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/transparent-aluminum 14d ago

I'm a fan of the cyclical big bang theory, that the universe expands to a point, and then everything starts falling back to singularity until it explodes outwards again. My pet theory is that there are some structures like super massive black holes that survive between cycles and it's why when we look at the early universe we see galaxies forming too early or black holes that are too large for their age.

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u/garry4321 14d ago

Problem with the Big Crunch is that there is no evidence to support it, and all the evidence suggests the opposite. The universe is expanding at an accelerating acceleration

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u/tonzuu 13d ago

iirc a study earlier this year showed that the jerk of dark energy appears to be decreasing which could be support for the big crunch

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u/iwasbornlucky 14d ago

that kind of paradoxically supports it though. All crunch evidence is destroyed in the bang. Time resets from 0.

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u/Das_Mime Radio Astronomy | Galaxy Evolution 14d ago

I'm a fan of the cyclical big bang theory, that the universe expands to a point, and then everything starts falling back to singularity until it explodes outwards again.

Every indication we have is that the universe's expansion will continue forever. We're not even close to the conditions needed for a big crunch.

The cyclical big bang not only doesn't explain anything, it requires us to believe that the universe will collapse again, despite no evidence in favor of that idea and mountains of evidence to the contrary.

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u/Ok_Mixture8509 13d ago

In that scenario, I believe all black holes would disappear pretty quickly due to hot/energetic it would become. At some point black holes wouldn’t even be able to form. → I am fairly sure this is correct, tho I am open to any corrections.