

Dr Hawking's bright idea has turned up in an unexpected place - davidedicillo
http://www.economist.com/node/17144843?story_id=17144843

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ithkuil
I thought that speed of the light in a medium can be slower that that in
vacuum just because of the fact that it takes more time to be absorbed and re-
emitted by atoms, i.e. photons actually continue to travel at the same speed,
but they are not the "same" photon.

