Hank Nussbacher wrote:

On Sat, 20 Aug 2005, Fergie (Paul Ferguson) wrote:

I doubt they are exceeding the speed of light. Propogation delay inside fiber is about 2/3 the speed of light so perhaps they have succeeded to increase the speed to 3/4? :-)

-Hank

I have seen experiments with antennas and Oscilloscopes, done by Hewlett and Packard in the 1920s I believe. They have shown the left wing of a dipole antenna knows things in advance that you do to the right wing. The little spike they photographed on their scope did prove it. I have seen a repetition of that experiment at Darmstadt University studying computerscience and having lessons in electricity. I am a hamradio operator. Those guyes are always curious. But sorry I did not comprehend what that experiment was all about. The experiment has shown that really the left wing of the dipole antenna "knows things before you do them". But for you to see them you have to get that information throug a coax cable. That information will reach you the moment you do it. Here we go :) On the other hand I have read again and again about those Lausanne people sending information through tunnels at speeds faster than light and they could proove it. Using normal fiber under normal environment conditions gives things an interesting twist. Now everybody can touch it. Regars, Peter and Karin Dambier

...

Man, I knew I should've gotten in on the ground floor in any effort to speed up light -- someone's going to be rich beyond their wildest dreams. :-)

(Thanks to a post over at Slashdot) the Science Blog reports that:

[snip]

A team of researchers from the Ecole Polytechnique F?d?rale de Lausanne (EPFL) has successfully demonstrated, for the first time, that it is possible to control the speed of light ? both slowing it down and speeding it up ? in an optical fiber, using off-the-shelf instrumentation in normal environmental conditions. Their results, to be published in the August 22 issue of Applied Physics Letters, could have implications that range from optical computing to the fiber-optic telecommunications industry.

[snip]

http://www.scienceblog.com/light.html

- ferg

-- "Fergie", a.k.a. Paul Ferguson Engineering Architecture for the Internet fergdawg@netzero.net or fergdawg@sbcglobal.net ferg's tech blog: http://fergdawg.blogspot.com/

-- Peter and Karin Dambier Public-Root Graeffstrasse 14 D-64646 Heppenheim +49-6252-671788 (Telekom) +49-179-108-3978 (O2 Genion) +49-6252-750308 (VoIP: sipgate.de) +1-360-448-1275 (VoIP: freeworldialup.com) mail: peter@peter-dambier.de http://iason.site.voila.fr http://www.kokoom.com/iason

Okay, guess I should have read the article first, given the title is "Light that travels faster than the speed of light" Steve

Perhaps they are referring to being able to vary the speed while it is below the speed of light. That is, slowing it down to 1/10th the speed of light, and then speeding it up to 1/5th the speed of light.

Steve Brown

I asked about this article to someone who works on optical properties of materials. Here's what he says (I don't pretend to understand everything though): " This is called superluminal propagation, and many groups have shown it in different media; this one is in fiber. However, this does not violate anything apparently because it is only the leading edge of a pulse, and information still cannot go faster than c. I have been trying to understand what Einstein actually said. Apparently he said that "information" cannot be transmitted faster than c. Now light has a phase velocity which exceeds c all the time. The textbooks then say that it is the group velocity that cannot exceed c. But I found out while writing my book that even that is possible near resonances. Then I saw somewhere that "energy velocity" cannot exceed c. Well, I tried deriving that in a general medium and cannot see why it is fundamentally impossible. I asked around, and one of my colleagues says that it is far more subtle than even Einstein may have realized..it is the leading edge of a pulse (or something like that) that can exceed c, but the whole pulse itself cannot. I really don't understand that part, and haven't found any text describing it. (Need to find one)." On 8/22/05, up@3.am <up@3.am> wrote:

No, they were actually over the speed of light for a "portion of the signal":

"They were also able to create extreme conditions in which the light signal travelled faster than 300 million meters a second. And even though this seems to violate all sorts of cherished physical assumptions, Einstein needn't move over relativity isn't called into question, because only a portion of the signal is affected."

On Sun, 21 Aug 2005, Steve Brown wrote:

...

Okay, guess I should have read the article first, given the title is "Light that travels faster than the speed of light"

Steve

...

Perhaps they are referring to being able to vary the speed while it is below the speed of light. That is, slowing it down to 1/10th the speed of light, and then speeding it up to 1/5th the speed of light.

Steve Brown

James Smallacombe PlantageNet, Inc. CEO and Janitor up@3.am http://3.am =========================================================================

On 8/21/05, Peter Dambier <peter@peter-dambier.de> wrote:

I have had a look into one of my microwave books. I have seen in coax cables the speed of lite drop to 90% or 80% depending on the insulator, the dielectric.

I believe this is referred to as "velocity factor". -Steve -- -Steve