« on: Today at 06:55:50 »
Quote from: OP
Lots of astrophysicists tend to agree on the big crunch,Not since the discovery of the accelerating expansion of the universe, in the 1990s.
There is a hypothesis that during the Big Bang, there was a period of "inflation", where the size of the universe grew very rapidly.
- This left an imprint on the Cosmic Microwave Background Radiation
- The rules of physics would have been radically different before that - for example, it is thought that the 4 fundamental forces that we know today may have had similar strengths (today, gravitation is far weaker than the other forces). Effectively, it would have been like a very different universe
- There is a hypothesis that this could happen again, with runaway expansion - the Big Rip
- And in fact, vacuum energy could produce a series of such state changes in the universe, with perhaps different physics in each epoch.
Whether we can detect the influence of other universes from inside our own depends on how well isolated different universes are.
- There have been suggestions that maybe there are subtle effects in our universe that can't be explained by things that we can see within our own universe, but you would have to say that is very speculative
- After all, we have Dark Matter & Dark Energy that we don't have good explanations for, as yet, and these do have good observational evidence for their existence...