FTL data cable test

[Beleth]

Okay, I'm stumped.

Mr. Randi gives, as an example of a bad submission to the Challenge, a poorly-formatted but otherwise perfectly reasonable description of a claim and a test.

To me, it looks like a very straightforward introductory letter. He says what he believes his cable can do, he proposes a very objective-sounding test, and he says that he is willing to proceed further. It's all very good-faith sounding.

What's Mr. Randi's problem with it? He does not go into detail in the Commentary.

[Kess]

I wondered why Randi dismissed this as a "bad" application too. The applicant's English may leave a bit to be desired but, as you say, their claim is straightforward and should be easy to test.

I'm convinced the FTL cable is a scam, and the experiment the manufacturer proposes to demonstrate it's apparent FTL operation is fundamentally flawed and should be easily debunked by someone with the proper technical expertise. However, it's not clear why Randi seems to have dismissed the application out of hand.

[Beleth]

I'd love to see your technical reason why this doesn't work, Kess (the one you mention in the other thread). I've got the relativity part down pretty well but I'm at a loss with the electromagnetism part. Always have been.

[Agammamon]

The real question is, even if proved true, how a FTL data transmission is proof of the paranormal. Paranormal covers psi, ghosts, and suchlike. FTL transmission would seem to be merely a physics breakthrough (albeit an important one) and more appropriately submitted to Nature.

[Kess]

Originally posted by Beleth
I'd love to see your technical reason why this doesn't work, Kess (the one you mention in the other thread). I've got the relativity part down pretty well but I'm at a loss with the electromagnetism part. Always have been.
I'm not sure if I can explain it in a few words, but here goes. The experiment I'm analysing is the one towards the bottom of http://www.ultra-faster-than-light.com/hwodoesitwork.htm, (under the "Part B" heading), where the author injects a 1MHz sinewave into a 2m length of cable.

Initially, a 50 Ohm resistor is attached to the end of the cable and he reports seeing a 10ns delay. Signal propagation speed in a cable is typically a little less than the free-space speed of light, so this figure is consistent with 2m of cable.

The resistor is then removed and the observed delay drops to <1ns. He concludes that some magical FTL mode of operation has been obtained and the speed of light has been vastly exceeded.

What's really happening? The resistor, when fitted, "matches" the cable impedance and absorbs the signal energy reaching the end of the cable; this means that the signal injected into one end of the cable is faithfully reproduced at the other, without reflections or distortions. When the resistor is removed, however, the signal reaching the end of the cable is no longer absorbed and reflects back up the cable to the start. Therefore at the start of the cable you will get the injected sinewave plus a reflected sinewave delayed by a total of 20ns. The oscilloscope will simply display the sum of these two signals - which is a new sinewave shifted midway between the other two - in other words with an apparent delay of 10ns. This looks just like the 10ns delayed sinewave at the other end of the cable... so we have the illusion of FTL signal propagation.

I'm an electronic engineer and simulated the above setup and proved that the "trick" does work - BUT only when a periodic sinewave signal is used, as the reflected waveform then interferes with the injected signal in just the right way to give the required effect. If his cable were truly capable of FTL speeds then he should prove it be injecting a single event - such as a pulse - into the cable. If the pulse arrives at the other end in less than 10ns, then he might have something worth boasting about.

So it's all done with mirrors - or at least with reflections!

Hope that's clear enough.

Kess

[Kess]

Originally posted by Beleth
I'd love to see your technical reason why this doesn't work, Kess (the one you mention in the other thread). I've got the relativity part down pretty well but I'm at a loss with the electromagnetism part. Always have been.
I'm not sure if I can explain it in a few words, but here goes. The experiment I'm analysing is the one towards the bottom of http://www.ultra-faster-than-light.com/hwodoesitwork.htm, (under the "Part B" heading), where the author injects a 1MHz sinewave into a 2m length of cable.

Initially, a 50 Ohm resistor is attached to the end of the cable and he reports seeing a 10ns delay. Signal propagation speed in a cable is typically a little less than the free-space speed of light, so this figure is consistent with 2m of cable.

The resistor is then removed and the observed delay drops to <1ns. He concludes that some magical FTL mode of operation has been obtained and the speed of light has been vastly exceeded.

What's really happening? The resistor "matches" the cable impedance and absorbs the signal energy reaching the end of the cable; this is the optimal way of connecting up a length of cable (or transmission line, to be precise) and means that the signal injected into one end is faithfully reproduced at the other, without reflections or distortions. When the terminating resistor is removed, however, the signal reaching the end of the cable is no longer absorbed and reflects back up the cable to the start. Therefore at the start of the cable you will then get the injected sinewave plus a reflected sinewave delayed by a total of 20ns. The oscilloscope will simply display the sum of these two signals - which is a new sinewave shifted midway between the other two - in other words with an apparent delay of 10ns. This looks just like the 10ns delayed sinewave at the other end of the cable... so we have the illusion of FTL signal propagation.

I'm an electronic engineer and simulated the above setup and proved that the "trick" does work - BUT only when a periodic sinewave signal is used, as the reflected waveform then interferes with the injected signal in just the right way to give the required effect. If his cable were truly capable of FTL speeds then he should prove it be injecting a single event - such as a pulse - into the cable. If the pulse arrives at the other end in less than 10ns, then he might have something worth boasting about.

So it's all done with mirrors - or at least with reflections!

Hope that's clear enough.

Kess

[roger]

Originally posted by Kess
Hope that's clear enough.
Very clear. Thanks!

[MathewOrman]

Originally posted by Kess

I'm not sure if I can explain it in a few words, but here goes. The experiment I'm analysing is the one towards the bottom of http://www.ultra-faster-than-light.com/hwodoesitwork.htm, (under the "Part B" heading), where the author injects a 1MHz sinewave into a 2m length of cable.

Initially, a 50 Ohm resistor is attached to the end of the cable and he reports seeing a 10ns delay. Signal propagation speed in a cable is typically a little less than the free-space speed of light, so this figure is consistent with 2m of cable.

The resistor is then removed and the observed delay drops to <1ns. He concludes that some magical FTL mode of operation has been obtained and the speed of light has been vastly exceeded.

What's really happening? The resistor, when fitted, "matches" the cable impedance and absorbs the signal energy reaching the end of the cable; this means that the signal injected into one end of the cable is faithfully reproduced at the other, without reflections or distortions. When the resistor is removed, however, the signal reaching the end of the cable is no longer absorbed and reflects back up the cable to the start. Therefore at the start of the cable you will get the injected sinewave plus a reflected sinewave delayed by a total of 20ns. The oscilloscope will simply display the sum of these two signals - which is a new sinewave shifted midway between the other two - in other words with an apparent delay of 10ns. This looks just like the 10ns delayed sinewave at the other end of the cable... so we have the illusion of FTL signal propagation.

I'm an electronic engineer and simulated the above setup and proved that the "trick" does work - BUT only when a periodic sinewave signal is used, as the reflected waveform then interferes with the injected signal in just the right way to give the required effect. If his cable were truly capable of FTL speeds then he should prove it be injecting a single event - such as a pulse - into the cable. If the pulse arrives at the other end in less than 10ns, then he might have something worth boasting about.

So it's all done with mirrors - or at least with reflections!

Hope that's clear enough.

Kess

See the example of single pulse propagation at:
http://www.ultra-faster-than-light.com/ftlspeed.htm


Sincerely,

Mathew Orman


www.ultra-faster-than-light.com
www.radio-faster-than-light.com

[Kess]

Your new experiment is an improvement - using a pulse input - but it still seems flawed. I've repeated your simulation and got the same results as you, but...

The effect you're seeing remains a product of reflections along the unterminated cable. This can give odd effects. Look carefully at the bottom left corner of your waveform graph ( http://www.ultra-faster-than-light.com/LTspice_waveforms.pdf ) - the voltage at the end of the cable in FTL mode (green curve) really doesn't start to rise until 5ns after the input signal rise (red curve), so it isn't FTL at all. After this the signal at the end of the cable seems to catch up with the input signal but this is just a byproduct of the slow rise time, lack of termination and the signal reflection it causes.

It seems suspicious that you're using a low-pass filter that slows down the pulse rise/fall times so they are longer than the 5ns cable propagation delay - this combination just happens to create the illusion of FTL signal propagation. (It's also worth pointing out that any speed benefit due to FTL, if it existed, is probably more than cancelled out by the delay in the filter!) If you get rid of the filter and use zero pulse rise/fall times, or increase the transmission line delay, the illusion breaks down and you can see the speed of light isn't broken. Try it...

[Kess]

Oh, one other thing. Since your simulations clearly prove (apparently) that the FTL effect can be achieved with cheap old RG58 cable, by simply eliminating the terminating resistor, what's special about the expensive FTL cable you're trying to sell?

[MathewOrman]

Originally posted by Kess
Oh, one other thing. Since your simulations clearly prove (apparently) that the FTL effect can be achieved with cheap old RG58 cable, by simply eliminating the terminating resistor, what's special about the expensive FTL cable you're trying to sell?

So many false assumptions!

5.2 ns start point of the output is due to lack of proper
LTspice transmission line models.
That model assumes infinite length.
To remove that you can create distributed model
with ten RLC lump circuits.

To find the answer to you other question
check my new thread at :
http://www.randi.org/vbulletin/showthread.php?s=&threadid=25834&perpage=40&pagenumber=1

Sincerely,

Mathew Orman


www.ultra-faster-than-light.com
www.radio-faster-than-light.com

[Kess]

Originally posted by MathewOrman
[B]
So many false assumptions!
5.2 ns start point of the output is due to lack of proper
LTspice transmission line models.

If you believe the Spice model is fundamentally flawed then perhaps you should not use it to back up your claims - are you saying that the signal relationship predicted by the simulator differs from what you see with actual measurements?

[MathewOrman]

Originally posted by Kess

If you believe the Spice model is fundamentally flawed then perhaps you should not use it to back up your claims - are you saying that the signal relationship predicted by the simulator differs from what you see with actual measurements?

Yes.

There is a different mathematical mode for
what transmission line theory calls "Electrically short open-ended transmission line"
You can find out about it searching with keywords like:
+"Electrically short"+"transmission line"

Sincerely,

Mathew Orman


www.ultra-faster-than-light.com
www.radio-faster-than-light.com

[CurtC]

Oh, bullsh*t. There is *not* a different "mathmatical mode" for short transmission lines. It's just that when they're short, you can usually get away with making some simplifying assumptions. If you say otherwise, you need to say exactly what you mean, instead of telling us to Google it.

Care to give us a Spice model of your "compensating network" and "high impedance buffer"? Then chain them together in Spice and show how it predicts FTL?

[Kess]

Originally posted by MathewOrman

There is a different mathematical mode for
what transmission line theory calls "Electrically short open-ended transmission line"

OK, I've done the search and verified that a line is considered electrically short if its length is less than a quarter of the signal wavelength. However, as CurtC says the mathematics and laws of physics don't suddenly change; the "short" and "long" distinction is just an engineering rule-of-thumb that allows the line's behaviour to be simplified (with a "short" line you can basically ignore the line impedance and assume input impedance = terminating load).

Isn't the problem with a short line that, because propagation effects are much quicker than the periods of the conducted signals, reflections due to the open-circuit end can create all sorts of strange illusions. If you're convinced that FTL is really happening, can you construct an experiment that can distinguish between true FTL signal propagation and the very similar pattern that, as the simulator shows, can be explained by reflections?

[MathewOrman]

Originally posted by Kess

OK, I've done the search and verified that a line is considered electrically short if its length is less than a quarter of the signal wavelength. However, as CurtC says the mathematics and laws of physics don't suddenly change; the "short" and "long" distinction is just an engineering rule-of-thumb that allows the line's behaviour to be simplified (with a "short" line you can basically ignore the line impedance and assume input impedance = terminating load).

Isn't the problem with a short line that, because propagation effects are much quicker than the periods of the conducted signals, reflections due to the open-circuit end can create all sorts of strange illusions. If you're convinced that FTL is really happening, can you construct an experiment that can distinguish between true FTL signal propagation and the very similar pattern that, as the simulator shows, can be explained by reflections?

I can do that but only with continuous sinusoidal waveform.
Construct a Tline with 50ns delay and drive it with 20MHz sine waveform.
You will get zero phase shift so it looks like instantaneous.

Sincerely,

Mathew Orman


www.ultra-faster-than-light.com
www.radio-faster-than-light.com

[gnome]

Originally posted by Agammamon
The real question is, even if proved true, how a FTL data transmission is proof of the paranormal. Paranormal covers psi, ghosts, and suchlike. FTL transmission would seem to be merely a physics breakthrough (albeit an important one) and more appropriately submitted to Nature.

If they were to accept this as a paranormal claim, I think the rationale would be that the claim is so out of accord with known science that it counts as paranormal, even if it is performed with technological methods.

[ceptimus]

Haven't particles that are quantum entangled, been shown (by regular science) to "communicate" FTL?

I put the word 'communicate' in quotes above, as there is no method (even in theory) of using this quantum entanglement to pass information through a data channel FTL, but nethertheless, the two particles can be shown to be somehow connected to each other, and this 'connection' works at infinite speed.

[Kess]

Originally posted by ceptimus
Haven't particles that are quantum entangled, been shown (by regular science) to "communicate" FTL?
You made me curious so I did some digging around. There's a description of an impressive experiment at http://www.pacificsites.com/~cmorford/Her_Sci/E_U/Faster_Than_Light.htm. I found a copy of what looks like the resulting scientific paper is at http://www.arxiv.org/PS_cache/quant-ph/pdf/0007/0007008.pdf. Perhaps someone with more physics expertise can plough through it, but the bottom line seems to be that the "speed of quantum information" was measured at 15,000 x the speed of light!

[Blondin]

I knew I'd heard about this someplace else. Follow this link:

Quantum Entanglement (http://radio.cbc.ca/programs/quirks/archives/02-03/dec14.html)

to hear a blurb about this subject on CBC Radio's Quirks & Quarks from December of last year.

[baggie]

Originally posted by ceptimus
Haven't particles that are quantum entangled, been shown (by regular science) to "communicate" FTL?

I put the word 'communicate' in quotes above, as there is no method (even in theory) of using this quantum entanglement to pass information through a data channel FTL, but nethertheless, the two particles can be shown to be somehow connected to each other, and this 'connection' works at infinite speed.

it shows either FTL communication or non-local reality. Most scientists plump for the later, but intuitively we feel the former corresponds closer to our day t day reality even if wrong (e.g how can something happening on a distant universe be affecting us, astrology excepted).

[Pakaran]

Originally posted by Agammamon
The real question is, even if proved true, how a FTL data transmission is proof of the paranormal. Paranormal covers psi, ghosts, and suchlike. FTL transmission would seem to be merely a physics breakthrough (albeit an important one) and more appropriately submitted to Nature.

That's a good point. In 1960, having a computer capable of operating at 500 megahertz essentially forever would be an extraordinary claim. Now, such computers can't even be bought new - but they're no more "paranormal" now than they were then.