This is a touchy topic for a lot of people, so I hesitated for a few days to post it. I'll keep the quoted text to a minimum, so you'll need to do extra clicking to go outside this blog if you want to read it all. I'm sorry for being such a windbag on this topic. There's a fun thought experiment at the end for any of you who make it that far.
A team of French researchers managed today both to
speed up and slow down light. Normally light travels about 300 million meters per second, but the team was able to slow it down by a factor of 3.6, or make it travel slightly faster. The researchers say slowing down light will help signal processing, allowing us to vastly speed up telecommunications.
Source:
Technocrat
So what's the big deal? As one commenter said regarding the faster than light claim, "I call bullshit." For the sake of the average person's
understanding of the matter, that comment is right on the money. Can we travel faster than light (without using some so far unattained "tricks" used in common science fiction stories)? No. Specifically, information cannot travel faster than light. Arguably, photons themselves might be convinced to go faster than light... but not convey any information.
Keep in mind that the claim of slowing light down is not a big deal. The "speed of light" commonly references is that of light traveling through a vacuum. Light goes slower through any other matter, such as water, glass, air, etc.

Cerenkov radiation is an interesting example of charged particles going
faster than the speed of light in water (0.75 c). The result is a blue glow around the submerged reactor. The photo to the right is an image of the nuclear reactor at PSU. At night on campus you can pick NucE students out of a crowd by their faint blue glow. ... just kidding.
So how did they get a result that showed faster than light (c) velocities? I'm not fully qualified to explain it, so I'll give a few references. The key to it is the difference between light's group velocity and
phase velocity. Commenters (1,
2)
to the
Slashdot article give a little insight into the difference. This
page has a really good animated graphic to help you understand the illusion of faster-than-light information transfer.
This Science Blog article
on this gives a good explanation of why changing light's velocity is important to the future of communications. This
MSNBC article covers a similar story back in 2000.
Continue reading "Faster than light" »