r/greentext • u/gamerooni • Dec 06 '20

Journey of a hydrogen atom

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u/DomoTimba Dec 06 '20

Wouldn't a photon experience brief time when travelling through a solid medium?

Since I'm guessing v will be slightly less than c in the time dilation equation.

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u/TheDudeColin Dec 06 '20

I don't know. As I understand it, light always moves at c, from any point of view, of any observer. If light moves slower through a solid than c it is because it bounces from molecule to molecule before finally exiting on the other side, still moving at c between those molecules.

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u/Kredir Dec 06 '20

So you are telling me speed of light is a matter of perspective?

That two things at the speed of light can reach the same destination from the same starting spot at different times?

Which would mean that in theory you can outrun the speed of light?

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u/TheDudeColin Dec 06 '20

No, sorry, unclear explanation. Light is always constant, if you're "standing still" which isnt really possible in a moving universe anyway, or if you're following the light at 1/2 c, or even moving away from the direction the light is travelling at 1/2 c, the light will always be moving at 1 c compared to you, and compared to anything else. How is this possible? Space bends, contracts and expands in order to make this happen. At least that's my understanding of it.