How to get envelope from AM signal without phase shift

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
&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;

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
>&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;&#65533;
>

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