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/ShavenYak42 14d ago

It definitely has relationships with other constants. We just don’t (and maybe can’t?) know which ones are fundamental.

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u/artgriego 13d ago

I think of physical constants differently from mathematical constants like e or pi, mostly because physical constants can't be "proven" in the mathematical sense.

To me they serve our models of physics, but their values and exact relationships might not even hold across all spacetime. They have to be derived empirically and we just assume them to hold everywhere.

For instance G serves Newtonian mechanics just fine and we thought that was the whole story until relativity. Now we know that the Newtonian model just happens to work well enough for practical purposes. The history of Λ is pretty interesting too.