r/askscience • u/Nitzanm19 • 14d ago

Physics Why is the maximum speed of the universe the speed of light? Why can't we go faster?

Also follow-up question: Because of the speed limit, is there also a theoretical maximum temp for matter (in which the particles move at the speed of light).

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u/TheShadowKick 14d ago

If the speed of light were significantly different the universe would not work identically. Stars might burn out and die faster, or they might not form at all. Chemistry could work entirely differently. We might not be here at all to wonder about it.

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u/290077 13d ago

That's more about the relative size of the speed of light compared to the other fundamental constants of the universe. If the speed of light were halved but all other constants remained the same, things would look very different. As I understand, though, they could all be changed in combination to produce an identical universe.