Stunning Revolution in Physics or dumb Newspaper?

AI Thread Summary
Recent discussions highlight claims that physicists have managed to both slow down and speed up the speed of light, likely referring to light's behavior in various media rather than in a vacuum. The conversation suggests that the reported speed increase may involve changes in phase velocity, which does not violate relativity principles as it does not allow for the transmission of information faster than light. Some participants express skepticism about the implications of these findings, emphasizing that any significant changes to the fundamental laws of physics are unlikely. The consensus is that while the experiments are intriguing, they do not challenge established scientific theories. Overall, the topic revolves around the nuances of light speed in different contexts and the implications of recent experimental results.
Lyuokdea
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Ok, I was looking through technocrat and I saw a link to this article which claims, that physicists have not only succeeding in slowing down, but also in speeding up the speed of light. I assume it is actually talking about the speed of light in the medium or something, but the article doesn't seem to claim that, does anybody know what was actually accomplished, I doubt the laws of physics were suddenly overturned with this little fanfare.

http://www.eurekalert.org/pub_releases/2005-08/epfd-ltt081905.php

~Lyuokdea
 
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Being in an optical fibre my guess would be "in a medium"
 
Lyuokdea said:
Ok, I was looking through technocrat and I saw a link to this article which claims, that physicists have not only succeeding in slowing down, but also in speeding up the speed of light. I assume it is actually talking about the speed of light in the medium or something, but the article doesn't seem to claim that, does anybody know what was actually accomplished, I doubt the laws of physics were suddenly overturned with this little fanfare.

but they've also accomplished the considerable feat of speeding it up – making light go faster than the speed of light.

Sounds like its in a medium or the world would have gone insane. I suppose we need to determine how important is it in context then we can figure out what they meant by speeding up light. I guess if all experiments so far have simply been to slow down light, it would be very exciting if they were able to speed it back up again after its been slown down.

And by taking 10 more seconds to continue reading, I stumbled upon this.

They were also able to create extreme conditions in which the light signal traveled 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.

What does that mean?
 
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Its probably a fibre that changes properties upon a given signal, such as electric current. This change in properties can either speed up or slow doen light. As for the claims that they can make it go faster than the speed of light in a vacum, (if they do claim that at all) I don't believe it.

Regards,

Nenad
 
Looking around I found a more in depth article that seems to argue that it has to do with changing the phase velocities for the different frequencies of light moving through the cable. I think they are talking about this illusion coming from quantum mechanical phenomena, but does it actually allow particles to move faster than the speed of light?

http://www.livescience.com/technology/050819_fastlight.html

~Lyuokdea
 
Yes, it is phase velocity they are talking about.
 
Tide is correct, they are talking about phase velocity [which is irrelevant]. Relativity is not imperiled until useful information is communicated at superluminal velocities.
 

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