Comment by galacticbyte on 20/07/2023 at 00:58 UTC*

1 upvotes, 1 direct replies (showing 1)

View submission: After the universe reaches maximum entropy and "completes" it's heat death, could quantum fluctuations cause a new big bang?

Heat death is unlikely the full answer, for the following reasons:

1. it is only a statistical statement. Entropy on average sure will likely increase but occasionally it does decrease

2. there is a quantum recurrence theorem stating that given sufficient time, it will reach arbitrarily close to any state, including the initial state of the Universe.

3. recent work also stats that thermal equilibrium doesn't mean there is no more evolution. See Susskind et al's work https://arxiv.org/abs/1701.01107[1][2]. Complexity does continue to increase

4. the vacuum structure isn't necessarily stable so decay could happen (even if super tiny, since we're talking about eternity here)

So yeah as soon as there are more interesting vacuum structures, pockets of the Universe really could start a big bang like process all over again.

1: https://arxiv.org/abs/1701.01107

2: https://arxiv.org/abs/1701.01107

Replies

Comment by jisei_ at 06/12/2023 at 21:01 UTC

1 upvotes, 1 direct replies

Could you elaborate on the first point? I don't see the relevance in mentioning the occasional decrease in entropy given the fact it's irreversibly generated and can overall only be increased, which is the whole point behind the heat death theory.