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Relativity/speed of light question #1


OK...this question has bugged me for a long time, and I have even been on physics forums trying to get an answer. I read an article suggesting that a Shadow can travel faster than the speed of light, (or in a similar circumstance so can a laser). If you have the shadow cast on a wall extremely far away...and you... show more




Best Answer:  Let's say that your shadow is cast on a wall 1 light year away. The shadow does not move for a whole year, and you don't see it move for another year, that you can see the shadow (then , finally) move some vast distance... you have *moved* _nothing_. Light that was arriving in one place, was blocked elsewhere.

I think I've answered your faster than light question. However you decide to modulate the light beam, the beam still travels at c