Posted on 07/25/2006 10:13:18 AM PDT by Ben Mugged
Physicist Costas Soukoulis and his research group at the U.S. Department of Energy's Ames Laboratory on the Iowa State University campus are having the time of their lives making light travel backwards at negative speeds that appear faster than the speed of light.
~snip~ This backward-bending characteristic of metamaterials allows enhanced resolution in optical lenses, which could potentially lead to the development of a flat superlens with the power to see inside a human cell and diagnose disease in a baby still in the womb.
~snip~ In addition, Soukoulis and his University of Karlsruhe colleagues have also shown that both the velocity of the individual wavelengths, called phase velocity, and the velocity of the wave packets, called group velocity, are both negative, which Soukoulis said accounts for the ability of negatively refracted light to seemingly defy Einstein's theory of relativity and move backwards faster than the speed of light.
Elaborating, Soukoulis said, "When we have a metamaterial with a negative index of refraction at 1.5 micrometers that can disperse, or separate a wave into spectral components with different wavelengths, we can tune our lasers to play a lot of games with light. We can have a wavepacket hit a slab of negative index material, appear on the right-hand side of the material and begin to flow backward before the original pulse enters the negative index medium."
Continuing, he explained that the pulse flowing backward also releases a forward pulse out the end of the medium, a situation that causes the pulse entering the front of the material appear to move out the back almost instantly.
"In this way, one can argue that that the wave packet travels with velocities much higher than the velocities of light," said Soukoulis.
(Excerpt) Read more at spacedaily.com ...
Read the source article, this extract does not do it justice......
Ping.
bookmark
All this means is that the shape of the wave changed. The velocity of energy propagaiton in any material is always less than c. Here they are simply talking about phase velocities which are related to wave shape, not energy propagation.
Allow me to reply to this.
...there.
Goofy, but hey ... I'll ping the list.
|
Give me a practical application that will help the common man.......in the next 7 years.
Read the article.
Very succinct. I concur.
My original question stands.
It's a little misleading to confuse the phase velocity with the velocity of light, though it's hard to explain the difference to someone who has not been formally trained in physics.
HA! I replied to this YESTERDAY!.........
Of what importance is your original question? What is so special about seven years?
That's nothing. I had some stocks recently that moved backwards faster than the speed of light.
The phase velocity of a wave is the rate at which the phase of the wave propagates in space. This is the velocity at which the phase of any one frequency component of the wave will propagate. You could pick one particular phase of the wave (for example the crest) and it would appear to travel at the phase velocity. The phase velocity is given in terms of the wave's frequency and wave vector k by
v_\mathrm{p} = \frac{\omega}{k}
Note that the phase velocity is not necessarily the same as the group velocity of the wave, which is the rate that changes in amplitude (known as the envelope of the wave) will propagate.
The phase velocity of electromagnetic radiation may under certain circumstances exceed the speed of light in a vacuum, but this does not indicate any superluminal information or energy
Because that's about the amount of time, IMO, that the comman man will wait for a revolutionary development, in even a trial environment.
After that it's forgotten about and loses funding.
(Pointless tangent)
Reminds me of...
Prosecutor: "Did you check for breathing?"
Defendant: "No."
P: "Did you check his pulse?"
D: "No."
P: "Did you, in fact, do ANYTHING to confirm whether the victim was, in fact, deceased?"
D: "No."
P: "Then how could you know he was, in fact, deceased?"
D: "His brain was sitting in a jar on my desk."
Yeah, I understand that, but what kind of an analogy can you come up with that the average guy would understand?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.