$500 equipment creates FTL signal

Hi, thought you might wanted to see this. A simple set of equipment sent a signal over 120 metre with 4 billion kph! It's based on interference.. read it here:


http://www.newscientist.com/news/news.jsp?id=ns99992796

and for reactions of others:

http://science.slashdot.org/science/02/09/16/1520249.shtml?tid=134

 

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I happen to know, slightly, the former head of Astrophysics at Australia's CSIRO. He was quite happy to tell me that a few experiments, which he described in detail, have transmitted information faster than light (FTL). I don't know, I'm no expert in such things. But he seemed to think the only problems with those experiments were in fiding practical applications and in gaining credibility with the general scientific community.

Sorry, I can't get onto the NS wesbite for some reason.

 

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Excerpts from the article of some importance:

While the peak moves faster than light speed, the total energy of the pulse does not. This means Einstein's relativity is preserved, so do not expect super-fast starships or time machines anytime soon.

Electrons usually travel at about two-thirds of light speed in wires, slowed down as they bump into atoms. Hache says it may be possible to send usable electrical signals to near light speed.

 

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How does a peak travel faster than light, even though the energy of the pulse does not???

Doesn't the peak consist of energy????:bugeye:

Tom

 

it might not, as it is afaik magnetic interference, and apparently interference travels close to instantanuous....

 

Can you do it between earth and Mars? That's where it gets useful.

 

A 50 cent FTL device

... it's called a lightbulb and a piece of paper!

Wave the piece of paper fast enough in front of the lightbulb, and the shadow projected on the wall will move faster than light...

Bye!

Crisp

 

that could work in theory... however, at the speed at which you could wave the paper, i think the wall would have to be pretty far away, far enough that you would need better than a 50 cent light bulb

 

Faster than the speed of light... with Fourier series

Much of the following is synthesized from "Optics" 4-th edition, by Eugene Hecht, pp. 299-300, "Group Velocities." An experiment a little more elaborate, but similar to, the $500 experiment was conducted a few years ago:

The setup had a diode laser firing a very long (relatively) 3.7 us Gaussian pulse towards a Cesium gas filled cell. An essentially identical pulse appeared at the far side of the cell even before the peak of the incoming pulse reached the entrance. The measured lead time was 62 ns, the equivalent of the exiting pulse geting about 20 m ahead of the entering pulse, ~310 times the speed of light in vacuum.

The solution to the apparent contradiction of Relativity (information travelling faster than the speed of light) is Fourier Series... The Gaussian packet can be considered as a sum of an infinite number of sinusoids (with different frequencies) that happens to add up towards the middle of a certain range and cancel out at its tails (this corresponds physically to photon waves with different energies). However, the same essential 'information' (coefficients of the 'sinusoids' at the different frequencies) is contained everywhere. When the leading wing went into the cell, the cesium atoms took up and re-emitted the sine waves, shifting their relative phases (in a frequency-dependent way). Basically, a clone of the original wave packet is created, appearing at the far end of the cell, as if the pulse had travelled faster than the speed of light. (The peak of the original pulse is absorbed into the cesium cell).

 

was it the author who performed the experiment? could you give a name or lab where this took place?

 

Doing a Google search, it appears that a team at the NEC Research Institute in New Jersey published their findings in Nature in October of 2000 (meaning the experiment was probably conducted sometime in the summer). Here's a link at Photonics (a leading photonics, i.e. lasers, light communications, etc.)

http://www.photonics.com/Spectra/Tech/Oct00/techFaster.html

Here's the actual paper itself, if you're so inclined:

http://www.neci.nec.com/homepages/lwan/paper/paper49.pdf

The search terms I used were:
cesium cell group velocity gaussian

Jay

 

whats up with this link?

http://www.photonics.com/Spectra/Tech/Oct00/techFaster.html


it comes up

http:///

weird oh well i hate tinkering with computers

 

link works fine for me.

but then again, i love computers. computers can tell when the user doesn t know anything, or hates computers, and they behave worse for those people. computers know who is at the reins.

(-:

 

Oops...

Yeah, I'm still getting the hang of all of this...

What I meant to say was that there was a summary in Photonics (a leading photonics e.g. lasers, LEDs, light communications, etc. publication) at:

http://www.photonics.com/Spectra/Tech/Oct00/techFaster.html

Jay

 

okay, I didn't download the paper because i'm seirously trying to avoid installing adobe acrobat.


according to the artical,

exactly how is this negative time? So it took 1/310 the time the vacuum transit time. How is that negative? The implications seems that the pulse arrived before it was transmitted, or are they putting a limiting speed of c to come up with this statement?
(the pulse traveled at c yet arrived in 1/310 of the time)

does this mean a A near-Gaussian distribution? I'm not too familiar with the term and how it can be applied.

I have another question about the speed of light with respect to frame of reference, but i decided its too complicated and I'll have to bring that up in a relativity thread ( which I've been avoiding because they are so time consuming)

 

time to bash another article.

as for the first post in this thread the article says

now some one please tell me the correct answer. I seem to remember from another thread here that the speed of electrons is actually more in the order of mm/min. Its the signal or the pressure in the analogous water/electricity comparison. I read half through the comments without seeing mention of this before I became too bored (their humor is way too dry for me over there). comments anyone?

 

lethe:

did you click my link? it worked fine for me also. the funny thing is i straight copy and pasted it from the Trekker's. does anyone else get that from Trekker's link? (http:///)

i'm confused

 

Conduction electrons in a metal can be considered an ideal electron gas for a first approximation. In such a case, the electrons on average have thermal energy ~ 3/2 * kT, which means that they move in random directions at about 116,000 m/s, or 0.0003 c. A better approximation can be made by employing the Fermi energy of the metal under study, but that might be outside the scope of what I'm willing to type here. In general, individual electrons in a wire tend to have velocities on the order of a million m/s.

The electrons drift toward the positive end of the wire at about v_d = J / ne, where v_d is the drift velocity, J is the current density (A / m^2), n is the electron density, and e is the electronic charge. For a 1 mm diameter round-cross-section copper wire, the drift velocity is about 4.3 mm/s.

The speed that the field itself propagates depends more on the surrounding medium than on the wire itself. For a wire surrounded by vacuum (or air, which has nearly the same dielectric constant), the field propagates at essentially light speed. For a trace on a printed circuit board, the field propagates at something on the order of six inches per nanosecond, or about 0.5 c. Various PCB standards exist with well defined propagation speeds.

- Warren

 

chroot: good post!