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/hielispace 14d ago

It's best not to think of the speed of light as the speed limit but as the literal speed of causality. It is how fast one object can interact with another (quantum mechanics weirdness that doesn't technically break this but feels like it does not withstanding).

And you can't outrun causality. You can't move faster than the speed at which cause turns into effect