I think it is arguable that if one wants to 
>measure how fast information is propagating with very fine time 
>resolution one needs to use a signal with a very wide bandwidth. 
>Otherwise one risks measuring a phase offset due to phenomena like 
>negative group delay rather than accelerated information propagation.
>
>You said:
>
> > The pulse envelope from the dipole arrives
> > 0.16ns earlier than the light speed propagated pulse. This corresponds
> > exactly with theoretical expectations (0.08/fc=0.16ns).
>
>What theory creates an expectation that the signal propagates faster 
>than light?  I don't know of any.
>
>Since you've filtered your signal to 50 MHz BW there will be no 
>significant frequency components with periods shorter than 20ns.  You're 
>claiming that a time difference of 0.16ns (or 1/125th of the length of 
>the smallest period in the signal) is a difference in information 
>propagation.  I think it's far more likely to be a phase shift due to 
>the dispersion (as shown in the Sten paper), since that is only 360/125 
>= 2.88 degrees of phase advance.   A signal experiencing 2.88 degrees of 
>phase advance through a dispersive medium is far more believable than 
>propagation faster than light.  This is what I've been saying, what 
>Andor's blog demonstrates, and what my reading of the Sten paper
indicates.
>
>As mentioned long ago, I think a good experiment would be to interrupt 
>the input signal at some point, perhaps even the modulated signal at a 
>carrier zero crossing.   The propagation of the interruption (which has 
>infinite bandwidth if it's a hard stop) should be revealing.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Eric,

Sorry, the last post I made to you was sent prematurely. I will try again.

I simply mean the dipole pulse arrives indistorted 0.16ns earlier than if
the pulse had propagated at the light speed. I have made an FTP site where
I have uploaded JPG pictures of my simulation results. This should help
make things clearer. Copy and paste the following web address into your
browser and it should take you to the folder: LPF_Pulse_Exp . I hope it
works.

    ftp://REM:signal@132.230.139.154/LPF_Pulse_Exp

Regarding how I calculated the theoretically predicted time difference
from
light speed, refer to the file: Mod_time_delay_from_c_Calc.jpg on the FTP
server at: 

    ftp://REM:signal@132.230.139.154

I am simply using the dispersion curve slope of the magnetic field
component to calculate the time delay of the modulation and then I compare
it to the time delay of a light speed signal. 

Regarding your request that I interrupt the input signal, isn't this what I
did in the LPF Pulse simulation I just posted? The pulse is turned on and
off and both edges arrive ealier than if it propagted at the speed of
light. I guess I could do it without the LPF, but the signal would be
wideband and distort in the nearfield. But the discontinuity in this signal
would appear to propagate at the speed of light, because the high frequency
components comprising the discontinuity would propagate at light speed,
since they are in the farfield. Remember that the speed of the field is
only superluminal in the nearfield and reduces to the speed of light (c) as
the field propagates about a wavelegth from the dipole source, and
continues to propagate at c into the farfield. If the detector is located
at 1/6 carrier wavelength from the dipole, then higher frequency components
with wavelengths a lot shorter than this distance will propagate at speed
c. 


William


>On 3/27/2010 3:47 AM, WWalker wrote:
>> Eric,
>>
>> Since a pulse distorts in the nearfield, one can not determin it's
group
>> speed in the nearfield. But if you take the same pulse and send it
through
>> a low pass filter, mix it with a carrier, and send it though a dipole
you
>> get the same superluminal results. Because the filtered pulse is narrow
>> band, it propagates undistorted and arrives sooner than a light
propagated
>> pulse.
>
>I'm not following this argument, especially the last statement.
>
>
>> I have done a Vee Pro simulation and it clearly shows this. In this
program
>> I used a pulse with the following characteristics: 1Hz Freq, 50ns pulse
>> width, 10ns rise and fall time, 1V amplitude. the Lowpass filter had
the
>> following characteristics: 50MHz cutoff frequency (fc), 6th order,
Transfer
>> function: 1/(j(f/fc)+1)^6. Then I multiplied this narrowbanded signal
with
>> a 500MHz carrier and sent it though a light speed propagating transfer
>> function [e^(ikr)] and though the magnetic component of a electric
dipole
>> transfer function [e^(ikr)*(-kr-i)]. Finally I extracted the modulation
>> envelopes of the tranmitted signal, light speed signal, and the dipole
>> signal. To extract the envelopes I squared the signal and then passed
it
>> through a 300MHz cutoff (fc), 12th order LPF with the following
transfer
>> function [1/(j(f/fc)+1)^12]. The pulse envelope from the dipole arrives
>> 0.16ns earlier than the light speed propagated pulse. This corresponds
>> exactly with theoretical expectations (0.08/fc=0.16ns).
>>
>> I think perhaps this is the evidence you have all been looking for.
>>
>> William
>
>Although I probably shouldn't be, I was thinking about this a bit more 
>and wanted to add some thoughts.
>
>Although the following is certainly not a rigorous analysis, in general 
>as the signal bandwidth goes up the time resolution one can achieve in 
>correlation measurements gets smaller.  The information update rate for 
>typical comm systems is the symbol period, Ts, and generally Ts = 1/BW 
>where BW is the 3dB signal bandwidth.  It is possible to resolve time 
>more finely than Ts and synchronization systems have to do this to 
>recover the symbols, but a reasonable benchmark for how fast information 
>is updating is Ts = 1/BW.  I think it is arguable that if one wants to 
>measure how fast information is propagating with very fine time 
>resolution one needs to use a signal with a very wide bandwidth. 
>Otherwise one risks measuring a phase offset due to phenomena like 
>negative group delay rather than accelerated information propagation.
>
>You said:
>
> > The pulse envelope from the dipole arrives
> > 0.16ns earlier than the light speed propagated pulse. This corresponds
> > exactly with theoretical expectations (0.08/fc=0.16ns).
>
>What theory creates an expectation that the signal propagates faster 
>than light?  I don't know of any.
>
>Since you've filtered your signal to 50 MHz BW there will be no 
>significant frequency components with periods shorter than 20ns.  You're 
>claiming that a time difference of 0.16ns (or 1/125th of the length of 
>the smallest period in the signal) is a difference in information 
>propagation.  I think it's far more likely to be a phase shift due to 
>the dispersion (as shown in the Sten paper), since that is only 360/125 
>= 2.88 degrees of phase advance.   A signal experiencing 2.88 degrees of 
>phase advance through a dispersive medium is far more believable than 
>propagation faster than light.  This is what I've been saying, what 
>Andor's blog demonstrates, and what my reading of the Sten paper
indicates.
>
>As mentioned long ago, I think a good experiment would be to interrupt 
>the input signal at some point, perhaps even the modulated signal at a 
>carrier zero crossing.   The propagation of the interruption (which has 
>infinite bandwidth if it's a hard stop) should be revealing.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 3/27/2010 6:58 PM, WWalker wrote:
> Eric,
>
> Sorry, the last post I made to you was sent prematurely. I will try again.
>
> I simply mean the dipole pulse arrives indistorted 0.16ns earlier than if
> the pulse had propagated at the light speed. I have made an FTP site where
> I have uploaded JPG pictures of my simulation results. This should help
> make things clearer. Copy and paste the following web address into your
> browser and it should take you to the folder: LPF_Pulse_Exp . I hope it
> works.
>
>      ftp://REM:signal@132.230.139.154/LPF_Pulse_Exp

Looks just like Andor's and Sten's plots, which aren't due to 
propagation faster than c.


> Regarding how I calculated the theoretically predicted time difference
> from
> light speed, refer to the file: Mod_time_delay_from_c_Calc.jpg on the FTP
> server at:
>
>      ftp://REM:signal@132.230.139.154
>
> I am simply using the dispersion curve slope of the magnetic field
> component to calculate the time delay of the modulation and then I compare
> it to the time delay of a light speed signal.

Yes.  And how do you distinguish the advance between what is easily 
explained by the effects of negative group delay and the less likely 
explanation of propagation faster than c?   Why do you think the less 
likely explanation is the correct one?   How do you plan to prove that 
the less likely explanation should be accepted?


> Regarding your request that I interrupt the input signal, isn't this what I
> did in the LPF Pulse simulation I just posted? The pulse is turned on and
> off and both edges arrive ealier than if it propagted at the speed of
> light. I guess I could do it without the LPF, but the signal would be
> wideband and distort in the nearfield.

Are you trying to say the nearfield distortion of the wideband component 
would suggest that the propagation is less than or equal to c?   That's 
pretty much the point.

The expectation is that you'll see something similar to Figure 7 in 
Andor's blog article.  You're seeing essentially Figure 5 now, or Fig. 
2a. in Sten's paper.


> But the discontinuity in this signal
> would appear to propagate at the speed of light, because the high frequency
> components comprising the discontinuity would propagate at light speed,
> since they are in the farfield.

Yup.  Which suggests that the signal isn't really propagating faster 
than c after all, it's just dispersing in a way that advances the phase 
and makes it appear to accelerate, like the citations we've been quoting 
over and over and over.

> Remember that the speed of the field is
> only superluminal in the nearfield and reduces to the speed of light (c) as
> the field propagates about a wavelegth from the dipole source, and
> continues to propagate at c into the farfield.

I think most disagree with you here, and think that the pulse just 
distorts in the near field due to the dispersion and advances the phase, 
just like it does in Andor's negative group delay filter and Sten's 
paper.  You're the only one I know of claiming the explanation is 
propagation faster than c.   Everybody else seems to think it's just the 
phase advance due to the dispersion.  Your results appear consistent 
with Andor's and Sten's so far as far as I can tell, but you insist on a 
different explanation.

Eric


> If the detector is located
> at 1/6 carrier wavelength from the dipole, then higher frequency components
> with wavelengths a lot shorter than this distance will propagate at speed
> c.
>
>
> William


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric,

I think you are missing the point. Refering to the Low Pass Filtered Pulse
simulation I posted, the simulation clearly shows that if I transmit a
pulse, the pulse edge arrives sooner than if it had propagated faster than
light. If my detector at the receiving end is threshold detector which is
set to look for anything above the noise level, it will fire earlier than
if the pulse had propagated at light speed. In other words, it shows that
if I push a button launching the narrowband pulse signal and propagate it 
via a dipole to a nearfield receiver with the threshold detector, the
pressed button will be detected sooner than a light propagated signal. This
clearly shows that an action (informaton) in this nearfield dipole system
can be detected faster than light. If this is true than I have proven my
point that information propagtes faster than light in the nearfield of a
dipole.

William


>On 3/27/2010 6:58 PM, WWalker wrote:
>> Eric,
>>
>> Sorry, the last post I made to you was sent prematurely. I will try
again.
>>
>> I simply mean the dipole pulse arrives indistorted 0.16ns earlier than
if
>> the pulse had propagated at the light speed. I have made an FTP site
where
>> I have uploaded JPG pictures of my simulation results. This should help
>> make things clearer. Copy and paste the following web address into your
>> browser and it should take you to the folder: LPF_Pulse_Exp . I hope it
>> works.
>>
>>      ftp://REM:signal@132.230.139.154/LPF_Pulse_Exp
>
>Looks just like Andor's and Sten's plots, which aren't due to 
>propagation faster than c.
>
>
>> Regarding how I calculated the theoretically predicted time difference
>> from
>> light speed, refer to the file: Mod_time_delay_from_c_Calc.jpg on the
FTP
>> server at:
>>
>>      ftp://REM:signal@132.230.139.154
>>
>> I am simply using the dispersion curve slope of the magnetic field
>> component to calculate the time delay of the modulation and then I
compare
>> it to the time delay of a light speed signal.
>
>Yes.  And how do you distinguish the advance between what is easily 
>explained by the effects of negative group delay and the less likely 
>explanation of propagation faster than c?   Why do you think the less 
>likely explanation is the correct one?   How do you plan to prove that 
>the less likely explanation should be accepted?
>
>
>> Regarding your request that I interrupt the input signal, isn't this
what I
>> did in the LPF Pulse simulation I just posted? The pulse is turned on
and
>> off and both edges arrive ealier than if it propagted at the speed of
>> light. I guess I could do it without the LPF, but the signal would be
>> wideband and distort in the nearfield.
>
>Are you trying to say the nearfield distortion of the wideband component 
>would suggest that the propagation is less than or equal to c?   That's 
>pretty much the point.
>
>The expectation is that you'll see something similar to Figure 7 in 
>Andor's blog article.  You're seeing essentially Figure 5 now, or Fig. 
>2a. in Sten's paper.
>
>
>> But the discontinuity in this signal
>> would appear to propagate at the speed of light, because the high
frequency
>> components comprising the discontinuity would propagate at light speed,
>> since they are in the farfield.
>
>Yup.  Which suggests that the signal isn't really propagating faster 
>than c after all, it's just dispersing in a way that advances the phase 
>and makes it appear to accelerate, like the citations we've been quoting 
>over and over and over.
>
>> Remember that the speed of the field is
>> only superluminal in the nearfield and reduces to the speed of light (c)
as
>> the field propagates about a wavelegth from the dipole source, and
>> continues to propagate at c into the farfield.
>
>I think most disagree with you here, and think that the pulse just 
>distorts in the near field due to the dispersion and advances the phase, 
>just like it does in Andor's negative group delay filter and Sten's 
>paper.  You're the only one I know of claiming the explanation is 
>propagation faster than c.   Everybody else seems to think it's just the 
>phase advance due to the dispersion.  Your results appear consistent 
>with Andor's and Sten's so far as far as I can tell, but you insist on a 
>different explanation.
>
>Eric
>
>
>> If the detector is located
>> at 1/6 carrier wavelength from the dipole, then higher frequency
components
>> with wavelengths a lot shorter than this distance will propagate at
speed
>> c.
>>
>>
>> William
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 27 Mar, 02:35, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> Are the insults really necessary!

There ar eno insults. Merely statements of facts. The facts are
that you hva esaid nothing in this thread that can not be explained
by your total lack of knowledge or understanding of even the
simplest, most fundamental basics.

> This is a serious discussion and the
> concepts are not easy.

This is an amateur who is dabbling with trivialities.

> It is a complex system.

In your would it might be - most people who have passed EM 101
think otherwise.

> I garentee no one knows
> exactly what is going on in this system. Insults and ridicule are simply
> childish and unbecomming in an intelectual discussion.

As I said, most people who actually know the basics will
think this is about total lack of basic knowledge.

> Regarding your two monopole model, this is a mathematical approximation.

No, it is not. The monopole is the essential building block
in elementary linear wave theory. Unless you start messing
with nonlinear interactions (i.e. the imposed EM field alters
the properties of the mediom, like in e.g. plasma) there is
no need to extend beyond the superposition of monopoles.

Of course, if you knew the basick of monoples (I suspect you
don't) you would know that the uniformely radiating monopole
is derived as a uniformely oscillating spfere of radius, say, a.
If you knew the basics of monopoles (I suspect you don't) you
would know that the solution of the corresponding wave equation
involves spherical Bessel functions. If you knew the basics
of monopoles (I suspect you don't) you would know that the
monopole's radiating field when the wavelength is a lot larger
than the diameter a, is modeled with a point source. If you knew
the basics of monopoles (I suspect you don't) you would know
that the Bessel functions have max amplitude 1 at argument 0.
If you knew the basics of monopoles (I suspect you don't)
you would know that the exponential *asymptotic* forms are
valid only for very large arguments.

In short, if you had even the slightest clue of any of this,
you would know that the starting point of the analysis,
equation 43 in your paper

http://xxx.lanl.gov/ftp/physics/papers/0603/0603240.pdf

is the place where you go wrong. You keep the asymptotic form
exp(kr)/r of the Bessel J, and ignore the higher order terms.
Those higher order terms might be nuisance factors in the far
field, but arre increasingly important the closer in towards
the monopole you get.

Again, totally trivial material.

I'll bet you a pint of beer that if you

1) Derive the correct equations fro the monopole
2) Regard the dipole as a superpositions of monoples
3) Run the simulation using the correct equations
   (i.e. use the Bessel functions, not the asymptotic
   forms) for the field,

the interference effect will first of all be obvious;
second the "faster-than-light" BS will almost certainly
go away.

As I said (and these are merely statements of facts):
The remarkable intellectual feat here, with the number
of aspects, factors and questions involved, that you
have managed to get every single one of them wrong.

To what extent peple here are intrigued, it is not by
the questions you ask, but that you have proved unable
to get a single argument right.

Rune

Rune,

If you are going to be rude, don't bother posting. I will not answer your
posts if you continue. I am sure you have interesting things to say and I
am interested in discussing it, but not if your going to be rude.

William


>On 27 Mar, 02:35, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Rune,
>>
>> Are the insults really necessary!
>
>There ar eno insults. Merely statements of facts. The facts are
>that you hva esaid nothing in this thread that can not be explained
>by your total lack of knowledge or understanding of even the
>simplest, most fundamental basics.
>
>> This is a serious discussion and the
>> concepts are not easy.
>
>This is an amateur who is dabbling with trivialities.
>
>> It is a complex system.
>
>In your would it might be - most people who have passed EM 101
>think otherwise.
>
>> I garentee no one knows
>> exactly what is going on in this system. Insults and ridicule are
simply
>> childish and unbecomming in an intelectual discussion.
>
>As I said, most people who actually know the basics will
>think this is about total lack of basic knowledge.
>
>> Regarding your two monopole model, this is a mathematical
approximation.
>
>No, it is not. The monopole is the essential building block
>in elementary linear wave theory. Unless you start messing
>with nonlinear interactions (i.e. the imposed EM field alters
>the properties of the mediom, like in e.g. plasma) there is
>no need to extend beyond the superposition of monopoles.
>
>Of course, if you knew the basick of monoples (I suspect you
>don't) you would know that the uniformely radiating monopole
>is derived as a uniformely oscillating spfere of radius, say, a.
>If you knew the basics of monopoles (I suspect you don't) you
>would know that the solution of the corresponding wave equation
>involves spherical Bessel functions. If you knew the basics
>of monopoles (I suspect you don't) you would know that the
>monopole's radiating field when the wavelength is a lot larger
>than the diameter a, is modeled with a point source. If you knew
>the basics of monopoles (I suspect you don't) you would know
>that the Bessel functions have max amplitude 1 at argument 0.
>If you knew the basics of monopoles (I suspect you don't)
>you would know that the exponential *asymptotic* forms are
>valid only for very large arguments.
>
>In short, if you had even the slightest clue of any of this,
>you would know that the starting point of the analysis,
>equation 43 in your paper
>
>http://xxx.lanl.gov/ftp/physics/papers/0603/0603240.pdf
>
>is the place where you go wrong. You keep the asymptotic form
>exp(kr)/r of the Bessel J, and ignore the higher order terms.
>Those higher order terms might be nuisance factors in the far
>field, but arre increasingly important the closer in towards
>the monopole you get.
>
>Again, totally trivial material.
>
>I'll bet you a pint of beer that if you
>
>1) Derive the correct equations fro the monopole
>2) Regard the dipole as a superpositions of monoples
>3) Run the simulation using the correct equations
>   (i.e. use the Bessel functions, not the asymptotic
>   forms) for the field,
>
>the interference effect will first of all be obvious;
>second the "faster-than-light" BS will almost certainly
>go away.
>
>As I said (and these are merely statements of facts):
>The remarkable intellectual feat here, with the number
>of aspects, factors and questions involved, that you
>have managed to get every single one of them wrong.
>
>To what extent peple here are intrigued, it is not by
>the questions you ask, but that you have proved unable
>to get a single argument right.
>
>Rune
>

On 28 Mar, 16:12, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> If you are going to be rude, don't bother posting. I will not answer your
> posts if you continue. I am sure you have interesting things to say and I
> am interested in discussing it, but not if your going to be rude.

You have been met here with far more respect than you deserve.
In fact, your inflated ego is the only issue standing beteen
you and some real insights. You *think* what you dabble with
is difficult. It is not. It's nothing more than the basics
most other people did away with during their first semester
of wave theory.

You have spent a decade and a half messing with the basics.
*Read* my posts. *Contemplate* what I say. *Search* *up* *the*
*basics* on the trivial stuff you dabble with.

Then find a new vocation.

Rune

On 3/28/2010 4:24 AM, WWalker wrote:
> Eric,
>
> I think you are missing the point. Refering to the Low Pass Filtered Pulse
> simulation I posted, the simulation clearly shows that if I transmit a
> pulse, the pulse edge arrives sooner than if it had propagated faster than
> light. If my detector at the receiving end is threshold detector which is
> set to look for anything above the noise level, it will fire earlier than
> if the pulse had propagated at light speed. In other words, it shows that
> if I push a button launching the narrowband pulse signal and propagate it
> via a dipole to a nearfield receiver with the threshold detector, the
> pressed button will be detected sooner than a light propagated signal. This
> clearly shows that an action (informaton) in this nearfield dipole system
> can be detected faster than light. If this is true than I have proven my
> point that information propagtes faster than light in the nearfield of a
> dipole.
>
> William

I get the impression that you either haven't read or haven't understood 
any of our previous dialogue.

What you are seeing appears consistent with a phase advance of a 
bandlimited signal, not accelerated propagation.   The same sort of 
bandlimited pulse is shown, and I'm sure everybody is getting weary of 
me citing these same references over and over again, with apparent 
acceleration in Andor's blog (Figures 4 and 5) and in Sten's paper (Fig. 
2.a).

Both show apparent arrival of the output pulse before the input, but it 
is only a small phase advance of the signal due to the nature of the 
medium (i.e., an unusual group delay).  Both authors acknowledge this. 
  You do not.   Andor demonstrated, pretty clearly, that the system is, 
in fact, causal, by turning off the input signal and observing the 
output signal end in Fig. 7.   This is why people here have been trying 
to get you to do something similar, because otherwise the logical 
explanation is that there's just a slight phase advance in the signal.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric, 

I am sorry to insist, but it does not matter what the reason is. If I have
a communication link that allows me to transmit a pulse over a distance
faster than a light propagated pulse, then the pulse propagates faster than
light. If I use the pulse to denonate a bomb located a distance away, the
bomb will explode sooner than if the pulse propagated at the speed of
light. This is absolutly true and cannot be argued. The only question is if
the dipole simulation demonstrates that a pulse can be detected over a
distance faster than light. I think it has.

The Andor circuit is only phase shifting the signal so that it appears the
signal outputs before it is sent. The proof is that you can not use the
circuit to turn itself off before the message was sent, thereby preventing
the message from being sent in the first place. This is clearly shown in
Fig. 7. Also note that in my dipole system the pulse always arrives after
it is sent, not before as in Andor's circuit. 

Figure 2 in the Sten paper is showing the propagation of a pulse in the
nearfield using the transverse electric field, where I and talking about
the magnetic field component and my signals always arrive at the detector
after they are sent, not before. Note the transverse electric field pulse
in Fig 2b arrives before the signal was sent. This is because the
transverse field is being created 1/4 wavelength outside the source and
propagates both back toward the dipole and away from the source. At
distances larger than the 1/4 wavelength the pulse is seen to propagate
away from the dipole. If you plot Stens group speed Eq. 18 you can clearly
see this. Refer my paper Eq. 72, and plot Fig.14. An animation showing this
is shown in Fig. 20, 21, 23
 

William


>On 3/28/2010 4:24 AM, WWalker wrote:
>> Eric,
>>
>> I think you are missing the point. Refering to the Low Pass Filtered
Pulse
>> simulation I posted, the simulation clearly shows that if I transmit a
>> pulse, the pulse edge arrives sooner than if it had propagated faster
than
>> light. If my detector at the receiving end is threshold detector which
is
>> set to look for anything above the noise level, it will fire earlier
than
>> if the pulse had propagated at light speed. In other words, it shows
that
>> if I push a button launching the narrowband pulse signal and propagate
it
>> via a dipole to a nearfield receiver with the threshold detector, the
>> pressed button will be detected sooner than a light propagated signal.
This
>> clearly shows that an action (informaton) in this nearfield dipole
system
>> can be detected faster than light. If this is true than I have proven
my
>> point that information propagtes faster than light in the nearfield of
a
>> dipole.
>>
>> William
>
>I get the impression that you either haven't read or haven't understood 
>any of our previous dialogue.
>
>What you are seeing appears consistent with a phase advance of a 
>bandlimited signal, not accelerated propagation.   The same sort of 
>bandlimited pulse is shown, and I'm sure everybody is getting weary of 
>me citing these same references over and over again, with apparent 
>acceleration in Andor's blog (Figures 4 and 5) and in Sten's paper (Fig. 
>2.a).
>
>Both show apparent arrival of the output pulse before the input, but it 
>is only a small phase advance of the signal due to the nature of the 
>medium (i.e., an unusual group delay).  Both authors acknowledge this. 
>  You do not.   Andor demonstrated, pretty clearly, that the system is, 
>in fact, causal, by turning off the input signal and observing the 
>output signal end in Fig. 7.   This is why people here have been trying 
>to get you to do something similar, because otherwise the logical 
>explanation is that there's just a slight phase advance in the signal.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 3/28/2010 11:40 AM, WWalker wrote:
> Eric,
>
> I am sorry to insist, but it does not matter what the reason is.  If I have
> a communication link that allows me to transmit a pulse over a distance
> faster than a light propagated pulse, then the pulse propagates faster than
> light.

I suppose you can argue semantics here about what defines the "pulse", 
but understand that "information" is not propagating faster than light 
in any of the examples, and neither is energy.  This seems to be the key 
point that must be understood.   A simple small phase advance of a 
signal is NOT indicative of information exceeding the speed of light.

If you just want to claim that the signal has phase advanced and appears 
to arrive earlier than expected, that's fine, I don't think anyone will 
argue with you there.  That's what has led to discussion and study on 
this topic in many places.

> If I use the pulse to denonate a bomb located a distance away, the
> bomb will explode sooner than if the pulse propagated at the speed of
> light. This is absolutly true and cannot be argued. The only question is if
> the dipole simulation demonstrates that a pulse can be detected over a
> distance faster than light. I think it has.

If you want to wave your hands about the definition of the pulse, sure. 
   If you want to claim that actual information has been accelerated, 
then, no.  You've demonstrated something that's been known for a long 
time, that bandlimited signals have a predictable quality than can be 
exploited.  That's not new.

> The Andor circuit is only phase shifting the signal so that it appears the
> signal outputs before it is sent. The proof is that you can not use the
> circuit to turn itself off before the message was sent, thereby preventing
> the message from being sent in the first place. This is clearly shown in
> Fig. 7. Also note that in my dipole system the pulse always arrives after
> it is sent, not before as in Andor's circuit.

The relevant part of the argument is that the signal arrives before 
expected.   Whether the acceleration is due to negative group delay or 
phase velocity or some other mathematical arrangement, the point is that 
a bandlimited signal can appear to be predicted by fairly simple 
processes.  The circuit in Andor's example isn't very complicated.  The 
mechanisms by which the dispersion or phase response is affected in the 
near field of an antenna doesn't appear to be out of that realm at all. 
  The key point is that there is a straightforward explanation that 
doesn't involve non-causality or propagation faster than light.

So when somebody comes along and shows the exact same sort of small 
phase advance associated with bandlimited prediction and says, "this 
proves propagation faster than c!", it cannot be taken as true by anyone 
who knows of the more likely explanation.   There is a very large burden 
of proof that goes with such a claim, and I haven't seen anything that 
would indicate to me a single step past the ordinary explanation.


> Figure 2 in the Sten paper is showing the propagation of a pulse in the
> nearfield using the transverse electric field, where I and talking about
> the magnetic field component and my signals always arrive at the detector
> after they are sent, not before. Note the transverse electric field pulse
> in Fig 2b arrives before the signal was sent. This is because the
> transverse field is being created 1/4 wavelength outside the source and
> propagates both back toward the dipole and away from the source. At
> distances larger than the 1/4 wavelength the pulse is seen to propagate
> away from the dipole. If you plot Stens group speed Eq. 18 you can clearly
> see this. Refer my paper Eq. 72, and plot Fig.14. An animation showing this
> is shown in Fig. 20, 21, 23

Perhaps what you think you're demonstrating is the mechanism by which 
the system achieves the same sort of bandlimited prediction experienced 
in a negative group delay filter.   Again, that's far, far more 
believable than propagation faster than c, especially when it's a known 
and understood phenomenon.

Yet again let me point out that a discontinuity like that shown in 
Andor's analysis might be able to be measured through your system.  It's 
clear you're not trying to show causality, but propagation.   So why not 
demonstrate the discontinuity propagating faster than c?  I'd think it'd 
be a good experiment and might reveal something useful about the system.

I think until you can demonstrate something like that the more likely 
explanation of bandlimited prediction would be expected to prevail.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

WWalker <william.walker@n_o_s_p_a_m.imtek.de> wrote:
 
> I am sorry to insist, but it does not matter what the reason is. If I have
> a communication link that allows me to transmit a pulse over a distance
> faster than a light propagated pulse, then the pulse propagates faster than
> light. If I use the pulse to denonate a bomb located a distance away, the
> bomb will explode sooner than if the pulse propagated at the speed of
> light. This is absolutly true and cannot be argued. The only question is if
> the dipole simulation demonstrates that a pulse can be detected over a
> distance faster than light. I think it has.

No it doesn't.  

A narrow band pulse has to build up slowly.  If it has a sudden
edge then it necessarily has a wide bandwidth.  A common case
is a wave packet with a Gaussian envelope.  With such a pulse,
there is some signal long before the main part of the pulse, and
that can be detected.  There are materials that can amplify the
leading edge of a pulse, and attenuate the rest.  The result is
a new pulse that seems to have gone faster than c.  If you try
to use it for information transmission, though, you will find
that it does not violate special relativity.

-- glen

Eric Jacobsen wrote:

   ...

> I think until you can demonstrate something like that the more likely 
> explanation of bandlimited prediction would be expected to prevail.

Even allowing the unlikely possibility that the 6-degree phase advance 
*in the near field* represents a real speed increase, and that the 
"pulse" in the far field is expected to show no advance at all, What 
practical use can this have?

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

>On 3/28/2010 11:40 AM, WWalker wrote:
>> Eric,
>>
>> I am sorry to insist, but it does not matter what the reason is.  If I
have
>> a communication link that allows me to transmit a pulse over a distance
>> faster than a light propagated pulse, then the pulse propagates faster
than
>> light.
>
>I suppose you can argue semantics here about what defines the "pulse", 
>but understand that "information" is not propagating faster than light 
>in any of the examples, and neither is energy.  This seems to be the key 
>point that must be understood.   A simple small phase advance of a 
>signal is NOT indicative of information exceeding the speed of light.
>
>If you just want to claim that the signal has phase advanced and appears 
>to arrive earlier than expected, that's fine, I don't think anyone will 
>argue with you there.  That's what has led to discussion and study on 
>this topic in many places.

Now you're getting to the crux. Information is energy. Real physical
energy. Not virtual photons, and other smoke and mirrors. Its real physical
energy of the kind that gets water hot. Show energy flow faster than light
and you've shown information flow faster than light. Fail, and you
haven't.

>> If I use the pulse to denonate a bomb located a distance away, the
>> bomb will explode sooner than if the pulse propagated at the speed of
>> light. This is absolutly true and cannot be argued. The only question is
if
>> the dipole simulation demonstrates that a pulse can be detected over a
>> distance faster than light. I think it has.

Bombs dissipate real physical energy. This is why nobody disputes the
carriage of information - typically the news that someone is seriously
pissed off. Until the energy starts to dissipate, the information has not
arrived (although side channel information, like seeing the bomb fly over,
may well arrive earlier). Demonstrate an energy flow faster than light, and
we'll all be amazed, and you'll be rich.

Steve

On 28 Mar, 22:13, Eric Jacobsen <eric.jacob...@ieee.org> wrote:

> Perhaps what you think you're demonstrating is the mechanism by which
> the system achieves the same sort of bandlimited prediction experienced
> in a negative group delay filter.

The guy has done nothing of the sort. What he has done, is to
fail Wave Theory 101 and use the *approximate* expression valid
in the (distant) far field in the immediate vicinity of the
monopoles. A freshman blunder.

If this amateur WW goes back to Wave Theory 101 and

1) Actually derives the expressions for the radiating monopole
   (which include Hankel functions)
2) Applies the trivial superporsition principle with the two
   monopoles in question
3) Runs the *correct* simulation and not the far field
   approximation
4) Accounts for trivial interference effects

there will be no more dicussions. Somebody suggested that
WW is not stupid. Let him (WW) support such a claim by showing
that he is able to do the trivial exercise indicated above.

Rune

Rune,

The transfer function I use in my simulations is well known for the
magnetic field component of an electric dipole: (1/r^2)e^(ikr)[ikr-1]. You
can look this up in any EM book or look at my paper Eq. 46 were I have
derived it from Maxwell Equations, also refer to Eqn 9 in the Sten paper.
It is well known and stated clearly in most text books that the model is
only valid provided the distance to the observation point is much larger
than the dipole length. Since a dipole can be arbitrarily small, this
limitation of the model can be satisfied in the nearfield of a dipole. So
in summation, the model I use in my simulations is valid in the nearfield,
provided the dipole length is much smaller than the distance to the
observation point.

William


>On 28 Mar, 22:13, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
>
>> Perhaps what you think you're demonstrating is the mechanism by which
>> the system achieves the same sort of bandlimited prediction experienced
>> in a negative group delay filter.
>
>The guy has done nothing of the sort. What he has done, is to
>fail Wave Theory 101 and use the *approximate* expression valid
>in the (distant) far field in the immediate vicinity of the
>monopoles. A freshman blunder.
>
>If this amateur WW goes back to Wave Theory 101 and
>
>1) Actually derives the expressions for the radiating monopole
>   (which include Hankel functions)
>2) Applies the trivial superporsition principle with the two
>   monopoles in question
>3) Runs the *correct* simulation and not the far field
>   approximation
>4) Accounts for trivial interference effects
>
>there will be no more dicussions. Somebody suggested that
>WW is not stupid. Let him (WW) support such a claim by showing
>that he is able to do the trivial exercise indicated above.
>
>Rune
>

Eric,

Could you elaboate on your comment below. I think we need to agree on the
definition of information in regards to the LPF pulsed carrier simulation.
How does your comment refute my argument presented again below?

>I suppose you can argue semantics here about what defines the "pulse",

Again I claim:

"Refering to the Low Pass Filtered Pulse
simulation I posted, the simulation clearly shows that if I transmit a
pulse, the pulse edge arrives sooner than if it had propagated faster than
light. If my detector at the receiving end is a threshold detector which
is
set to look for anything above the noise level, it will fire earlier than
if the pulse had propagated at light speed. In other words, it shows that
if I push a button launching the narrowband pulse signal and propagate it 
via a dipole to a nearfield receiver with the threshold detector, the
pressed button will be detected sooner than a light propagated signal.
This
clearly shows that an action (informaton) in this nearfield dipole system
can be detected faster than light. If this is true than I have proven my
point that information propagtes faster than light in the nearfield of a
dipole."

"it does not matter what the reason is. If I have
a communication link that allows me to transmit a pulse over a distance
faster than a light propagated pulse, then the pulse propagates faster
than
light. If I use the pulse to denonate a bomb located a distance away, the
bomb will explode sooner than if the pulse propagated at the speed of
light. This is absolutly true and cannot be argued. The only question is
if
the dipole simulation demonstrates that a pulse can be detected over a
distance faster than light. I think it has.
"

So if press a button with the same signal characteristics as the LPF pulse,
and if I use the above setup to detect the pulse and explode a bomb, the
bomb will explode earlier than if the pulse propagated at the speed of
light. The pressing of the button (Action) results in the exploding of a
bomb (Reaction) faster than light speed. This is clear cause and effect
(information) which propagtes faster than light.  


William



>I suppose you can argue semantics here about what defines the "pulse",

>On 3/28/2010 11:40 AM, WWalker wrote:
>> Eric,
>>
>> I am sorry to insist, but it does not matter what the reason is.  If I
have
>> a communication link that allows me to transmit a pulse over a distance
>> faster than a light propagated pulse, then the pulse propagates faster
than
>> light.
>
>I suppose you can argue semantics here about what defines the "pulse", 
>but understand that "information" is not propagating faster than light 
>in any of the examples, and neither is energy.  This seems to be the key 
>point that must be understood.   A simple small phase advance of a 
>signal is NOT indicative of information exceeding the speed of light.
>
>If you just want to claim that the signal has phase advanced and appears 
>to arrive earlier than expected, that's fine, I don't think anyone will 
>argue with you there.  That's what has led to discussion and study on 
>this topic in many places.
>
>> If I use the pulse to denonate a bomb located a distance away, the
>> bomb will explode sooner than if the pulse propagated at the speed of
>> light. This is absolutly true and cannot be argued. The only question is
if
>> the dipole simulation demonstrates that a pulse can be detected over a
>> distance faster than light. I think it has.
>
>If you want to wave your hands about the definition of the pulse, sure. 
>   If you want to claim that actual information has been accelerated, 
>then, no.  You've demonstrated something that's been known for a long 
>time, that bandlimited signals have a predictable quality than can be 
>exploited.  That's not new.
>
>> The Andor circuit is only phase shifting the signal so that it appears
the
>> signal outputs before it is sent. The proof is that you can not use the
>> circuit to turn itself off before the message was sent, thereby
preventing
>> the message from being sent in the first place. This is clearly shown
in
>> Fig. 7. Also note that in my dipole system the pulse always arrives
after
>> it is sent, not before as in Andor's circuit.
>
>The relevant part of the argument is that the signal arrives before 
>expected.   Whether the acceleration is due to negative group delay or 
>phase velocity or some other mathematical arrangement, the point is that 
>a bandlimited signal can appear to be predicted by fairly simple 
>processes.  The circuit in Andor's example isn't very complicated.  The 
>mechanisms by which the dispersion or phase response is affected in the 
>near field of an antenna doesn't appear to be out of that realm at all. 
>  The key point is that there is a straightforward explanation that 
>doesn't involve non-causality or propagation faster than light.
>
>So when somebody comes along and shows the exact same sort of small 
>phase advance associated with bandlimited prediction and says, "this 
>proves propagation faster than c!", it cannot be taken as true by anyone 
>who knows of the more likely explanation.   There is a very large burden 
>of proof that goes with such a claim, and I haven't seen anything that 
>would indicate to me a single step past the ordinary explanation.
>
>
>> Figure 2 in the Sten paper is showing the propagation of a pulse in the
>> nearfield using the transverse electric field, where I and talking
about
>> the magnetic field component and my signals always arrive at the
detector
>> after they are sent, not before. Note the transverse electric field
pulse
>> in Fig 2b arrives before the signal was sent. This is because the
>> transverse field is being created 1/4 wavelength outside the source and
>> propagates both back toward the dipole and away from the source. At
>> distances larger than the 1/4 wavelength the pulse is seen to propagate
>> away from the dipole. If you plot Stens group speed Eq. 18 you can
clearly
>> see this. Refer my paper Eq. 72, and plot Fig.14. An animation showing
this
>> is shown in Fig. 20, 21, 23
>
>Perhaps what you think you're demonstrating is the mechanism by which 
>the system achieves the same sort of bandlimited prediction experienced 
>in a negative group delay filter.   Again, that's far, far more 
>believable than propagation faster than c, especially when it's a known 
>and understood phenomenon.
>
>Yet again let me point out that a discontinuity like that shown in 
>Andor's analysis might be able to be measured through your system.  It's 
>clear you're not trying to show causality, but propagation.   So why not 
>demonstrate the discontinuity propagating faster than c?  I'd think it'd 
>be a good experiment and might reveal something useful about the system.
>
>I think until you can demonstrate something like that the more likely 
>explanation of bandlimited prediction would be expected to prevail.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Steve,

Clearly energy is also propagating faster than light in the dipole system.
If the pulsed carrier is propagating faster than light, as shown in my
simulaton, then the energy of this signal is just the signal squared and
low pass filtered. This is exactly how I detected the signal in my
simulation. So the detected pulse I showed in my simulation is also
proportional to the energy.   

William  


>>On 3/28/2010 11:40 AM, WWalker wrote:
>>> Eric,
>>>
>>> I am sorry to insist, but it does not matter what the reason is.  If I
>have
>>> a communication link that allows me to transmit a pulse over a
distance
>>> faster than a light propagated pulse, then the pulse propagates faster
>than
>>> light.
>>
>>I suppose you can argue semantics here about what defines the "pulse", 
>>but understand that "information" is not propagating faster than light 
>>in any of the examples, and neither is energy.  This seems to be the key

>>point that must be understood.   A simple small phase advance of a 
>>signal is NOT indicative of information exceeding the speed of light.
>>
>>If you just want to claim that the signal has phase advanced and appears

>>to arrive earlier than expected, that's fine, I don't think anyone will 
>>argue with you there.  That's what has led to discussion and study on 
>>this topic in many places.
>
>Now you're getting to the crux. Information is energy. Real physical
>energy. Not virtual photons, and other smoke and mirrors. Its real
physical
>energy of the kind that gets water hot. Show energy flow faster than
light
>and you've shown information flow faster than light. Fail, and you
>haven't.
>
>>> If I use the pulse to denonate a bomb located a distance away, the
>>> bomb will explode sooner than if the pulse propagated at the speed of
>>> light. This is absolutly true and cannot be argued. The only question
is
>if
>>> the dipole simulation demonstrates that a pulse can be detected over a
>>> distance faster than light. I think it has.
>
>Bombs dissipate real physical energy. This is why nobody disputes the
>carriage of information - typically the news that someone is seriously
>pissed off. Until the energy starts to dissipate, the information has not
>arrived (although side channel information, like seeing the bomb fly
over,
>may well arrive earlier). Demonstrate an energy flow faster than light,
and
>we'll all be amazed, and you'll be rich.
>
>Steve
>
>

On 29 Mar, 17:06, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> The transfer function I use in my simulations is well known for the
> magnetic field component of an electric dipole: (1/r^2)e^(ikr)[ikr-1]. You
> can look this up in any EM book or look at my paper Eq. 46 were I have
> derived it from Maxwell Equations,

Neither the textbooks nor you have derived anything.
You (and the textbooks) refer to tabulated approimation
you don't understand how were derived, or the extent
of their validity.

The key to pinning down the causes of your incompetence
is to derive the results from scratch. I have already
told you how to do this in a different post.

> It is well known and stated clearly in most text books that the model is
> only valid provided the distance to the observation point is much larger
> than the dipole length.

Again: Your problem is that you don't understand the basics.
Start with the monople. The results you have "derived" are
only valid in the far field of the monoploe (which, of course,
you would have known had you *read* my previous posts). Once
you understand it fully, you might advance to the dipole.

As I said before: Your ego is your problem. There is no point
refering or listiong results if you don't contemplate their
impact and consequences. You have demonstrated a unique
ability *not* to think.

You will not get anywhere unless you acknowledge that fact.

Rune

Jerry,

The speed of light is a corner stone in physics and if it is not a constant
then many of our theories in physics will be affected. There may be direct
practical uses as well, but I just guessing: improving accuracy of high
speed doppler radar, speeding up communication to spacecraft where time
delays are problematic, increasing speed of computers when they are
eventually limited by light speed delays etc. As I said, these are only
guesses, the main effect would be a change in many of our theories in
physics, which would eventually lead to new practical uses and
technologies.

William 




>Eric Jacobsen wrote:
>
>   ...
>
>> I think until you can demonstrate something like that the more likely 
>> explanation of bandlimited prediction would be expected to prevail.
>
>Even allowing the unlikely possibility that the 6-degree phase advance 
>*in the near field* represents a real speed increase, and that the 
>"pulse" in the far field is expected to show no advance at all, What 
>practical use can this have?
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

On Mar 28, 4:13=A0pm, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
> On 3/28/2010 11:40 AM, WWalker wrote:
>
> > I am sorry to insist, but it does not matter what the reason is. =A0If =
I have
> > a communication link that allows me to transmit a pulse over a distance
> > faster than a light propagated pulse, then the pulse propagates faster =
than
> > light.
>
> I suppose you can argue semantics here about what defines the "pulse",
> but understand that "information" is not propagating faster than light
> in any of the examples, and neither is energy. =A0This seems to be the ke=
y
> point that must be understood. =A0 A simple small phase advance of a
> signal is NOT indicative of information exceeding the speed of light.
>
> If you just want to claim that the signal has phase advanced and appears
> to arrive earlier than expected, that's fine, I don't think anyone will
> argue with you there. =A0That's what has led to discussion and study on
> this topic in many places.
>
> > If I use the pulse to denonate a bomb located a distance away, the
> > bomb will explode sooner than if the pulse propagated at the speed of
> > light. This is absolutely true and cannot be argued.

well, it *is* argued.

this is funny, because i have been in similar discussions but on
sci.physics.research or sci.physics.foundations or, in the past, the
Physics Forums site.  i haven't seen it here on comp.dsp.  sometimes
the discussion is about the speed of gravity (in comparison to the
speed of electromagnetic propagation a.k.a. "speed of light").  now, i
*do* seem to remember reading something about the group velocity of
some modulated light source exceeding the phase velocity in some
medium.  i don't usually concern myself with non-vacuum propagation
since, at the atomic level, it's a vacuum between the atoms and when
epsilon differs from epsilon_0 it's a macroscopic *aggregate* effect
of the polarization of molecules in the medium.  same with mu and
mu_0.

the speed of light (or of EM) in a vacuum, what we call "c", is not a
property of E&M, but is a property of space and time.  it doesn't
matter what the "instantaneous" force or interaction is.  could be EM,
gravity, strong (turns out weak is mediated by particles with mass, so
it ain't as instantaneous).

suppose you are standing there and i am standing here, some distance
away.  now suppose you are holding a big negative charge and i am
holding a big positive charge and we are both restricting the movement
of our charges to a plane that is perpendicular to the line connecting
the two of us.  since our charges are attracted to each other, when i
move my charge up, your charge follows it up.  if i move it down, your
charge follows it down.  if i move it to my right, your charge follows
it to your left (assuming we are facing each other).  similarly if i
move my charge to my left, your charge follows to your right.  if i
move my charge up and down repeatedly, yours will follow it up and
down repeatedly.  i am literally a "transmitting antenna" and you are
a "receiving antenna".  if i move my charge up and down a million
times per second, you could tune it in with an AM radio.  if i move it
left and right 100 million times per second, you can tune it in with
an FM radio.  if i move it back and forth 500 trillion times per
second, you would see it as a blur of orange color.  that's what EM
radiation is, at a fundamental level.

now imagine there is a third party observing us at a distance and is
equidistant from us both.  and suppose this third party knows, from
some other means, what the distance is between us. no matter what i do
with the charge, when the observer sees the perturbation of position
on my end and then observes a perturbation at your end, the time
differential between the cause and effect will always be that distance
between us divided by c.  i don't care what you read or what you think
W, that's what it is.

it would be the same if you and i were the size of gods and, instead
of charges, i was holding a planet and you were holding a planet.  i
perturb the position of my planet and your planet will get disturbed
by that change of gravitational field and the time differential
between the disturber and disturbed will be the distance between the
two of us divided by the *same* c.  so, even if we tried to use
gravity waves to communicate information, we would still be limited by
the speed c.

now, despite what we sometimes read, it isn't that Nature is imposing
a fundamental limit to the speed of propagation of information, it's
that Nature, namely the fundamental nature of space and time, imposes
a finite limit of speed of the fundamental interactions, of which all
of physical reality is built upon.  *that* is what imposes a limit of
speed of conveyance of information since information is conveyed by a
physical interaction.

there is nothing magical about that speed "c".  all the physics needs
is that c is real, positive, and finite.  it could be *any* speed (as
observed by a god-like observer who is not himself affected by the
physics).  for those of us who are mortal and are governed by the
interactions of Nature, all of the rest of reality would be scaled in
such a way that the speed of propagation, c, would appear to be the
same, *unless* some *dimensionless* fundamental physical constant
(like alpha) changes.  and then, the salient fact is that this
dimensionless "constant" changed (not c).  we don't measure or
perceive dimensionful quantities directly, but we *always* measure or
perceive such as a ratio against a reference quantity of the same
dimension.  there is always a reference voltage in our DVM, there are
always pre-existing tick marks on our ruler.  the dimensionful
quantity we call "c" is more of an expression of the anthropometric
units we happen to be using to measure length and time.

WWalker, i might suggest that you take this up at
sci.physic.foundations or maybe sci.physics.research (both are
moderated) or go to the PhysicsForums.com site.

r b-j

WWalker wrote:
> Jerry,
> 
> The speed of light is a corner stone in physics and if it is not a constant
> then many of our theories in physics will be affected. There may be direct
> practical uses as well, but I just guessing: improving accuracy of high
> speed doppler radar, speeding up communication to spacecraft where time
> delays are problematic, increasing speed of computers when they are
> eventually limited by light speed delays etc. As I said, these are only
> guesses, the main effect would be a change in many of our theories in
> physics, which would eventually lead to new practical uses and
> technologies.
> 
> William 

How much Doppler radar is done within half a wavelength of the antenna? 
One might as well use a tape measure for distance, and if the Doppler 
shift amounts to anything, duck!


Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi

WWalker wrote:
> Steve,
> 
> Clearly energy is also propagating faster than light in the dipole system.
> If the pulsed carrier is propagating faster than light, as shown in my
> simulaton, then the energy of this signal is just the signal squared and
> low pass filtered. This is exactly how I detected the signal in my
> simulation. So the detected pulse I showed in my simulation is also
> proportional to the energy.   

I once did a titration simulation for a chemistry class. In most 
respects, it was as real as I could make it.  As neutrality was 
approached, each drop of reagent flashed before it expanded and faded. 
The time to fading was a good clue to the pH. To remind the students 
that a simulation may be made to show whatever the author wants it to, 
the simulation differed in one very obvious way: the phenolphthalein 
turned green, not red.

How do you know that you aren't looking at green phenolphthalein?

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On 3/29/2010 8:42 AM, WWalker wrote:
> Eric,
>
> Could you elaboate on your comment below. I think we need to agree on the
> definition of information in regards to the LPF pulsed carrier simulation.
> How does your comment refute my argument presented again below?
>
>> I suppose you can argue semantics here about what defines the "pulse",
>
> Again I claim:
>
> "Refering to the Low Pass Filtered Pulse
> simulation I posted, the simulation clearly shows that if I transmit a
> pulse, the pulse edge arrives sooner than if it had propagated faster than
> light. If my detector at the receiving end is a threshold detector which
> is
> set to look for anything above the noise level, it will fire earlier than
> if the pulse had propagated at light speed. In other words, it shows that
> if I push a button launching the narrowband pulse signal and propagate it
> via a dipole to a nearfield receiver with the threshold detector, the
> pressed button will be detected sooner than a light propagated signal.
> This
> clearly shows that an action (informaton) in this nearfield dipole system
> can be detected faster than light. If this is true than I have proven my
> point that information propagtes faster than light in the nearfield of a
> dipole."
>
> "it does not matter what the reason is. If I have
> a communication link that allows me to transmit a pulse over a distance
> faster than a light propagated pulse, then the pulse propagates faster
> than
> light. If I use the pulse to denonate a bomb located a distance away, the
> bomb will explode sooner than if the pulse propagated at the speed of
> light. This is absolutly true and cannot be argued. The only question is
> if
> the dipole simulation demonstrates that a pulse can be detected over a
> distance faster than light. I think it has.
> "
>
> So if press a button with the same signal characteristics as the LPF pulse,
> and if I use the above setup to detect the pulse and explode a bomb, the
> bomb will explode earlier than if the pulse propagated at the speed of
> light. The pressing of the button (Action) results in the exploding of a
> bomb (Reaction) faster than light speed. This is clear cause and effect
> (information) which propagtes faster than light.
>
>
> William

How did the input "pulse" get bandlimited in the first place?   This is 
key to understanding how this works.  It's not magic, information is not 
accelerated.

Imagine this and you might be able to see what's going on:

Start with an ideal impulse, a dirac delta, or some suitable equivalent. 
  Pass that impulse through your bandlimiting filter, see how long it 
takes to come out.   Since the bandlimiting filter is causal, the bottom 
of the leading edge of the pulse doesn't happen until the instantaneous 
impulse has arrived.  The entire width of the output pulse is then a 
delay from the incidence of the impulse.

Consider the dirac delta the "information".

So, it is easy to see that the peak of the output pulse has, at minimum, 
the delay from the bottom of the leading edge of the bandlimited output 
pulse.

If you closely examine the output of the predictive filters, whether 
it's a filter with a negative group delay or the near field of an 
antenna or whatever, it does NOT begin to ramp up the output pulse 
values until the input pulse values have actually arrived.  In other 
words, as we know, or at least most of us know, such a filter is still 
causal and does NOT predict the onset of the leading edge of the pulse.

So, what you are seeing is, for example, because I don't know the actual 
numbers from the simulations, the distance from the initial dirac delta 
to the bandlimited output pulse peak being X, and the "accelerated", 
predicted pulse output is X-delta, where delta is the small advance 
achieved by the prediction.  NOTE THAT X-delta IS STILL A POSITIVE 
NUMBER, and delta is going to be small compared to X.

All filters have delay.  What you are seeing is that the predictive 
filter has a little less delay than the signal being compared to it. 
The "information" arrival, as compared to the actual incidence of the 
initial dirac delta, will not violate causality or c.  Observers can be 
fooled, however, as you are demonstrating.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Eric Jacobsen wrote:
> On 3/29/2010 8:42 AM, WWalker wrote:
>> Eric,
>>
>> Could you elaboate on your comment below. I think we need to agree on the
>> definition of information in regards to the LPF pulsed carrier 
>> simulation.
>> How does your comment refute my argument presented again below?
>>
>>> I suppose you can argue semantics here about what defines the "pulse",
>>
>> Again I claim:
>>
>> "Refering to the Low Pass Filtered Pulse
>> simulation I posted, the simulation clearly shows that if I transmit a
>> pulse, the pulse edge arrives sooner than if it had propagated faster 
>> than
>> light. If my detector at the receiving end is a threshold detector which
>> is
>> set to look for anything above the noise level, it will fire earlier than
>> if the pulse had propagated at light speed. In other words, it shows that
>> if I push a button launching the narrowband pulse signal and propagate it
>> via a dipole to a nearfield receiver with the threshold detector, the
>> pressed button will be detected sooner than a light propagated signal.
>> This
>> clearly shows that an action (informaton) in this nearfield dipole system
>> can be detected faster than light. If this is true than I have proven my
>> point that information propagtes faster than light in the nearfield of a
>> dipole."
>>
>> "it does not matter what the reason is. If I have
>> a communication link that allows me to transmit a pulse over a distance
>> faster than a light propagated pulse, then the pulse propagates faster
>> than
>> light. If I use the pulse to denonate a bomb located a distance away, the
>> bomb will explode sooner than if the pulse propagated at the speed of
>> light. This is absolutly true and cannot be argued. The only question is
>> if
>> the dipole simulation demonstrates that a pulse can be detected over a
>> distance faster than light. I think it has.
>> "
>>
>> So if press a button with the same signal characteristics as the LPF 
>> pulse,
>> and if I use the above setup to detect the pulse and explode a bomb, the
>> bomb will explode earlier than if the pulse propagated at the speed of
>> light. The pressing of the button (Action) results in the exploding of a
>> bomb (Reaction) faster than light speed. This is clear cause and effect
>> (information) which propagtes faster than light.
>>
>>
>> William
> 
> How did the input "pulse" get bandlimited in the first place?   This is 
> key to understanding how this works.  It's not magic, information is not 
> accelerated.
> 
> Imagine this and you might be able to see what's going on:
> 
> Start with an ideal impulse, a dirac delta, or some suitable equivalent. 
>  Pass that impulse through your bandlimiting filter, see how long it 
> takes to come out.   Since the bandlimiting filter is causal, the bottom 
> of the leading edge of the pulse doesn't happen until the instantaneous 
> impulse has arrived.  The entire width of the output pulse is then a 
> delay from the incidence of the impulse.
> 
> Consider the dirac delta the "information".
> 
> So, it is easy to see that the peak of the output pulse has, at minimum, 
> the delay from the bottom of the leading edge of the bandlimited output 
> pulse.
> 
> If you closely examine the output of the predictive filters, whether 
> it's a filter with a negative group delay or the near field of an 
> antenna or whatever, it does NOT begin to ramp up the output pulse 
> values until the input pulse values have actually arrived.  In other 
> words, as we know, or at least most of us know, such a filter is still 
> causal and does NOT predict the onset of the leading edge of the pulse.
> 
> So, what you are seeing is, for example, because I don't know the actual 
> numbers from the simulations, the distance from the initial dirac delta 
> to the bandlimited output pulse peak being X, and the "accelerated", 
> predicted pulse output is X-delta, where delta is the small advance 
> achieved by the prediction.  NOTE THAT X-delta IS STILL A POSITIVE 
> NUMBER, and delta is going to be small compared to X.
> 
> All filters have delay.  What you are seeing is that the predictive 
> filter has a little less delay than the signal being compared to it. The 
> "information" arrival, as compared to the actual incidence of the 
> initial dirac delta, will not violate causality or c.  Observers can be 
> fooled, however, as you are demonstrating.

That's good analysis. Another way to show this with signals that can be 
more easily (at least less contentiously) constructed than an impulse is 
with a square pulse and an L-C delay line of the kind used at the input 
of many analog oscilloscopes. (Such a delay line is a low-pass filter.) 
Although the shape of the input pulse is quite well preserved and the 
delay is evident, close examination shows that "preringing" begins soon 
after the input pulse is applied, well before the main pulse appears at 
the output.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

Rune,

Now you are being rediculus! The dipole solution has been derived hundreds
of times in hundreds of ways over the last 100 years. They all agree with
the transfer function I used in my simulation, and agree that the solution
is valid in the nearfield provided the distance to the analysis point is
much less than the length of the dipole. It has also been derived using
spherical harmonics resulting in the same result (Ref. Electrodynamics,
James Blake Westgard, 1997). I have also derived the solution from
Maxwell's Equations in my paper, and I have also measured the dispersion of
a real magnetic dipole antenna with a RF Network Analyser and I get the
same nonlinear nearfield phase vs frequency curve. So the effect is clearly
real. 

William






>On 29 Mar, 17:06, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Rune,
>>
>> The transfer function I use in my simulations is well known for the
>> magnetic field component of an electric dipole: (1/r^2)e^(ikr)[ikr-1].
You
>> can look this up in any EM book or look at my paper Eq. 46 were I have
>> derived it from Maxwell Equations,
>
>Neither the textbooks nor you have derived anything.
>You (and the textbooks) refer to tabulated approimation
>you don't understand how were derived, or the extent
>of their validity.
>
>The key to pinning down the causes of your incompetence
>is to derive the results from scratch. I have already
>told you how to do this in a different post.
>
>> It is well known and stated clearly in most text books that the model
is
>> only valid provided the distance to the observation point is much
larger
>> than the dipole length.
>
>Again: Your problem is that you don't understand the basics.
>Start with the monople. The results you have "derived" are
>only valid in the far field of the monoploe (which, of course,
>you would have known had you *read* my previous posts). Once
>you understand it fully, you might advance to the dipole.
>
>As I said before: Your ego is your problem. There is no point
>refering or listiong results if you don't contemplate their
>impact and consequences. You have demonstrated a unique
>ability *not* to think.
>
>You will not get anywhere unless you acknowledge that fact.
>
>Rune
>

Eric Jacobsen <eric.jacobsen@ieee.org> wrote:
(big snip)
 
> How did the input "pulse" get bandlimited in the first place?   This is 
> key to understanding how this works.  It's not magic, information is not 
> accelerated.
 
> Imagine this and you might be able to see what's going on:
 
> Start with an ideal impulse, a dirac delta, or some suitable equivalent. 
>  Pass that impulse through your bandlimiting filter, see how long it 
> takes to come out.   Since the bandlimiting filter is causal, the bottom 
> of the leading edge of the pulse doesn't happen until the instantaneous 
> impulse has arrived.  The entire width of the output pulse is then a 
> delay from the incidence of the impulse.
 
> Consider the dirac delta the "information".

Well, that doesn't seem quite fair.  If you take the output of
the filter, and then pass it through the transmit/receive system,
and then determine the delay, that seems a better test.  But...
 
> So, it is easy to see that the peak of the output pulse has, at minimum, 
> the delay from the bottom of the leading edge of the bandlimited output 
> pulse.
 
> If you closely examine the output of the predictive filters, whether 
> it's a filter with a negative group delay or the near field of an 
> antenna or whatever, it does NOT begin to ramp up the output pulse 
> values until the input pulse values have actually arrived.  In other 
> words, as we know, or at least most of us know, such a filter is still 
> causal and does NOT predict the onset of the leading edge of the pulse.

There are reference in the Wikipedia page to an experiment by Boyd
that seems to show faster than light behavior for, not surprisingly,
light!  (It also does not claim to violate special relativity.)
The experiment uses erbium doped optical fibers.  As well as
I understand it, the fiber amplifies the incoming signal and,
slightly later, generates a signal to cancel the rest of the
incoming signal.

My best thought in terms of analog electronics is to consider
a very high gain amplifier with an insufficient power supply.
Say, for example, with filter capacitors that charge through
a large resistor.  Now, when the leading edge of the pulse comes
in it will be amplified by a large factor, resulting in a new
pulse.  By the time the peak arrives, the filter capacitors
have discharged, and the output no longer follows the input.

I believe that isn't so far from what is done with erbium 
doped fiber.  The erbium atoms are put into a higher energy
state, and then the signal comes in.  A Gaussian envelope
wave train has a nice, oscillatory, leading edge ready to
cause the erbium to emit well before the peak.

To me, a better test is to do a correlation between the input
and output for an appropriately band limited noise source.
(Maybe white noise through an appropriate filter.)  The
peak in the correlation integral indicates the delay, on average, 
through the system.  Measuring the delay of a single transition,
or peak, can too easily give the wrong value.

-- glen 

r b-j,

But, the research presented in this thread indicates that the EM signal
speed in vaccuum is faster than light in the nearfield and only reduces to
the speed of light in the farfield. If this is true, then in your opinion,
how would this affect physics? As you said, a lot of physics is based on
the speed of light being constant, but what if it is not?

William   

>On Mar 28, 4:13=A0pm, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
>> On 3/28/2010 11:40 AM, WWalker wrote:
>>
>> > I am sorry to insist, but it does not matter what the reason is. =A0If
=
>I have
>> > a communication link that allows me to transmit a pulse over a
distance
>> > faster than a light propagated pulse, then the pulse propagates faster
=
>than
>> > light.
>>
>> I suppose you can argue semantics here about what defines the "pulse",
>> but understand that "information" is not propagating faster than light
>> in any of the examples, and neither is energy. =A0This seems to be the
ke=
>y
>> point that must be understood. =A0 A simple small phase advance of a
>> signal is NOT indicative of information exceeding the speed of light.
>>
>> If you just want to claim that the signal has phase advanced and
appears
>> to arrive earlier than expected, that's fine, I don't think anyone will
>> argue with you there. =A0That's what has led to discussion and study on
>> this topic in many places.
>>
>> > If I use the pulse to denonate a bomb located a distance away, the
>> > bomb will explode sooner than if the pulse propagated at the speed of
>> > light. This is absolutely true and cannot be argued.
>
>well, it *is* argued.
>
>this is funny, because i have been in similar discussions but on
>sci.physics.research or sci.physics.foundations or, in the past, the
>Physics Forums site.  i haven't seen it here on comp.dsp.  sometimes
>the discussion is about the speed of gravity (in comparison to the
>speed of electromagnetic propagation a.k.a. "speed of light").  now, i
>*do* seem to remember reading something about the group velocity of
>some modulated light source exceeding the phase velocity in some
>medium.  i don't usually concern myself with non-vacuum propagation
>since, at the atomic level, it's a vacuum between the atoms and when
>epsilon differs from epsilon_0 it's a macroscopic *aggregate* effect
>of the polarization of molecules in the medium.  same with mu and
>mu_0.
>
>the speed of light (or of EM) in a vacuum, what we call "c", is not a
>property of E&M, but is a property of space and time.  it doesn't
>matter what the "instantaneous" force or interaction is.  could be EM,
>gravity, strong (turns out weak is mediated by particles with mass, so
>it ain't as instantaneous).
>
>suppose you are standing there and i am standing here, some distance
>away.  now suppose you are holding a big negative charge and i am
>holding a big positive charge and we are both restricting the movement
>of our charges to a plane that is perpendicular to the line connecting
>the two of us.  since our charges are attracted to each other, when i
>move my charge up, your charge follows it up.  if i move it down, your
>charge follows it down.  if i move it to my right, your charge follows
>it to your left (assuming we are facing each other).  similarly if i
>move my charge to my left, your charge follows to your right.  if i
>move my charge up and down repeatedly, yours will follow it up and
>down repeatedly.  i am literally a "transmitting antenna" and you are
>a "receiving antenna".  if i move my charge up and down a million
>times per second, you could tune it in with an AM radio.  if i move it
>left and right 100 million times per second, you can tune it in with
>an FM radio.  if i move it back and forth 500 trillion times per
>second, you would see it as a blur of orange color.  that's what EM
>radiation is, at a fundamental level.
>
>now imagine there is a third party observing us at a distance and is
>equidistant from us both.  and suppose this third party knows, from
>some other means, what the distance is between us. no matter what i do
>with the charge, when the observer sees the perturbation of position
>on my end and then observes a perturbation at your end, the time
>differential between the cause and effect will always be that distance
>between us divided by c.  i don't care what you read or what you think
>W, that's what it is.
>
>it would be the same if you and i were the size of gods and, instead
>of charges, i was holding a planet and you were holding a planet.  i
>perturb the position of my planet and your planet will get disturbed
>by that change of gravitational field and the time differential
>between the disturber and disturbed will be the distance between the
>two of us divided by the *same* c.  so, even if we tried to use
>gravity waves to communicate information, we would still be limited by
>the speed c.
>
>now, despite what we sometimes read, it isn't that Nature is imposing
>a fundamental limit to the speed of propagation of information, it's
>that Nature, namely the fundamental nature of space and time, imposes
>a finite limit of speed of the fundamental interactions, of which all
>of physical reality is built upon.  *that* is what imposes a limit of
>speed of conveyance of information since information is conveyed by a
>physical interaction.
>
>there is nothing magical about that speed "c".  all the physics needs
>is that c is real, positive, and finite.  it could be *any* speed (as
>observed by a god-like observer who is not himself affected by the
>physics).  for those of us who are mortal and are governed by the
>interactions of Nature, all of the rest of reality would be scaled in
>such a way that the speed of propagation, c, would appear to be the
>same, *unless* some *dimensionless* fundamental physical constant
>(like alpha) changes.  and then, the salient fact is that this
>dimensionless "constant" changed (not c).  we don't measure or
>perceive dimensionful quantities directly, but we *always* measure or
>perceive such as a ratio against a reference quantity of the same
>dimension.  there is always a reference voltage in our DVM, there are
>always pre-existing tick marks on our ruler.  the dimensionful
>quantity we call "c" is more of an expression of the anthropometric
>units we happen to be using to measure length and time.
>
>WWalker, i might suggest that you take this up at
>sci.physic.foundations or maybe sci.physics.research (both are
>moderated) or go to the PhysicsForums.com site.
>
>r b-j
>

Jerry,

Dopler radar is used to measure object velocity and if this is done in a
particle accelerator experiments, the results could be missleading if not
interpreted correctly. In addition, my analysis has shown that fields
generated by a dipole source never achieve a constant velocity, they just
approach it in the farfield. So doppler measurements in the farfield will
differ also by a small amount. As farfield dopler radar becomes more
sensitive it will eventially have to deal with the effects I am
discussing.

William



>WWalker wrote:
>> Jerry,
>> 
>> The speed of light is a corner stone in physics and if it is not a
constant
>> then many of our theories in physics will be affected. There may be
direct
>> practical uses as well, but I just guessing: improving accuracy of high
>> speed doppler radar, speeding up communication to spacecraft where time
>> delays are problematic, increasing speed of computers when they are
>> eventually limited by light speed delays etc. As I said, these are only
>> guesses, the main effect would be a change in many of our theories in
>> physics, which would eventually lead to new practical uses and
>> technologies.
>> 
>> William 
>
>How much Doppler radar is done within half a wavelength of the antenna? 
>One might as well use a tape measure for distance, and if the Doppler 
>shift amounts to anything, duck!
>
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>

Eric,

The first pulse is not the signal fed to the dipole. The first pulse is
just used to create a narrow banded pulse, which is then sent through the
dipole to be detected. Forget about the first pulse, the question is if I
send a narrow banded pulse through the dipole how long will it take to
arrive across a region of space in the nearfield of the dipole. If the
answer is less than the speed of light to cross the same region of space,
then the pulse has propagated faster than light. 

"So if press a button with the same signal characteristics as the LPF
pulse, and if I use the threshold detector set jsut above the noise level 
to detect the pulse and explode a bomb, the bomb will explode earlier than
if the pulse propagated at the speed of light. The pressing of the button
(Action) results in the exploding of a bomb (Reaction) faster than light
speed. This is clear cause and effect (information) which propagtes faster
than light."  
 

William

>On 3/29/2010 8:42 AM, WWalker wrote:
>> Eric,
>>
>> Could you elaboate on your comment below. I think we need to agree on
the
>> definition of information in regards to the LPF pulsed carrier
simulation.
>> How does your comment refute my argument presented again below?
>>
>>> I suppose you can argue semantics here about what defines the "pulse",
>>
>> Again I claim:
>>
>> "Refering to the Low Pass Filtered Pulse
>> simulation I posted, the simulation clearly shows that if I transmit a
>> pulse, the pulse edge arrives sooner than if it had propagated faster
than
>> light. If my detector at the receiving end is a threshold detector
which
>> is
>> set to look for anything above the noise level, it will fire earlier
than
>> if the pulse had propagated at light speed. In other words, it shows
that
>> if I push a button launching the narrowband pulse signal and propagate
it
>> via a dipole to a nearfield receiver with the threshold detector, the
>> pressed button will be detected sooner than a light propagated signal.
>> This
>> clearly shows that an action (informaton) in this nearfield dipole
system
>> can be detected faster than light. If this is true than I have proven
my
>> point that information propagtes faster than light in the nearfield of
a
>> dipole."
>>
>> "it does not matter what the reason is. If I have
>> a communication link that allows me to transmit a pulse over a distance
>> faster than a light propagated pulse, then the pulse propagates faster
>> than
>> light. If I use the pulse to denonate a bomb located a distance away,
the
>> bomb will explode sooner than if the pulse propagated at the speed of
>> light. This is absolutly true and cannot be argued. The only question
is
>> if
>> the dipole simulation demonstrates that a pulse can be detected over a
>> distance faster than light. I think it has.
>> "
>>
>> So if press a button with the same signal characteristics as the LPF
pulse,
>> and if I use the above setup to detect the pulse and explode a bomb,
the
>> bomb will explode earlier than if the pulse propagated at the speed of
>> light. The pressing of the button (Action) results in the exploding of
a
>> bomb (Reaction) faster than light speed. This is clear cause and effect
>> (information) which propagtes faster than light.
>>
>>
>> William
>
>How did the input "pulse" get bandlimited in the first place?   This is 
>key to understanding how this works.  It's not magic, information is not 
>accelerated.
>
>Imagine this and you might be able to see what's going on:
>
>Start with an ideal impulse, a dirac delta, or some suitable equivalent. 
>  Pass that impulse through your bandlimiting filter, see how long it 
>takes to come out.   Since the bandlimiting filter is causal, the bottom 
>of the leading edge of the pulse doesn't happen until the instantaneous 
>impulse has arrived.  The entire width of the output pulse is then a 
>delay from the incidence of the impulse.
>
>Consider the dirac delta the "information".
>
>So, it is easy to see that the peak of the output pulse has, at minimum, 
>the delay from the bottom of the leading edge of the bandlimited output 
>pulse.
>
>If you closely examine the output of the predictive filters, whether 
>it's a filter with a negative group delay or the near field of an 
>antenna or whatever, it does NOT begin to ramp up the output pulse 
>values until the input pulse values have actually arrived.  In other 
>words, as we know, or at least most of us know, such a filter is still 
>causal and does NOT predict the onset of the leading edge of the pulse.
>
>So, what you are seeing is, for example, because I don't know the actual 
>numbers from the simulations, the distance from the initial dirac delta 
>to the bandlimited output pulse peak being X, and the "accelerated", 
>predicted pulse output is X-delta, where delta is the small advance 
>achieved by the prediction.  NOTE THAT X-delta IS STILL A POSITIVE 
>NUMBER, and delta is going to be small compared to X.
>
>All filters have delay.  What you are seeing is that the predictive 
>filter has a little less delay than the signal being compared to it. 
>The "information" arrival, as compared to the actual incidence of the 
>initial dirac delta, will not violate causality or c.  Observers can be 
>fooled, however, as you are demonstrating.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

WWalker <william.walker@n_o_s_p_a_m.imtek.de> wrote:
 
> The first pulse is not the signal fed to the dipole. The first pulse is
> just used to create a narrow banded pulse, which is then sent through the
> dipole to be detected. Forget about the first pulse, the question is if I
> send a narrow banded pulse through the dipole how long will it take to
> arrive across a region of space in the nearfield of the dipole. If the
> answer is less than the speed of light to cross the same region of space,
> then the pulse has propagated faster than light. 
 
> "So if press a button with the same signal characteristics as the LPF
> pulse, and if I use the threshold detector set jsut above the noise level 
> to detect the pulse and explode a bomb, the bomb will explode earlier than
> if the pulse propagated at the speed of light. The pressing of the button
> (Action) results in the exploding of a bomb (Reaction) faster than light
> speed. This is clear cause and effect (information) which propagtes faster
> than light."  

OK, back to Eric's comments.

Note that the narrow band signal necessarily has a slow rise time.
(If not, it wouldn't be narrow.)  The begninning of the rising
edge can't come before you push the button, and the peak will come
sometime later.  If you measure from button push to bomb explode,
then you will find an appropriately long delay.

If you measure from pulse peak to bomb explode, then it might
be shorter than you believe it could be.

Look at: A. Schweinsberg et al, 2006 Europhys. Lett 73, 218

-- glen

On 29 Mar, 23:25, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> Now you are being rediculus! The dipole solution has been derived hundreds
> of times in hundreds of ways over the last 100 years.

As I said, you are totally incompetent. The number of times
a solution has been derived is irrelevant. Whether it is correct
or not, makes all the difference in the world. Th eexpressions
you use are wrong in the near field.

Answer me this: If the solution relies on the trivial exponential
functions - why do you spend time and space on discussing Bessel
functions?

You don't know, because you haven't contemplated what happens.
You are merely a mysticist who thinks that reciting the prescribed
formulas is enough.

Rune

On 3/29/2010 3:15 PM, WWalker wrote:
> Eric,
>
> The first pulse is not the signal fed to the dipole. The first pulse is
> just used to create a narrow banded pulse, which is then sent through the
> dipole to be detected. Forget about the first pulse, the question is if I
> send a narrow banded pulse through the dipole how long will it take to
> arrive across a region of space in the nearfield of the dipole. If the
> answer is less than the speed of light to cross the same region of space,
> then the pulse has propagated faster than light.
>
> "So if press a button with the same signal characteristics as the LPF
> pulse, and if I use the threshold detector set jsut above the noise level
> to detect the pulse and explode a bomb, the bomb will explode earlier than
> if the pulse propagated at the speed of light. The pressing of the button
> (Action) results in the exploding of a bomb (Reaction) faster than light
> speed. This is clear cause and effect (information) which propagtes faster
> than light."
>
>
> William

Okay, if you can't follow that argument (although it's still correct, 
the narrow-band pulse peak isn't the information, or it's rise time 
would be non-causal), then, as Glen pointed out, use your button push.

If the button push is represented with an ideal impulse or a step 
function, the rise time is the same (i.e., infinite).  The narrow-band, 
filtered  representation of either an impulse or a step signal will have 
delay, and the rise time will be proportional to the delay.  The 
narrower the filter, the longer the delay.

The bandlimitation allows the possibility of prediction due to the 
redundancy in the signal.  Again, the same argument as before applies. 
  The delay through the bandlimiting filter (of the step response of the 
button push) is X, a filter with negative group delay or other similar 
predictive capability has a delay of X-delta WHICH IS STILL A POSITIVE 
NUMBER.

Measuring from the button push (or the incidence of an impulse, IT DOES 
NOT MATTER), there will not be any acceleration of propagation beyond c, 
just a reduction in filter delay in the predictive case.  You can go 
back a couple of days and many posts and see people suggesting to you to 
measure either from signal onset or signal interruption, but you seem 
unwilling to do this.  I suspect you know what the result will be and 
just refuse to let go of your theory.

These are relatively simple arguments, especially to somebody who 
insists on a competence level high enough to claim such an unlikely 
explanation as exceeding c.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

WWalker wrote:
> Eric,
> 
> The first pulse is not the signal fed to the dipole. The first pulse is
> just used to create a narrow banded pulse, which is then sent through the
> dipole to be detected. Forget about the first pulse, the question is if I
> send a narrow banded pulse through the dipole how long will it take to
> arrive across a region of space in the nearfield of the dipole. If the
> answer is less than the speed of light to cross the same region of space,
> then the pulse has propagated faster than light. 
> 
> "So if press a button with the same signal characteristics as the LPF
> pulse, and if I use the threshold detector set jsut above the noise level 
> to detect the pulse and explode a bomb, the bomb will explode earlier than
> if the pulse propagated at the speed of light. The pressing of the button
> (Action) results in the exploding of a bomb (Reaction) faster than light
> speed. This is clear cause and effect (information) which propagtes faster
> than light."  

Over what distance?

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On Mar 29, 5:36=A0pm, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> r b-j,
>
> But, the research presented in this thread indicates that the EM signal
> speed in vaccuum is faster than light in the nearfield and only reduces t=
o
> the speed of light in the farfield. If this is true, then in your opinion=
,
> how would this affect physics? As you said, a lot of physics is based on
> the speed of light being constant, but what if it is not?

speed of light, relative to what?

the variation of a dimensionful quantity IN AND OF ITSELF is
meaningless.

the speed of light is always one Planck length per Planck time.

now if the number of Planck lengths in the Bohr radius changes, that's
a dimensionless quantity and a change thereof means something and we
would know the difference.  the relative size of platinum and iridium
atoms to the Bohr radius is a dimensionless quantity and if that
changed, it would mean something.  the number of platinum and iridium
atoms between two scratch marks on the prototype meter in Sevres is a
dimensionless number and if that changed appreciably, we would know it
(and that meter stick would not be a particularly good meter stick).
so the number of Planck lengths in a meter (assuming we revert the
definition to what it was in 1959) is a dimensionless quantity and its
variation is meaningful.

there's a similar song and dance regarding the Planck time and the
second.

if the number of meters (these would be ca. 1959 meters) traveled by
light in the time elapsed by one second has appears to change from
299792458, then it's because one of those *dimensionless* quantities
has changed. the number of current meters (post 1983) in one second of
light cannot change, simply from how the meter is defined.

another reference to look at is Michael Duff: http://arxiv.org/abs/hep-th/0=
208093

maybe also take a look at the Wikipedia articles about the subject:
http://en.wikipedia.org/wiki/Faster-than-light
http://en.wikipedia.org/wiki/Variable_speed_of_light
http://en.wikipedia.org/wiki/Scharnhorst_effect

this is a fundamental physical concept.  it is not superceded by
anything you're writing at the Los Alamos arXiv site (i think Duff
would argue that the acceptance threshold for arXiv is low, compared
to longstanding reputable journals, but with the Bogdanov Affair,
anything is possible).  don't believe me?  then take it up on a
physics newsgroup.  those guys at s.p.r will set you straight (ask for
John Baez or Steve Carlip).

r b-j

>Steve,
>
>Clearly energy is also propagating faster than light in the dipole
system.
>If the pulsed carrier is propagating faster than light, as shown in my
>simulaton, then the energy of this signal is just the signal squared and
>low pass filtered. This is exactly how I detected the signal in my
>simulation. So the detected pulse I showed in my simulation is also
>proportional to the energy.   
>
>William  

Squaring a signal to derive the power is based on assumptions about phase
relationships. You are *inferring* power propagation. You are not
demonstrating it.

Steve

Eric,

I agree that if the signal starts before the first filter and is then low
pass filtered, the time delay of the signal is the propagation time plus
the time delay of the filter. But what if the bandwidth limited signal is
created directly without a low pass filter, then the the time delay is just
the propagation time. For example, if the signal is created by a voltage
source that is manualy slowly adjusted, such that the bandwidth is limited,
and if the signal is then mixed with a carrier and sent though a nearfield
dipole system, then the detected envelope will arrive earlier than a light
propagated signal as I showed in my simulation. Each voltage point on the
voltage vs time curve of the voltage source is information about what the
voltage was at that time. If that pattern is reproduced exactly a distance
away, then the time delay of each information point is the propagation time
of the information.

William  




>On 3/29/2010 3:15 PM, WWalker wrote:
>> Eric,
>>
>> The first pulse is not the signal fed to the dipole. The first pulse is
>> just used to create a narrow banded pulse, which is then sent through
the
>> dipole to be detected. Forget about the first pulse, the question is if
I
>> send a narrow banded pulse through the dipole how long will it take to
>> arrive across a region of space in the nearfield of the dipole. If the
>> answer is less than the speed of light to cross the same region of
space,
>> then the pulse has propagated faster than light.
>>
>> "So if press a button with the same signal characteristics as the LPF
>> pulse, and if I use the threshold detector set jsut above the noise
level
>> to detect the pulse and explode a bomb, the bomb will explode earlier
than
>> if the pulse propagated at the speed of light. The pressing of the
button
>> (Action) results in the exploding of a bomb (Reaction) faster than
light
>> speed. This is clear cause and effect (information) which propagtes
faster
>> than light."
>>
>>
>> William
>
>Okay, if you can't follow that argument (although it's still correct, 
>the narrow-band pulse peak isn't the information, or it's rise time 
>would be non-causal), then, as Glen pointed out, use your button push.
>
>If the button push is represented with an ideal impulse or a step 
>function, the rise time is the same (i.e., infinite).  The narrow-band, 
>filtered  representation of either an impulse or a step signal will have 
>delay, and the rise time will be proportional to the delay.  The 
>narrower the filter, the longer the delay.
>
>The bandlimitation allows the possibility of prediction due to the 
>redundancy in the signal.  Again, the same argument as before applies. 
>  The delay through the bandlimiting filter (of the step response of the 
>button push) is X, a filter with negative group delay or other similar 
>predictive capability has a delay of X-delta WHICH IS STILL A POSITIVE 
>NUMBER.
>
>Measuring from the button push (or the incidence of an impulse, IT DOES 
>NOT MATTER), there will not be any acceleration of propagation beyond c, 
>just a reduction in filter delay in the predictive case.  You can go 
>back a couple of days and many posts and see people suggesting to you to 
>measure either from signal onset or signal interruption, but you seem 
>unwilling to do this.  I suspect you know what the result will be and 
>just refuse to let go of your theory.
>
>These are relatively simple arguments, especially to somebody who 
>insists on a competence level high enough to claim such an unlikely 
>explanation as exceeding c.
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Jerry,

The propagation distance in my 500MHz carrier simmulation is 10cm. But the
distance can be a lot larger for lower carrier frequencies. For example, if
the carrier frequency (fc) is 1MHz (typical AM radio) then the optimum
propagation distance is 300m (1/6 carrier wavelength) and the envelope will
arrive 80ns earlier than a light speed (propagating envelope (0.08/fc). For
lower carrier frequencies, even larger distances and larger light speed
time differences are possible.

William



>WWalker wrote:
>> Eric,
>> 
>> The first pulse is not the signal fed to the dipole. The first pulse is
>> just used to create a narrow banded pulse, which is then sent through
the
>> dipole to be detected. Forget about the first pulse, the question is if
I
>> send a narrow banded pulse through the dipole how long will it take to
>> arrive across a region of space in the nearfield of the dipole. If the
>> answer is less than the speed of light to cross the same region of
space,
>> then the pulse has propagated faster than light. 
>> 
>> "So if press a button with the same signal characteristics as the LPF
>> pulse, and if I use the threshold detector set jsut above the noise
level 
>> to detect the pulse and explode a bomb, the bomb will explode earlier
than
>> if the pulse propagated at the speed of light. The pressing of the
button
>> (Action) results in the exploding of a bomb (Reaction) faster than
light
>> speed. This is clear cause and effect (information) which propagtes
faster
>> than light."  
>
>Over what distance?
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

Steve,

If I place a grounded resistor (R) on the output of the nearfield dipole
dectector, then the signal voltage (V) will be converted to a current (I)
with the same signal shape as the transmitted signal. The power is        
I*V = V^2/R and the energy is the the average power. This result is
proportional to how I demodulated my signal in my posted simulation, where
I squared the signal and low pass filtered it.  

William

 

>>Steve,
>>
>>Clearly energy is also propagating faster than light in the dipole
>system.
>>If the pulsed carrier is propagating faster than light, as shown in my
>>simulaton, then the energy of this signal is just the signal squared and
>>low pass filtered. This is exactly how I detected the signal in my
>>simulation. So the detected pulse I showed in my simulation is also
>>proportional to the energy.   
>>
>>William  
>
>Squaring a signal to derive the power is based on assumptions about phase
>relationships. You are *inferring* power propagation. You are not
>demonstrating it.
>
>Steve
>
>

Rune, 

You are using insults and ridicule as arguments. Are you afraid to discuss
this topic rationally? You obviously know a lot and I am sure you can
contribute. Why don't you join us in the discussion. 

I told you I have measured the nonlinear phase responce of a magnetic
dipole antenna using a RF Network analyser and it matches very well with
the curve in figure 9 of my paper, also in the Sten Paper a NEC simulation
shows the same results (Figure 3). There is no need to doubt the theory if:
theory, simmulation, and experiment match.

William





>On 29 Mar, 23:25, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Rune,
>>
>> Now you are being rediculus! The dipole solution has been derived
hundreds
>> of times in hundreds of ways over the last 100 years.
>
>As I said, you are totally incompetent. The number of times
>a solution has been derived is irrelevant. Whether it is correct
>or not, makes all the difference in the world. Th eexpressions
>you use are wrong in the near field.
>
>Answer me this: If the solution relies on the trivial exponential
>functions - why do you spend time and space on discussing Bessel
>functions?
>
>You don't know, because you haven't contemplated what happens.
>You are merely a mysticist who thinks that reciting the prescribed
>formulas is enough.
>
>Rune
>

WWalker wrote:
> Steve,
> 
> If I place a grounded resistor (R) on the output of the nearfield dipole
> dectector, then the signal voltage (V) will be converted to a current (I)
> with the same signal shape as the transmitted signal. The power is        
> I*V = V^2/R and the energy is the the average power. This result is
> proportional to how I demodulated my signal in my posted simulation, where
> I squared the signal and low pass filtered it.  
> 
> William
> 
>  
> 
>>> Steve,
>>>
>>> Clearly energy is also propagating faster than light in the dipole
>> system.
>>> If the pulsed carrier is propagating faster than light, as shown in my
>>> simulaton, then the energy of this signal is just the signal squared and
>>> low pass filtered. This is exactly how I detected the signal in my
>>> simulation. So the detected pulse I showed in my simulation is also
>>> proportional to the energy.   
>>>
>>> William  
>> Squaring a signal to derive the power is based on assumptions about phase
>> relationships. You are *inferring* power propagation. You are not
>> demonstrating it.

That's a leap needing justification. The E and H fields are in 
quadrature in the far field; thus the Poynting vector is normal to the 
wavefront and real power is conveyed. If I recall correctly, E and H are 
in phase in the near field and "power" is imaginary. Whatever power is 
developed in your resistor comes from the field being warped by the 
receiver, so the equations you use don't apply to the simulation.

Jerry
-- 
Discovery consists of seeing what everybody has seen, and thinking what
nobody has thought.    .. Albert Szent-Gyorgi
�����������������������������������������������������������������������

On Mar 29, 12:18=A0pm, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Jerry,
>
> The speed of light is a corner stone in physics and if it is not a consta=
nt
> then many of our theories in physics will be affected. There may be direc=
t
> practical uses as well, but I just guessing: improving accuracy of high
> speed doppler radar, speeding up communication to spacecraft where time
> delays are problematic, increasing speed of computers when they are
> eventually limited by light speed delays etc. As I said, these are only
> guesses, the main effect would be a change in many of our theories in
> physics, which would eventually lead to new practical uses and
> technologies.
>
> William
>
>
>
> >Eric Jacobsen wrote:
>
> > =A0 ...
>
> >> I think until you can demonstrate something like that the more likely
> >> explanation of bandlimited prediction would be expected to prevail.
>
> >Even allowing the unlikely possibility that the 6-degree phase advance
> >*in the near field* represents a real speed increase, and that the
> >"pulse" in the far field is expected to show no advance at all, What
> >practical use can this have?
>
> >Jerry
> >--
> >Discovery consists of seeing what everybody has seen, and thinking what
> >nobody has thought. =A0 =A0.. Albert Szent-Gyorgi
> >- Hide quoted text -
>
> - Show quoted text -

Hello William,

I suggest you 1st study the EPR paradox and then look up Bell's
theorem and see how it applies to Relativity. You are not going to get
information over any significant distance with superluminal speed.
Sure there is a probability that a particle will travel faster than
light for a short distance (say for example across the nucleus of an
atom about 10^-14 to 10^-15 meters) but when you start to add up all
of the paths in a Feynman diagram, you will see the probability of it
happening across a room is not even likely in a time period of the age
of the Universe.

Clay

On 3/30/2010 9:56 AM, WWalker wrote:
> Rune,
>
> You are using insults and ridicule as arguments. Are you afraid to discuss
> this topic rationally? You obviously know a lot and I am sure you can
> contribute. Why don't you join us in the discussion.
>
> I told you I have measured the nonlinear phase responce of a magnetic
> dipole antenna using a RF Network analyser and it matches very well with
> the curve in figure 9 of my paper, also in the Sten Paper a NEC simulation
> shows the same results (Figure 3). There is no need to doubt the theory if:
> theory, simmulation, and experiment match.
>
> William

I'm curious as to how you characterized the antenna with an RF NA.  I'd 
think that would be an extremely difficult thing to do properly. 
Antenna characterization takes some careful work and usually a special 
facility.  Even then it's difficult.


-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

On 30 Mar, 18:56, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Rune,
>
> You are using insults and ridicule as arguments.

I am stating facts. If you find the facts insulting, you might
want to change them - e.g. by learning the bascis of the subjects
you pretend to discuss.

> Are you afraid to discuss
> this topic rationally?

A rational discussion requires a rational party. Somebody who

1) States he can make information travel faster than the speed
   of light and only provides a numerical simulation as evidence
2) Claims, apparently in earnest, that he thinks the dipole is
   "difficult material"

doesn't exactly qualify as simultaneously 'competent' wrt the
subjects discussed, and 'rational'.

> You obviously know a lot and I am sure you can
> contribute. Why don't you join us in the discussion.

"Us"? Every single poster here have pointed at at least one
of your flaws, blunders and errors. My list of such approaches
two dozens. Unless you make serious efforts to address such
remarks, no one will 'discuss' with you.

> I told you I have measured the nonlinear phase responce of a magnetic
> dipole antenna using a RF Network analyser and it matches very well with
> the curve in figure 9 of my paper, also in the Sten Paper a NEC simulation
> shows the same results (Figure 3). There is no need to doubt the theory if:
> theory, simmulation, and experiment match.

Your theory is nonsense. Do the derivations of the exact
solutions from scratch (I have told you how elsewhere), and
you will find that there are no "faster-than-c" effects at all.

Again, all this is trivial wave theory 101 material that any
sane, competenet student will figure out in a couple of days
or weeks.

Rune

just in case anyone is interested, WWalker appears to have 9 papers at
arXiv. see http://xxx.lanl.gov/find/all/1/au:+walker_william/0/1/0/all/0/1
..  i am still not sure what the acceptance threshold is for arXiv.
once you're an "endorser", it appears you can post whatever you like
there.

William, don't you think that either sci.physics.research or
sci.physics.foundations are the correct place to discuss your theory
as depicted in your paper http://arxiv.org/abs/physics/0603240 ?  or
the other papers?

also William, i am not trying to be as hard on you as some folks are
here, but we here at comp.dsp know that negative group delay for an
LTI filter does not mean that it violates causality.  if the impulse
response of an LTI filter is causal, there is no way for that filter
to "hurry up" an envelope and cause it at the output to unambiguously
lead the input envelope.  even if that envelope is modulating a
"carrier" at a frequency where the group delay is the most negative.
and we know why it that is true.

if your paper is about modulating an EM wave and purporting that
envelope can "precede" the wavefront propagating in a vacuum at speed
c, we're pretty skeptical.  and i think the guys at s.p.r would be
skeptical also.

r b-j

Eric,

I measured the nearfield magnetic dipole dispersion curve by using a 4 port
24GHz vector network analyser and measuring the transmission coefficient
between two 1.5cm dia. magnetic dipole antennas separted 20cm apart. The
network analyser was 4 port calibrated up to the antennas and the
electrical length of the antennas was measured using the network analyser,
the electrical characteristics of the antenna where calculated and both the
electrical length and electrical characteristics were subtracted from the
result, yielding a phase vs frequency curve that matches very well theory.


The magnetic antennas are simply a solid shield coax cable, bent in a loop
with the outer shields sodered together after the loop, and up to the cable
connectors. The solid shield was severed in the center of the loop making
the outer conductor a shield for the electric field but enabling the
magnetic field to pass. The plane of the loops were parallel during the
measurement. 

The measurement was made indoors but several meters away from metal
objects. Placing metal plates a meter away did not affect the shape of the
curve, only the observed noise of the curve in the farfield, not the
nearfield. When the weather gets better here I will repeat the measurement
outside. This should improve the SNR of the curve in the farfield. 

William



>On 3/30/2010 9:56 AM, WWalker wrote:
>> Rune,
>>
>> You are using insults and ridicule as arguments. Are you afraid to
discuss
>> this topic rationally? You obviously know a lot and I am sure you can
>> contribute. Why don't you join us in the discussion.
>>
>> I told you I have measured the nonlinear phase responce of a magnetic
>> dipole antenna using a RF Network analyser and it matches very well
with
>> the curve in figure 9 of my paper, also in the Sten Paper a NEC
simulation
>> shows the same results (Figure 3). There is no need to doubt the theory
if:
>> theory, simmulation, and experiment match.
>>
>> William
>
>I'm curious as to how you characterized the antenna with an RF NA.  I'd 
>think that would be an extremely difficult thing to do properly. 
>Antenna characterization takes some careful work and usually a special 
>facility.  Even then it's difficult.
>
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 3/31/2010 8:09 AM, WWalker wrote:
> Eric,
>
> I measured the nearfield magnetic dipole dispersion curve by using a 4 port
> 24GHz vector network analyser and measuring the transmission coefficient
> between two 1.5cm dia. magnetic dipole antennas separted 20cm apart. The
> network analyser was 4 port calibrated up to the antennas and the
> electrical length of the antennas was measured using the network analyser,
> the electrical characteristics of the antenna where calculated and both the
> electrical length and electrical characteristics were subtracted from the
> result, yielding a phase vs frequency curve that matches very well theory.

Some sensor must have been used to pick up the magnetic field for the 
NA.   How was that sensor calibrated?   In situations like this it's 
often difficult to separate measurement of the Tx, channel, and Rx 
antennas.  When claiming that the Tx antenna was measured, one has to be 
certain the effects of the channel and the Rx antenna were removed. 
The NA can calibrate the cables out by removing the antennas and 
connecting the cables together, but there is ambiguity between the Tx, 
channel, and Rx antenna, as they are difficult to separate.

How did you do this?


> The magnetic antennas are simply a solid shield coax cable, bent in a loop
> with the outer shields sodered together after the loop, and up to the cable
> connectors. The solid shield was severed in the center of the loop making
> the outer conductor a shield for the electric field but enabling the
> magnetic field to pass. The plane of the loops were parallel during the
> measurement.

> The measurement was made indoors but several meters away from metal
> objects. Placing metal plates a meter away did not affect the shape of the
> curve, only the observed noise of the curve in the farfield, not the
> nearfield. When the weather gets better here I will repeat the measurement
> outside. This should improve the SNR of the curve in the farfield.
>
> William

How long was the NA sweep?  There are ways to calibrate out the channel, 
but they're very difficult and time consuming.  If there were known 
reflectors within range I'd think that'd be problematic for electric 
coupling, but perhaps not with magnetic coupling.

Regardless, again, be careful that you're measuring what you think 
you're measuring.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

WWalker <william.walker@n_o_s_p_a_m.imtek.de> wrote:

 
> I measured the nearfield magnetic dipole dispersion curve by using a 4 port
(snip)

Last night I read chapter 21 of Feynman Lectures on Physics, Vol. 2.

I would recommend that everyone following this discussion read it.

The goal of that chapter is to connect the formula for the
field from a moving charge to Maxwell's equations.   Feynman
claims to almost, but not completely, do that as, at one point,
the math gets too complicated to fit into a book.  He suggests that
advanced students get out a lot of paper to go through that part.

Among others that you can get from that chapter are the potentials
and fields from a charge moving at a constant velocity.  That will
be pretty close to near field for a slowly moving charge, yet
there are some non-obvious results.  

Consider this case:  A charge is moving along the Z-axis with
position (0,0,vt). That is, velocity v going through the origin at t=0.
For an observer along the X-axis, at what time is the potential
(or field) maximum observed?  Two choices:  t=0, or t=x/c
(x being the position of the observer on the X axis.)

As a hint, note that the Lorentz transformation was not derived
to fit special relativity, but to fit Maxwell's equations.  
(Maybe that is why it is named after Lorentz and not Einstein.)

-- glen

On Mar 31, 2:52=A0pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
>
> Consider this case: =A0A charge is moving along the Z-axis with
> position (0,0,vt). That is, velocity v going through the origin at t=3D0.
> For an observer along the X-axis, at what time is the potential
> (or field) maximum observed? =A0Two choices: =A0t=3D0, or t=3Dx/c
> (x being the position of the observer on the X axis.)
>
> As a hint, note that the Lorentz transformation was not derived
> to fit special relativity, but to fit Maxwell's equations. =A0
> (Maybe that is why it is named after Lorentz and not Einstein.)

to simplify things, the thought experiment i prefer is instead of a
single moving charge moving on the Z-axis, what one should consider is
an infinite line of uniform charge (also having a non-zero lineal mass
density) moving along the Z-axis.  actually, it should be two parallel
infinite lines of uniform charge (parallel to the Z-axis) of known
spacing moving together in the Z direction.

for the observer moving along with the two parallel lines of charge,
there is no motion relative to that observer and the problem is simple
electrostatics and, knowing the distance between the two lines, the
repulsive acceleration (sideways) of the two lines can be determined
purely from electrostatics.

now there's a "stationary" observer that watches the two lines of
charge (and the "moving" observer) whiz by him and also notices that,
due to time dilation, the moving observer's clock is ticking more
slowly, so the outward acceleration of the moving lines of charge
appears to be slower than what is observed if they are not moving (as
the first observer sees).

the rate of outward acceleration of the moving lines of charge, when
considering *only* electrostatics together with special relativity is
exactly the same outward acceleration of the same two moving lines of
charge when considering both static and magnetic forces in a classical
context (no relativistic effect).

that thought experiment, first introduced to me by a physics prof (who
now is at Analog Devices) in the 70s, was sufficient to convince me
that the electromagnetic interaction (in the classical context) is
none other than just the sole electrostatic interaction with
relativistic effects applied.

i s'pose the same can be done with lines of mass and the static
Newtonian gravitational interaction, also applying special relativity
and what you'll get out would be consistent with GEM (gravito-electro-
magnetism) where Maxwell's and Lorentz equations have mass (or mass
density) replacing charge (or charge density) and the Coulomb
constant, 1/(4*pi*epsilon_0), is replaced with -G (the minus sign is
because like-signed charges repel while like-signed masses attract).
for some reason (that i don't really get), the gravito-magnetic force
has an extra factor of 2 tossed into it (at least that's what the lit
seems to say).

but, i think either classical EM or GEM can both be sorta understood
by considering the simple Coulomb or Newtonian static model with
relativistic effects.  that's why we know that the magnetic
interaction is really just a consequence of the static interaction and
not a separate fundamental interaction.

r b-j

Jerry,

I am sorry I do not understand your comment here...

> Whatever power is 
>developed in your resistor comes from the field being warped by the 
>receiver, so the equations you use don't apply to the simulation.
>

The Poynting vector just addresses the radiative power, but there is also
nonradiative power in the nearfield which also propagates. This is what I
am discussing in my simulation.

William


>WWalker wrote:
>> Steve,
>> 
>> If I place a grounded resistor (R) on the output of the nearfield
dipole
>> dectector, then the signal voltage (V) will be converted to a current
(I)
>> with the same signal shape as the transmitted signal. The power is      
 
>> I*V = V^2/R and the energy is the the average power. This result is
>> proportional to how I demodulated my signal in my posted simulation,
where
>> I squared the signal and low pass filtered it.  
>> 
>> William
>> 
>>  
>> 
>>>> Steve,
>>>>
>>>> Clearly energy is also propagating faster than light in the dipole
>>> system.
>>>> If the pulsed carrier is propagating faster than light, as shown in
my
>>>> simulaton, then the energy of this signal is just the signal squared
and
>>>> low pass filtered. This is exactly how I detected the signal in my
>>>> simulation. So the detected pulse I showed in my simulation is also
>>>> proportional to the energy.   
>>>>
>>>> William  
>>> Squaring a signal to derive the power is based on assumptions about
phase
>>> relationships. You are *inferring* power propagation. You are not
>>> demonstrating it.
>
>That's a leap needing justification. The E and H fields are in 
>quadrature in the far field; thus the Poynting vector is normal to the 
>wavefront and real power is conveyed. If I recall correctly, E and H are 
>in phase in the near field and "power" is imaginary. Whatever power is 
>developed in your resistor comes from the field being warped by the 
>receiver, so the equations you use don't apply to the simulation.
>
>Jerry
>-- 
>Discovery consists of seeing what everybody has seen, and thinking what
>nobody has thought.    .. Albert Szent-Gyorgi
>�����������������������������������������������������������������������
>

On Mar 31, 4:17=A0pm, robert bristow-johnson <r...@audioimagination.com>
wrote:
> On Mar 31, 2:52=A0pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
>
>
>
> > Consider this case: =A0A charge is moving along the Z-axis with
> > position (0,0,vt). That is, velocity v going through the origin at t=3D=
0.
> > For an observer along the X-axis, at what time is the potential
> > (or field) maximum observed? =A0Two choices: =A0t=3D0, or t=3Dx/c
> > (x being the position of the observer on the X axis.)
>
> > As a hint, note that the Lorentz transformation was not derived
> > to fit special relativity, but to fit Maxwell's equations. =A0
> > (Maybe that is why it is named after Lorentz and not Einstein.)
>
> to simplify things, the thought experiment i prefer is instead of a
> single moving charge moving on the Z-axis, what one should consider is
> an infinite line of uniform charge (also having a non-zero lineal mass
> density) moving along the Z-axis. =A0actually, it should be two parallel
> infinite lines of uniform charge (parallel to the Z-axis) of known
> spacing moving together in the Z direction.
>
> for the observer moving along with the two parallel lines of charge,
> there is no motion relative to that observer and the problem is simple
> electrostatics and, knowing the distance between the two lines, the
> repulsive acceleration (sideways) of the two lines can be determined
> purely from electrostatics.
>
> now there's a "stationary" observer that watches the two lines of
> charge (and the "moving" observer) whiz by him and also notices that,
> due to time dilation, the moving observer's clock is ticking more
> slowly, so the outward acceleration of the moving lines of charge
> appears to be slower than what is observed if they are not moving (as
> the first observer sees).
>
> the rate of outward acceleration of the moving lines of charge, when
> considering *only* electrostatics together with special relativity is
> exactly the same outward acceleration of the same two moving lines of
> charge when considering both static and magnetic forces in a classical
> context (no relativistic effect).
>
> that thought experiment, first introduced to me by a physics prof (who
> now is at Analog Devices) in the 70s, was sufficient to convince me
> that the electromagnetic interaction (in the classical context) is
> none other than just the sole electrostatic interaction with
> relativistic effects applied.
>
> i s'pose the same can be done with lines of mass and the static
> Newtonian gravitational interaction, also applying special relativity
> and what you'll get out would be consistent with GEM (gravito-electro-
> magnetism) where Maxwell's and Lorentz equations have mass (or mass
> density) replacing charge (or charge density) and the Coulomb
> constant, 1/(4*pi*epsilon_0), is replaced with -G (the minus sign is
> because like-signed charges repel while like-signed masses attract).
> for some reason (that i don't really get), the gravito-magnetic force
> has an extra factor of 2 tossed into it (at least that's what the lit
> seems to say).
>
> but, i think either classical EM or GEM can both be sorta understood
> by considering the simple Coulomb or Newtonian static model with
> relativistic effects. =A0that's why we know that the magnetic
> interaction is really just a consequence of the static interaction and
> not a separate fundamental interaction.
>
> r b-j

Hello Robert, et al,

The quick and easy way is via 4-vectors.

Here the scalar electric potential and the magnetic vector potential
form a 4-vector.

It is interesting to note that the fields themselves do not transform
nicely. In fact it is the potentials that affect things and not the
fields. This is well demonstrated by the Aharonov-Boehm effect. Yes
there are cases where you have non zero potentials with zero fields
and can observe the quantum interference being affected by varying the
potential!

But start with a single stationary charge in one frame of reference
(in this frame the potentials are trivial) and then view the charge
from a moving frame and using 4-vector calculus you get the new
potentials. The curl of the magnetic vector potential will give you
the B fields resulting from a single moving charge. A lot of Physics
books will start with the Biot-Savart law and work from there avoiding
the relativity approach. But it makes it much easier to calculate.

Clay

On 3/31/2010 5:46 PM, WWalker wrote:
> Jerry,
>
> I am sorry I do not understand your comment here...
>
>> Whatever power is
>> developed in your resistor comes from the field being warped by the
>> receiver, so the equations you use don't apply to the simulation.

The probe alters the field that it's probing.

> The Poynting vector just addresses the radiative power, but there is also
> nonradiative power in the nearfield which also propagates. This is what I
> am discussing in my simulation.

The power doesn't radiate, but it nevertheless propagates through space. 
Hmmm. I'd like to understand how. I imagine it's akin to the evanescent 
wave just outside a surface of total internal reflection. When another 
interface is put sufficiently close to detect that wave, it is altered.

Jerry
-- 
"It does me no injury for my neighbor to say there are 20 gods, or no
God. It neither picks my pocket nor breaks my leg."
          Thomas Jefferson to the Virginia House of Delegates in 1776.
���������������������������������������������������������������������

Hi Clay,

The propagation distance in my 500MHz carrier simulation is 10cm. But the
distance can be a lot larger for lower carrier frequencies. For example,
if
the carrier frequency (fc) is 1MHz (typical AM radio) then the optimum
propagation distance is 300m (1/6 carrier wavelength) and the envelope
will
arrive 80ns earlier than a light speed (propagating envelope (0.08/fc).
For
lower carrier frequencies, even larger distances and larger light speed
time differences are possible.

In terms of quantum mechanics I think the following might be happening in
this system. If a photon is created a t=0 then as it propagates, because of
the uncertainty principle, the uncertainty of the velocity of the photon is
much larger than c in the nearfield and much less than c in the farfield.
Which means the photon can be much faster than light in the nearfield but
reduces to the speed of light as it propagates into the farfield. Below is
the argument that shows this.

Lets calculate the uncertainty of the velocity of a photon that propagates
one wavelength after it is created: According to the Heisenberg uncertainty
principle, the relation between the uncertainty in Energy (dE) and the
uncertainty in time (dt) is: dE*dt >= h. The time for a photon to cross one
wavelength distance is: dt = lambda/c. Since dE = h*df and df=dv/lambda
then dE*dt=h*dv/c, but dE*dt <= h   therefore:  dv >= c 
For smaller distances the uncertianty will be greater and for larger
distances the uncertainty will be much smaller. 

William


>On Mar 29, 12:18=A0pm, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
>wrote:
>> Jerry,
>>
>> The speed of light is a corner stone in physics and if it is not a
consta=
>nt
>> then many of our theories in physics will be affected. There may be
direc=
>t
>> practical uses as well, but I just guessing: improving accuracy of high
>> speed doppler radar, speeding up communication to spacecraft where time
>> delays are problematic, increasing speed of computers when they are
>> eventually limited by light speed delays etc. As I said, these are only
>> guesses, the main effect would be a change in many of our theories in
>> physics, which would eventually lead to new practical uses and
>> technologies.
>>
>> William
>>
>>
>>
>> >Eric Jacobsen wrote:
>>
>> > =A0 ...
>>
>> >> I think until you can demonstrate something like that the more
likely
>> >> explanation of bandlimited prediction would be expected to prevail.
>>
>> >Even allowing the unlikely possibility that the 6-degree phase advance
>> >*in the near field* represents a real speed increase, and that the
>> >"pulse" in the far field is expected to show no advance at all, What
>> >practical use can this have?
>>
>> >Jerry
>> >--
>> >Discovery consists of seeing what everybody has seen, and thinking
what
>> >nobody has thought. =A0 =A0.. Albert Szent-Gyorgi
>> >- Hide quoted text -
>>
>> - Show quoted text -
>
>Hello William,
>
>I suggest you 1st study the EPR paradox and then look up Bell's
>theorem and see how it applies to Relativity. You are not going to get
>information over any significant distance with superluminal speed.
>Sure there is a probability that a particle will travel faster than
>light for a short distance (say for example across the nucleus of an
>atom about 10^-14 to 10^-15 meters) but when you start to add up all
>of the paths in a Feynman diagram, you will see the probability of it
>happening across a room is not even likely in a time period of the age
>of the Universe.
>
>Clay
>
>

Jerry Avins <jya@ieee.org> wrote:
(snip)
 
> The power doesn't radiate, but it nevertheless propagates through space. 
> Hmmm. I'd like to understand how. I imagine it's akin to the evanescent 
> wave just outside a surface of total internal reflection. When another 
> interface is put sufficiently close to detect that wave, it is altered.

There is an example in Feynman, not long after he introduces the
Poynting vector.  He has a point charge near a bar magnet, with
E cross B circulating but not propagating.  Later on, this turns
out to be necessary to conserve angular momentum.  That is
the angular momentum of the electromagnetic field.

And still no answer to my multiple choice, only two choice, question.  

-- glen

r b-j,

The dicussion here has been very helpful with signal processing and
understanding the information in the signals I use in my simulations. The
topic has been discussed theoretically over dacades without proving or
disproving the superluminal behavior of the the dipole system (i.e. Speed
of Gravity etc). I do not believe theoretical evidence will ever prove it
one way or another. 

My hope is that an experiment might be able to prove or disprove the
superluminal behavior of this system, that is why I am discussing
simulations here to see if a good experimental setup and signal processing
method can be developed.

William


>
>just in case anyone is interested, WWalker appears to have 9 papers at
>arXiv. see
http://xxx.lanl.gov/find/all/1/au:+walker_william/0/1/0/all/0/1
>.  i am still not sure what the acceptance threshold is for arXiv.
>once you're an "endorser", it appears you can post whatever you like
>there.
>
>William, don't you think that either sci.physics.research or
>sci.physics.foundations are the correct place to discuss your theory
>as depicted in your paper http://arxiv.org/abs/physics/0603240 ?  or
>the other papers?
>
>also William, i am not trying to be as hard on you as some folks are
>here, but we here at comp.dsp know that negative group delay for an
>LTI filter does not mean that it violates causality.  if the impulse
>response of an LTI filter is causal, there is no way for that filter
>to "hurry up" an envelope and cause it at the output to unambiguously
>lead the input envelope.  even if that envelope is modulating a
>"carrier" at a frequency where the group delay is the most negative.
>and we know why it that is true.
>
>if your paper is about modulating an EM wave and purporting that
>envelope can "precede" the wavefront propagating in a vacuum at speed
>c, we're pretty skeptical.  and i think the guys at s.p.r would be
>skeptical also.
>
>r b-j
>

On Mar 31, 6:03=A0pm, Clay <c...@claysturner.com> wrote:
> On Mar 31, 4:17=A0pm, robert bristow-johnson <r...@audioimagination.com>
> wrote:
>
> > to simplify things, the thought experiment i prefer is instead of a
> > single moving charge moving on the Z-axis, what one should consider is
> > an infinite line of uniform charge (also having a non-zero lineal mass
> > density) moving along the Z-axis. =A0actually, it should be two paralle=
l
> > infinite lines of uniform charge (parallel to the Z-axis) of known
> > spacing moving together in the Z direction.
>
> > for the observer moving along with the two parallel lines of charge,
> > there is no motion relative to that observer and the problem is simple
> > electrostatics and, knowing the distance between the two lines, the
> > repulsive acceleration (sideways) of the two lines can be determined
> > purely from electrostatics.
>
> > now there's a "stationary" observer that watches the two lines of
> > charge (and the "moving" observer) whiz by him and also notices that,
> > due to time dilation, the moving observer's clock is ticking more
> > slowly, so the outward acceleration of the moving lines of charge
> > appears to be slower than what is observed if they are not moving (as
> > the first observer sees).
>
> > the rate of outward acceleration of the moving lines of charge, when
> > considering *only* electrostatics together with special relativity is
> > exactly the same outward acceleration of the same two moving lines of
> > charge when considering both static and magnetic forces in a classical
> > context (no relativistic effect).
>
> > that thought experiment, first introduced to me by a physics prof (who
> > now is at Analog Devices) in the 70s, was sufficient to convince me
> > that the electromagnetic interaction (in the classical context) is
> > none other than just the sole electrostatic interaction with
> > relativistic effects applied.
>
> > i s'pose the same can be done with lines of mass and the static
> > Newtonian gravitational interaction, also applying special relativity
> > and what you'll get out would be consistent with GEM (gravito-electro-
> > magnetism) where Maxwell's and Lorentz equations have mass (or mass
> > density) replacing charge (or charge density) and the Coulomb
> > constant, 1/(4*pi*epsilon_0), is replaced with -G (the minus sign is
> > because like-signed charges repel while like-signed masses attract).
> > for some reason (that i don't really get), the gravito-magnetic force
> > has an extra factor of 2 tossed into it (at least that's what the lit
> > seems to say).
>
> > but, i think either classical EM or GEM can both be sorta understood
> > by considering the simple Coulomb or Newtonian static model with
> > relativistic effects. =A0that's why we know that the magnetic
> > interaction is really just a consequence of the static interaction and
> > not a separate fundamental interaction.
....
>
> The quick and easy way is via 4-vectors.
>

i might call that "the formal and general and legitimate way".  and i
don't see how you would teach that to college sophomores after they
have first learned about classical EM and later about special
relativity.  engineering/physics/chem majors in their sophomore year
should know how to derive the electrostatic field due to an infinite
line of charge and how that field will act on a little segment (of
given length) of another infinite line of charge (where nothing is
moving).  and they should know how to derive the electromagnetic field
of an identical line of charge that is moving (co-linearly) at some
known velocity and how that magnetic field would act on a short
segment of another similar line of charge that is moving with a know
velocity.  and, once they accept the postulates (i really think that
only one postulate is needed) of special relativity, they should
understand where time dilation comes from and how to apply that to an
observer in motion relative to another observer.

it's a special case.  it does not prove it in the general case, but i
think it can be used to persuade a student who hasn't yet (and may
never) learned about Minkowski spacetime, tensors, and 4-vectors, that
the classical magnetic interaction is nothing more than the
electrostatic interaction with special relativity considered.

and, being an EE into DSP and being a third of a century away from any
formal physics class, it's about where my atrophied neurons regarding
all of this are stuck.  and i never had a physics class where anything
other than the basics of special relativity had been taught (in
"General Physics").  i never had a course in formal SR (with Minkowki
constructs) or in GR (but i think i am okay about the postulates of
both).

r b-j

On 3/31/2010 6:42 PM, WWalker wrote:

   ...

> In terms of quantum mechanics I think the following might be happening in
> this system. If a photon is created a t=0 then as it propagates, because of
> the uncertainty principle, the uncertainty of the velocity of the photon is
> much larger than c in the nearfield and much less than c in the farfield.
> Which means the photon can be much faster than light in the nearfield but
> reduces to the speed of light as it propagates into the farfield. Below is
> the argument that shows this.

So an uncertain velocity is, at least on average, faster? Why?

   ...

Jerry
-- 
"It does me no injury for my neighbor to say there are 20 gods, or no
God. It neither picks my pocket nor breaks my leg."
          Thomas Jefferson to the Virginia House of Delegates in 1776.
���������������������������������������������������������������������

On 3/31/2010 4:09 PM, WWalker wrote:
> r b-j,
>
> The dicussion here has been very helpful with signal processing and
> understanding the information in the signals I use in my simulations. The
> topic has been discussed theoretically over dacades without proving or
> disproving the superluminal behavior of the the dipole system (i.e. Speed
> of Gravity etc). I do not believe theoretical evidence will ever prove it
> one way or another.
>
> My hope is that an experiment might be able to prove or disprove the
> superluminal behavior of this system, that is why I am discussing
> simulations here to see if a good experimental setup and signal processing
> method can be developed.
>
> William

It's going to be difficult to prove or disprove it either way.   I think 
it would have been done by now if it was straightforward, and the 
discussions here seem to indicate how that comes to be.   A physicist 
who doesn't understand signal processing can be (and have been) tripped 
up by misinterpreting the results, as you seem inclined to do.

To use your button-push bomb trigger example again, a step or impulse 
that has been bandlimited spreads out in time.   The impulse (or step, 
but the impulse is easier to follow), which can be defined very 
specifically in time, gets spread out over time by the bandlimiting 
filter.   This can be seen easily in your plots, in Andor's paper, 
anywhere a plot of a bandlimited "impulse" exists.  In high-snr cases 
the temptation is to use the peak of the spread pulse to indicate the 
arrival of the impulse.   At low SNR it may be necessary to integrate 
over the entire pulse length time in order to reliably detect the 
"arrival of the impulse".

Clearly the rising edge of the spread pulse doesn't anticipate the 
arrival of the peak, so from a causality point of view the beginning 
traces of the initial arrival of the leading edge of the pulse may be 
most indicative of the actual arrival time of the earliest portion of 
information associated with the impulse.

Unless, as I mentioned, the SNR is low, in which case one has to wait 
longer to integrate the energy for reliable detection.

So when does the actual, narrow, "impulse" arrive?   It is ambiguous. 
At high SNR it could be argued that detection of initial energy (which 
is why Vladimir suggested you start with zero-input-zero-output, put in 
energy, and see when energy comes out) defines the actual propagation, 
since the system is necessarily causal.

I'm hoping you're beginning to see why a small phase advance that is 
much narrower than the pulse length is NOT reliably indicative of 
accelerated propagation.   It is just a phase advance, and the 
mechanisms by which those can happen are real.   It does not indicate 
propagation faster than c, but people who see the phase advance are 
sorely tempted to continue to point to it and claim either noncausality 
or propagation faster than c.

If you measure from the initial stimulus, i.e., the button push, or the 
arrival of the wideband impulse into the bandlimiting filter, then you 
have a hope of measuring the actual propagation through the system. 
Filter delays can then be observed reliably.   If you just compare the 
relative phases of the signals after bandlimiting and the difference is 
small compared to the length of the impulse response, then it is 
extremely difficult to distinguish phase advance due to dispersive 
effects or negative group delay from accelerated propagation.   Phase 
advance due to bandlimited prediction is the far more likely explanation 
than propagation faster than c, and continuing to point to the phase 
differences as evidence does nothing to resolve the issue.

You could still simulate disconnection of the signal from the Tx antenna 
input by interrupting the signal and see how that affects the output. 
That's a wideband stimulus and it should be much easier to see how fast 
that propagates through the system.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

Clay <clay@claysturner.com> wrote:
(snip)
 
> The quick and easy way is via 4-vectors.
 
> Here the scalar electric potential and the magnetic vector potential
> form a 4-vector.

It isn't that quick and easy, but it does work.  Feynman does
it after he does it the other way.  Or maybe in the middle.
 
> It is interesting to note that the fields themselves do not transform
> nicely. In fact it is the potentials that affect things and not the
> fields. This is well demonstrated by the Aharonov-Boehm effect. Yes
> there are cases where you have non zero potentials with zero fields
> and can observe the quantum interference being affected by varying the
> potential!

Anyway, in Feynman's description there are three terms, one due
to the position of a charge (Coulomb's term except delayed by r/c),
the second is a velocity dependent correction to the first.
The result of the second term is that in the near field the 
electric field vector is radial from (or to) the current position
of the charge in the constant velocity case.  It is just as Jerry
mentioned a long time ago:  in the case of a predictable motion,
nature knows how to fix it.  It might be that is necessary for
special relativity and frame invariance, but it is surprising.

Using that term, in the case of a slowly oscillating charge,
it wouldn't be surprising if the field wasn't what you would expect
from an appropriately delayed Coulomb field.  

The third term is the acceleration term, the only one you see
in the far field, especially for neutral sources.
 
> But start with a single stationary charge in one frame of reference
> (in this frame the potentials are trivial) and then view the charge
> from a moving frame and using 4-vector calculus you get the new
> potentials. The curl of the magnetic vector potential will give you
> the B fields resulting from a single moving charge. A lot of Physics
> books will start with the Biot-Savart law and work from there avoiding
> the relativity approach. But it makes it much easier to calculate.

My college class used the Berkely book, which does get into the
relativistic form pretty fast, but not quite the same as Feynman
does it.  We did have the whole 4-vector explanation, but I don't
think we had homework problems using it.

-- glen

Jerry,

In my last post (argument pasted again below) I presented an analysis which
showed in the nearfield dv>>c in the nearfield and dv<<c in the farfield.
Once the photon is created, it is propagating in one direction away from
the creation point with, lets assume, a possitive velocity. Lets say in the
nearfield dv=10c therefore, the velocity of the photon will range between:
0-10c, with an average of 5c, which is much faster than light. 

"Lets calculate the uncertainty of the velocity of a photon that
propagates
one wavelength after it is created: According to the Heisenberg
uncertainty
principle, the relation between the uncertainty in Energy (dE) and the
uncertainty in time (dt) is: dE*dt >= h. The time for a photon to cross
one
wavelength distance is: dt = lambda/c. Since dE = h*df and df=dv/lambda
then dE*dt=h*dv/c, but dE*dt <= h   therefore:  dv >= c 
For smaller distances the uncertianty will be greater and for larger
distances the uncertainty will be much smaller. 
" 


William


>On 3/31/2010 6:42 PM, WWalker wrote:
>
>   ...
>
>> In terms of quantum mechanics I think the following might be happening
in
>> this system. If a photon is created a t=0 then as it propagates, because
of
>> the uncertainty principle, the uncertainty of the velocity of the photon
is
>> much larger than c in the nearfield and much less than c in the
farfield.
>> Which means the photon can be much faster than light in the nearfield
but
>> reduces to the speed of light as it propagates into the farfield. Below
is
>> the argument that shows this.
>
>So an uncertain velocity is, at least on average, faster? Why?
>
>   ...
>
>Jerry
>-- 
>"It does me no injury for my neighbor to say there are 20 gods, or no
>God. It neither picks my pocket nor breaks my leg."
>          Thomas Jefferson to the Virginia House of Delegates in 1776.
>���������������������������������������������������������������������
>

Jerry,

It is true that in my simulation model I assume the receiving antenna does
not change the field it is detecting. This is possible if the reflections
from the receiving antenna are small and the detected signal is completely
absorbed and not reflected. Since the nearfields decay at 1/r^3 the
reflected signal will be very small by the time they reflect back to the
receiving antenna. This is observed in my network analyser dispersion
measurement test, where the nearfield part of the curve is not affected by
metal plates placed near the antennas. Only the farfield (1/r) fields are
observed to be affected by the metal plates. If the resistor used to detect
the received signal matches the impedance of the antenna, then the signal
will be completely absorbed and not reflected.


William




>On 3/31/2010 5:46 PM, WWalker wrote:
>> Jerry,
>>
>> I am sorry I do not understand your comment here...
>>
>>> Whatever power is
>>> developed in your resistor comes from the field being warped by the
>>> receiver, so the equations you use don't apply to the simulation.
>
>The probe alters the field that it's probing.
>
>> The Poynting vector just addresses the radiative power, but there is
also
>> nonradiative power in the nearfield which also propagates. This is what
I
>> am discussing in my simulation.
>
>The power doesn't radiate, but it nevertheless propagates through space. 
>Hmmm. I'd like to understand how. I imagine it's akin to the evanescent 
>wave just outside a surface of total internal reflection. When another 
>interface is put sufficiently close to detect that wave, it is altered.
>
>Jerry
>-- 
>"It does me no injury for my neighbor to say there are 20 gods, or no
>God. It neither picks my pocket nor breaks my leg."
>          Thomas Jefferson to the Virginia House of Delegates in 1776.
>���������������������������������������������������������������������
>

Eric,

I appreciate this discussion and I do understand the points all of you have
been making very clearly. I teach advanced analog and digital signal
processing, mathematics, as well as RF technique, and EM theory, and I have
been looking at this problem for 20 years. I simply do not agree with some
of the conclusions in this discussion for very logical reasons. 

I think maybe the problem is that we are all having difficulty
understanding what is the information in the simulations being discussed,
where is it located, and how does it propagate. Information is not well
understood and I think it needs to be discussed to see if it can be defined
better, as it applies to these simulations.

As I mentioned before, I agree that if the information is the edge of a
sharp pulse, which is passed through a narrowband nearfield dipole AM
transmission and detection system, then the time delay will be the time
delay of the narrowband filter plus the freespace propagation time of the
pulse edge, which propagates at speed c in both the nearfield and farfield.
The pulse will distort in the nearfield but the edge will be clearly
defined and can be used to trigger a bomb. With this type of setup, the
overall time delay of the pulse edge will clearly be less than a light
speed time delay.

But, if the information signal is directly input, bandlimited, in a
narrowband nearfield dipole AM transmission and detection system, then the
time delay of the bandlimited signal will only be the freespace propagation
delay, which is less than light speed as shown in my simulations. 

For example, if the signal is created by a voltage source that is manualy
slowly adjusted, and if the signal is then mixed with a carrier and sent
though a nearfield dipole system, then the detected envelope will arrive
undistorted earlier than a light propagated signal, as I showed in my
simulations. Each voltage point on the voltage vs time curve of the voltage
source is information about what the voltage was at that time. If that
pattern is reproduced exactly a distance away, then the time delay of each
information voltage point is the propagation time of the information. 


William  


>On 3/31/2010 4:09 PM, WWalker wrote:
>> r b-j,
>>
>> The dicussion here has been very helpful with signal processing and
>> understanding the information in the signals I use in my simulations.
The
>> topic has been discussed theoretically over dacades without proving or
>> disproving the superluminal behavior of the the dipole system (i.e.
Speed
>> of Gravity etc). I do not believe theoretical evidence will ever prove
it
>> one way or another.
>>
>> My hope is that an experiment might be able to prove or disprove the
>> superluminal behavior of this system, that is why I am discussing
>> simulations here to see if a good experimental setup and signal
processing
>> method can be developed.
>>
>> William
>
>It's going to be difficult to prove or disprove it either way.   I think 
>it would have been done by now if it was straightforward, and the 
>discussions here seem to indicate how that comes to be.   A physicist 
>who doesn't understand signal processing can be (and have been) tripped 
>up by misinterpreting the results, as you seem inclined to do.
>
>To use your button-push bomb trigger example again, a step or impulse 
>that has been bandlimited spreads out in time.   The impulse (or step, 
>but the impulse is easier to follow), which can be defined very 
>specifically in time, gets spread out over time by the bandlimiting 
>filter.   This can be seen easily in your plots, in Andor's paper, 
>anywhere a plot of a bandlimited "impulse" exists.  In high-snr cases 
>the temptation is to use the peak of the spread pulse to indicate the 
>arrival of the impulse.   At low SNR it may be necessary to integrate 
>over the entire pulse length time in order to reliably detect the 
>"arrival of the impulse".
>
>Clearly the rising edge of the spread pulse doesn't anticipate the 
>arrival of the peak, so from a causality point of view the beginning 
>traces of the initial arrival of the leading edge of the pulse may be 
>most indicative of the actual arrival time of the earliest portion of 
>information associated with the impulse.
>
>Unless, as I mentioned, the SNR is low, in which case one has to wait 
>longer to integrate the energy for reliable detection.
>
>So when does the actual, narrow, "impulse" arrive?   It is ambiguous. 
>At high SNR it could be argued that detection of initial energy (which 
>is why Vladimir suggested you start with zero-input-zero-output, put in 
>energy, and see when energy comes out) defines the actual propagation, 
>since the system is necessarily causal.
>
>I'm hoping you're beginning to see why a small phase advance that is 
>much narrower than the pulse length is NOT reliably indicative of 
>accelerated propagation.   It is just a phase advance, and the 
>mechanisms by which those can happen are real.   It does not indicate 
>propagation faster than c, but people who see the phase advance are 
>sorely tempted to continue to point to it and claim either noncausality 
>or propagation faster than c.
>
>If you measure from the initial stimulus, i.e., the button push, or the 
>arrival of the wideband impulse into the bandlimiting filter, then you 
>have a hope of measuring the actual propagation through the system. 
>Filter delays can then be observed reliably.   If you just compare the 
>relative phases of the signals after bandlimiting and the difference is 
>small compared to the length of the impulse response, then it is 
>extremely difficult to distinguish phase advance due to dispersive 
>effects or negative group delay from accelerated propagation.   Phase 
>advance due to bandlimited prediction is the far more likely explanation 
>than propagation faster than c, and continuing to point to the phase 
>differences as evidence does nothing to resolve the issue.
>
>You could still simulate disconnection of the signal from the Tx antenna 
>input by interrupting the signal and see how that affects the output. 
>That's a wideband stimulus and it should be much easier to see how fast 
>that propagates through the system.
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

On 4/1/2010 6:22 AM, WWalker wrote:
> Jerry,
>
> In my last post (argument pasted again below) I presented an analysis which
> showed in the nearfield dv>>c in the nearfield and dv<<c in the farfield.
> Once the photon is created, it is propagating in one direction away from
> the creation point with, lets assume, a possitive velocity. Lets say in the
> nearfield dv=10c therefore, the velocity of the photon will range between:
> 0-10c, with an average of 5c, which is much faster than light.
>
> "Lets calculate the uncertainty of the velocity of a photon that
> propagates
> one wavelength after it is created: According to the Heisenberg
> uncertainty
> principle, the relation between the uncertainty in Energy (dE) and the
> uncertainty in time (dt) is: dE*dt>= h. The time for a photon to cross
> one
> wavelength distance is: dt = lambda/c. Since dE = h*df and df=dv/lambda
> then dE*dt=h*dv/c, but dE*dt<= h   therefore:  dv>= c
> For smaller distances the uncertianty will be greater and for larger
> distances the uncertainty will be much smaller.
> "

That argument has a certain amount of plausibility at first hearing, but 
it raises some questions. How far does the photon get from its source 
before the velocity uncertainty becomes very small? What justifies the 
assumption of one wavelength? After all, as the photon's energy varies, 
so does its wavelength.

You wrote dt=lambda/c. shouldn't that be t=lambda/c? When dt/t is much 
greater than unity (you picked 10 in your example) can we still write in 
terms of differentials?

Jerry
-- 
"It does me no injury for my neighbor to say there are 20 gods, or no
God. It neither picks my pocket nor breaks my leg."
          Thomas Jefferson to the Virginia House of Delegates in 1776.

On 4/1/2010 7:10 AM, WWalker wrote:
> Jerry,
>
> It is true that in my simulation model I assume the receiving antenna does
> not change the field it is detecting. This is possible if the reflections
> from the receiving antenna are small and the detected signal is completely
> absorbed and not reflected. Since the nearfields decay at 1/r^3 the
> reflected signal will be very small by the time they reflect back to the
> receiving antenna. This is observed in my network analyser dispersion
> measurement test, where the nearfield part of the curve is not affected by
> metal plates placed near the antennas. Only the farfield (1/r) fields are
> observed to be affected by the metal plates. If the resistor used to detect
> the received signal matches the impedance of the antenna, then the signal
> will be completely absorbed and not reflected.

I may not understand the mechanism, but it seems to me that pulling 
power out of the field that heats the resistor necessarily alters the 
field.

Jerry
-- 
"It does me no injury for my neighbor to say there are 20 gods, or no
God. It neither picks my pocket nor breaks my leg."
          Thomas Jefferson to the Virginia House of Delegates in 1776.

On Apr 1, 5:23=A0am, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
> Clay <c...@claysturner.com> wrote:
>
> (snip)
>
> > The quick and easy way is via 4-vectors.
> > Here the scalar electric potential and the magnetic vector potential
> > form a 4-vector.
>
> It isn't that quick and easy, but it does work. =A0Feynman does
> it after he does it the other way. =A0Or maybe in the middle.
>
> > It is interesting to note that the fields themselves do not transform
> > nicely. In fact it is the potentials that affect things and not the
> > fields. This is well demonstrated by the Aharonov-Boehm effect. Yes
> > there are cases where you have non zero potentials with zero fields
> > and can observe the quantum interference being affected by varying the
> > potential!
>
> Anyway, in Feynman's description there are three terms, one due
> to the position of a charge (Coulomb's term except delayed by r/c),
> the second is a velocity dependent correction to the first.
> The result of the second term is that in the near field the
> electric field vector is radial from (or to) the current position
> of the charge in the constant velocity case. =A0It is just as Jerry
> mentioned a long time ago: =A0in the case of a predictable motion,
> nature knows how to fix it. =A0It might be that is necessary for
> special relativity and frame invariance, but it is surprising.
>
> Using that term, in the case of a slowly oscillating charge,
> it wouldn't be surprising if the field wasn't what you would expect
> from an appropriately delayed Coulomb field. =A0
>
> The third term is the acceleration term, the only one you see
> in the far field, especially for neutral sources.
>
> > But start with a single stationary charge in one frame of reference
> > (in this frame the potentials are trivial) and then view the charge
> > from a moving frame and using 4-vector calculus you get the new
> > potentials. The curl of the magnetic vector potential will give you
> > the B fields resulting from a single moving charge. A lot of Physics
> > books will start with the Biot-Savart law and work from there avoiding
> > the relativity approach. But it makes it much easier to calculate.
>
> My college class used the Berkely book, which does get into the
> relativistic form pretty fast, but not quite the same as Feynman
> does it. =A0We did have the whole 4-vector explanation, but I don't
> think we had homework problems using it.
>
> -- glen

I had this in two different courses. Obviously this comes in E&M where
we used the book by Jackson. Apparently most grad programs in physics
use Jackson. So much so, that some of our foreign students had knock
off copies of the text provided to them by their home country printed
up with many errors not in the official text!  4-vectors were again
demostrated in relativistic astrophysics, which again would be more
appropriate for physics guys than EE guys. And we had homework with 4-
vectors in both courses. I found them to be so useful, that looking
back to other methods seems a bit primative. But that is the advantage
of using a well honed theory. For example deriving the relativistic
doppler shift is simple when one notes that for all observers the
phase of the wave is invariant and therefore the scalar temporal
frequency and the vector "wavenumber" become the transformed quanties.
Even Fresnel's equation for the velocity of light through moving media
becomes trivial to derive once Einstein's velocity addition formula is
applied. Einstein's formula may be easily derived from two
applications of 4-vec transformations.

I don't see many EEs taking this subject this deep (gets kinda far
afield for thier studies) but the salient point there is Maxwell's
eqns are invariant under the Lorentz transformation. Particular
features of the theory may be taken from there by various means.

But to get back to Mr Walker's problem, we see in atomic physics most
transitions involve the dipole approximation which says other
transitions can't happen. But they do, so these are called "forbidden
transitions." Since they occur with lower likelihood the dipole theory
is mostly correct, but like most theories some approximations and
simplications are applied to make the theory tractable. With nearfield
stuff involving antennas one really needs to resort to something like
L & R's theory of retarded potentials. The math quickly gets hairy and
encourages one to approximate and this is where some unreal things
show up in the approximate theory but a thorough and complete
application resolves the quirks.

Clay


p.s. I think Feyman's 3 volume lecture set should be required reading
for all undergraduate physics majors.

On Mar 31, 7:44=A0pm, robert bristow-johnson <r...@audioimagination.com>
wrote:
> On Mar 31, 6:03=A0pm, Clay <c...@claysturner.com> wrote:
>
>
>
>
>
> > On Mar 31, 4:17=A0pm, robert bristow-johnson <r...@audioimagination.com=
>
> > wrote:
>
> > > to simplify things, the thought experiment i prefer is instead of a
> > > single moving charge moving on the Z-axis, what one should consider i=
s
> > > an infinite line of uniform charge (also having a non-zero lineal mas=
s
> > > density) moving along the Z-axis. =A0actually, it should be two paral=
lel
> > > infinite lines of uniform charge (parallel to the Z-axis) of known
> > > spacing moving together in the Z direction.
>
> > > for the observer moving along with the two parallel lines of charge,
> > > there is no motion relative to that observer and the problem is simpl=
e
> > > electrostatics and, knowing the distance between the two lines, the
> > > repulsive acceleration (sideways) of the two lines can be determined
> > > purely from electrostatics.
>
> > > now there's a "stationary" observer that watches the two lines of
> > > charge (and the "moving" observer) whiz by him and also notices that,
> > > due to time dilation, the moving observer's clock is ticking more
> > > slowly, so the outward acceleration of the moving lines of charge
> > > appears to be slower than what is observed if they are not moving (as
> > > the first observer sees).
>
> > > the rate of outward acceleration of the moving lines of charge, when
> > > considering *only* electrostatics together with special relativity is
> > > exactly the same outward acceleration of the same two moving lines of
> > > charge when considering both static and magnetic forces in a classica=
l
> > > context (no relativistic effect).
>
> > > that thought experiment, first introduced to me by a physics prof (wh=
o
> > > now is at Analog Devices) in the 70s, was sufficient to convince me
> > > that the electromagnetic interaction (in the classical context) is
> > > none other than just the sole electrostatic interaction with
> > > relativistic effects applied.
>
> > > i s'pose the same can be done with lines of mass and the static
> > > Newtonian gravitational interaction, also applying special relativity
> > > and what you'll get out would be consistent with GEM (gravito-electro=
-
> > > magnetism) where Maxwell's and Lorentz equations have mass (or mass
> > > density) replacing charge (or charge density) and the Coulomb
> > > constant, 1/(4*pi*epsilon_0), is replaced with -G (the minus sign is
> > > because like-signed charges repel while like-signed masses attract).
> > > for some reason (that i don't really get), the gravito-magnetic force
> > > has an extra factor of 2 tossed into it (at least that's what the lit
> > > seems to say).
>
> > > but, i think either classical EM or GEM can both be sorta understood
> > > by considering the simple Coulomb or Newtonian static model with
> > > relativistic effects. =A0that's why we know that the magnetic
> > > interaction is really just a consequence of the static interaction an=
d
> > > not a separate fundamental interaction.
> ...
>
> > The quick and easy way is via 4-vectors.
>
> i might call that "the formal and general and legitimate way". =A0and i
> don't see how you would teach that to college sophomores after they
> have first learned about classical EM and later about special
> relativity. =A0engineering/physics/chem majors in their sophomore year
> should know how to derive the electrostatic field due to an infinite
> line of charge and how that field will act on a little segment (of
> given length) of another infinite line of charge (where nothing is
> moving). =A0and they should know how to derive the electromagnetic field
> of an identical line of charge that is moving (co-linearly) at some
> known velocity and how that magnetic field would act on a short
> segment of another similar line of charge that is moving with a know
> velocity. =A0and, once they accept the postulates (i really think that
> only one postulate is needed) of special relativity, they should
> understand where time dilation comes from and how to apply that to an
> observer in motion relative to another observer.
>
> it's a special case. =A0it does not prove it in the general case, but i
> think it can be used to persuade a student who hasn't yet (and may
> never) learned about Minkowski spacetime, tensors, and 4-vectors, that
> the classical magnetic interaction is nothing more than the
> electrostatic interaction with special relativity considered.
>
> and, being an EE into DSP and being a third of a century away from any
> formal physics class, it's about where my atrophied neurons regarding
> all of this are stuck. =A0and i never had a physics class where anything
> other than the basics of special relativity had been taught (in
> "General Physics"). =A0i never had a course in formal SR (with Minkowki
> constructs) or in GR (but i think i am okay about the postulates of
> both).
>
> r b-j- Hide quoted text -
>
> - Show quoted text -

I understand everyone comes at this from different backgrounds and
perspectives. Rigorous nearfield stuff with antennas is going to be
mathematically hairy no matter the approach and awaits those in grad
school. Kraus's book on antennas is very good, and it is from a EE's
approach. He also wrote a more general book on E & M. You may have had
one of these, since you went through a EE program. I went 1st through
a mathematics and then a physics program so my viewpoint is different
from that of many others. This is sometimes good and sometimes not so
good ;-) And I agree one of the perils of aging is a slowing of the
brain (mental obtundation)

As an aside, the math for general relativity is so obtuse that
Schwarzschild's solution for the spherically symmetric case (the
simplest one) was worked out about a dozen times by people not
realizing that other worked out solutions were the same solution! We
spent a fair bit of time in the GR course working through the details
of the Schwartzschild case. The Schwarzschild Radius for blackholes
comes from this.

Clay


Clay

On Mar 31, 6:42=A0pm, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
wrote:
> Hi Clay,
>
> The propagation distance in my 500MHz carrier simulation is 10cm. But the
> distance can be a lot larger for lower carrier frequencies. For example,
> if
> the carrier frequency (fc) is 1MHz (typical AM radio) then the optimum
> propagation distance is 300m (1/6 carrier wavelength) and the envelope
> will
> arrive 80ns earlier than a light speed (propagating envelope (0.08/fc).
> For
> lower carrier frequencies, even larger distances and larger light speed
> time differences are possible.
>
> In terms of quantum mechanics I think the following might be happening in
> this system. If a photon is created a t=3D0 then as it propagates, becaus=
e of
> the uncertainty principle, the uncertainty of the velocity of the photon =
is
> much larger than c in the nearfield and much less than c in the farfield.
> Which means the photon can be much faster than light in the nearfield but
> reduces to the speed of light as it propagates into the farfield. Below i=
s
> the argument that shows this.
>
> Lets calculate the uncertainty of the velocity of a photon that propagate=
s
> one wavelength after it is created: According to the Heisenberg uncertain=
ty
> principle, the relation between the uncertainty in Energy (dE) and the
> uncertainty in time (dt) is: dE*dt >=3D h. The time for a photon to cross=
 one
> wavelength distance is: dt =3D lambda/c. Since dE =3D h*df and df=3Ddv/la=
mbda
> then dE*dt=3Dh*dv/c, but dE*dt <=3D h =A0 therefore: =A0dv >=3D c
> For smaller distances the uncertianty will be greater and for larger
> distances the uncertainty will be much smaller.
>
> William
>
>
>
>
>
> >On Mar 29, 12:18=3DA0pm, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de>
> >wrote:
> >> Jerry,
>
> >> The speed of light is a corner stone in physics and if it is not a
> consta=3D
> >nt
> >> then many of our theories in physics will be affected. There may be
> direc=3D
> >t
> >> practical uses as well, but I just guessing: improving accuracy of hig=
h
> >> speed doppler radar, speeding up communication to spacecraft where tim=
e
> >> delays are problematic, increasing speed of computers when they are
> >> eventually limited by light speed delays etc. As I said, these are onl=
y
> >> guesses, the main effect would be a change in many of our theories in
> >> physics, which would eventually lead to new practical uses and
> >> technologies.
>
> >> William
>
> >> >Eric Jacobsen wrote:
>
> >> > =3DA0 ...
>
> >> >> I think until you can demonstrate something like that the more
> likely
> >> >> explanation of bandlimited prediction would be expected to prevail.
>
> >> >Even allowing the unlikely possibility that the 6-degree phase advanc=
e
> >> >*in the near field* represents a real speed increase, and that the
> >> >"pulse" in the far field is expected to show no advance at all, What
> >> >practical use can this have?
>
> >> >Jerry
> >> >--
> >> >Discovery consists of seeing what everybody has seen, and thinking
> what
> >> >nobody has thought. =3DA0 =3DA0.. Albert Szent-Gyorgi
> >> >- Hide quoted text -
>
> >> - Show quoted text -
>
> >Hello William,
>
> >I suggest you 1st study the EPR paradox and then look up Bell's
> >theorem and see how it applies to Relativity. You are not going to get
> >information over any significant distance with superluminal speed.
> >Sure there is a probability that a particle will travel faster than
> >light for a short distance (say for example across the nucleus of an
> >atom about 10^-14 to 10^-15 meters) but when you start to add up all
> >of the paths in a Feynman diagram, you will see the probability of it
> >happening across a room is not even likely in a time period of the age
> >of the Universe.
>
> >Clay- Hide quoted text -
>
> - Show quoted text -

Your photons are also influenced by all of the electrons in the
antenna, so you can't treat it them like they are independent items.
Your transmitting and receiving antennas are highly coupled and the
transmission from your antenna has an extra delay compared to when you
are transmitting to empty free space. When you include this delay, I'm
sure you will see your signal input into the tx's coax cable will not
arrive at the rx's coax cable with superluminal speed.

This reminds of a case two years ago where I met a guy who claimed to
have a machine that created more energy out than he put in. He
"verified" this by 1st measuring the amount of power going into the
the machine. Then he measured the power out by putting a load on it.
Then he concluded he got more power out than he put in. The problem
was he needed to measure the power going it to the maching when it was
loaded. Once this was done, it was clearly observed that the power out
was less than the power in. His investors were not happy! You can
google "Sprain Motor" if you want to know about that particular
machine.

Now think about the loading your receive antenna puts on to the
transmitting antenna. This will cause an extra delay compared to when
there is no loading on the tx antenna.

Clay

On 4/1/2010 5:51 AM, WWalker wrote:
> Eric,
>
> I appreciate this discussion and I do understand the points all of you have
> been making very clearly. I teach advanced analog and digital signal
> processing, mathematics, as well as RF technique, and EM theory, and I have
> been looking at this problem for 20 years. I simply do not agree with some
> of the conclusions in this discussion for very logical reasons.
>
> I think maybe the problem is that we are all having difficulty
> understanding what is the information in the simulations being discussed,
> where is it located, and how does it propagate. Information is not well
> understood and I think it needs to be discussed to see if it can be defined
> better, as it applies to these simulations.

> As I mentioned before, I agree that if the information is the edge of a
> sharp pulse, which is passed through a narrowband nearfield dipole AM
> transmission and detection system, then the time delay will be the time
> delay of the narrowband filter plus the freespace propagation time of the
> pulse edge, which propagates at speed c in both the nearfield and farfield.
> The pulse will distort in the nearfield but the edge will be clearly
> defined and can be used to trigger a bomb. With this type of setup, the
> overall time delay of the pulse edge will clearly be less than a light
> speed time delay.

> But, if the information signal is directly input, bandlimited, in a
> narrowband nearfield dipole AM transmission and detection system, then the
> time delay of the bandlimited signal will only be the freespace propagation
> delay, which is less than light speed as shown in my sim