psynapse Posted October 17, 2006 Posted October 17, 2006 I remember hearing that in conditions near absolute zero the speed of light slows down so much you could over take a laser beam on a skateboard. Now how can this be if he speed of light is constant and should apear to be traveling at c in all frames of reference. How does the temperature affect c? Is this even a plausible scenerio?
BigMoosie Posted October 17, 2006 Posted October 17, 2006 Light travels slower through materials with different refractive indexes, I can't remember the reason, but I'm pretty sure that temperature has nothing to do with it.
JustStuit Posted October 22, 2006 Posted October 22, 2006 Considering it gets close to absolute zero in space, I would say that is incorrect. Plus it makes no sense
insane_alien Posted October 22, 2006 Posted October 22, 2006 light only appears to slow down when it passes through materials anyway. this is because the photons are being absorbed by the atoms and then re-emitted. between the atoms the photons travel at c. light never slows down its instantaneous velocity, merely its average velocity.
5614 Posted October 22, 2006 Posted October 22, 2006 It does have nothing to do with temperature. i_a's explanation (above) is correct. Back in 2000 scientists stopped light: http://www.newscientist.com/article.ns?id=dn340
Klaynos Posted October 22, 2006 Posted October 22, 2006 It does have nothing to do with temperature. i_a's explanation (above) is correct. Back in 2000 scientists stopped light: http://www.newscientist.com/article.ns?id=dn340 There are temperature dependent refractive indexies though. v (average velocity) = c/n Where n can be a function of temperature.
swansont Posted October 22, 2006 Posted October 22, 2006 Back in 2000 scientists stopped light:http://www.newscientist.com/article.ns?id=dn340 Oh, come now, you know better. They stored information about the light. "Stopped light" is the stuff of tabloids. (as is any mention of Star Trek in an article on quantum teleportation) "in the light stopping experiment, the information is contained in the electromagnetic fields of the light beam and is transferred to the state of the gas atoms."
bascule Posted October 22, 2006 Posted October 22, 2006 The CMBR is slightly above absolute zero yet still plodding on at c
Klaynos Posted October 22, 2006 Posted October 22, 2006 The CMBR is slightly above absolute zero yet still plodding on at c Because it's not being absorbed and reemitted all the damn time the medium it's passing through mostly, n=1
5614 Posted October 23, 2006 Posted October 23, 2006 Oh, come now, you know better.Well, I would say if New Scientist say it then it's good enough, but no, you are right... I do know better, I just worded it a bit very badly.
Ragib Posted October 26, 2006 Posted October 26, 2006 New Scientist isnt actually that good you know, i find real journals like Physics is reliable.
psynapse Posted October 26, 2006 Author Posted October 26, 2006 I don't know why I didn't think of how silly that really sounds when I read it. Thanks for the informative replies. (as usual:-p )
Klaynos Posted October 26, 2006 Posted October 26, 2006 New Scientist isnt actually that good you know, i find real journals like Physics is reliable. Aiming at completly differnt audiances.
Ragib Posted October 27, 2006 Posted October 27, 2006 o i guess, but isnt that what makes the difference? seperates the pros from the amatuers
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