On Sun, 11 Jan 2009 21:52:11 -0800, John Smith
wrote:

Cecil Moore wrote:

...
If they didn't say zero *rest* mass, they should have.
...

Where can I buy a bottle of "photons at rest?"; I like to buy a bottle
just to make sure!

See "slow light" at:
http://en.wikipedia.org/wiki/Slow_light
Not totally at rest, but really slow.

Slow light window glass would be nifty. It would load up with photons
when the sun is shining, and unload them later inside in the evening,
when it's dark. You would also see through the window what was seen
perhaps a few hours before as a delayed action movie.

Actually, how can a photon possibly rest?; well, and still be a photon?

Everything above absolute zero is not at rest.

Unfortunately, the real answer is messy. See item #4 in the Physics
FAQ:
"Do Photons Move Slower in a Solid Medium?"
http://www.physicsforums.com/showthread.php?t=104715


--
Jeff Liebermann
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Santa Cruz CA 95060 http://802.11junk.com
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