Naked Science Forum

General Science => General Science => Topic started by: Seany on 06/06/2007 20:51:59

Title: Special substance that slows down the speed of light!
Post by: Seany on 06/06/2007 20:51:59
OK.. My science teacher said that there is a special substance, gas, that can slow down the speed of light..

Is this true? And what benefits, disadvantages can the invention of this do?
Title: Special substance that slows down the speed of light!
Post by: daveshorts on 07/06/2007 00:24:42
Most things slow down the speed of light, glass will slow it down by a factor of 1.5 to 2,  diamond by a factor of about 2.5, this is actually why light refracts see the dissappearing pyrex experiment:

http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/making-pyrex-invisible/

There have been some exotic materials made with much higher refractive indexes at a certain wavelength so light will travel at only a few m/s, but these generally have to be powered with laser light at another wavelength and are very complex.
Title: Special substance that slows down the speed of light!
Post by: _Stefan_ on 07/06/2007 07:15:44
I read about a 'cloud' of gass that could 'freeze' photons for a period of time. Something about using this in quantum computers.
Title: Special substance that slows down the speed of light!
Post by: lightarrow on 08/06/2007 13:48:46
Quote from: _Stefan_ on 07/06/2007 07:15:44
I read about a 'cloud' of gass that could 'freeze' photons for a period of time. Something about using this in quantum computers.
Yes, it's true! It seems possible to "freeze" single photons and store them! Physicists are studying this, with Bose-Einstein Condensates.
Title: Special substance that slows down the speed of light!
Post by: dentstudent on 08/06/2007 14:51:34
Quote from: lightarrow on 08/06/2007 13:48:46
Quote from: _Stefan_ on 07/06/2007 07:15:44
I read about a 'cloud' of gass that could 'freeze' photons for a period of time. Something about using this in quantum computers.
Yes, it's true! It seems possible to "freeze" single photons and store them!


Would that make it a light snack?
Title: Special substance that slows down the speed of light!
Post by: lightarrow on 09/06/2007 19:23:42
Quote from: dentstudent on 08/06/2007 14:51:34
Quote from: lightarrow on 08/06/2007 13:48:46
Quote from: _Stefan_ on 07/06/2007 07:15:44
I read about a 'cloud' of gass that could 'freeze' photons for a period of time. Something about using this in quantum computers.
Yes, it's true! It seems possible to "freeze" single photons and store them!
Would that make it a light snack?
Absolutely!  [;D]
Title: Special substance that slows down the speed of light!
Post by: Seany on 10/06/2007 16:27:14
Heeheee.... I wonder what light particles look like?