Is there a prediction for the heat death of the universe?

Is there such a thing, anyway? And what do most physicists figure about the ultimate expansion of the universe? Are these two concepts linked? (e.g., which comes first:confused:).

The most common theories these days are that the universe will either end in a heat death, as the average temperature goes toward absolute zero, or in a Big Rip, as dark energy tears the universe apart:

Interesting. I hope it isn’t too impertinent to mention related comments by one of my favorite poets:

Of course, Frost was aware of the cosmological debate at the time, and was deliberately referencing it. As, for that matter, was T. S. Eliot, whose “The Hollow Men” ends with “This is the way the world ends, not with a bang but a whimper”.

Basically, the heat death is how the Universe will end if it doesn’t end in some other more decisive way first. It used to be that the decisive end that everyone talked about was a Big Crunch, sort of like the Big Bang in reverse, but current data seem to make that quite unlikely (it would require that something happen to stop or reverse the dark energy, which we can’t rule out, given how little we know about it, but isn’t something to bet on). Nowadays, the most plausible decisive end would be a Big Rip, where the dark energy gets stronger with time, eventually getting strong enough to overwhelm everything else. The data actually seem to slightly favor this possibility, but nobody has any theoretical basis for saying that it should, and the data are also consistent with the simpler possibility of the dark energy staying at a constant strength, so for now at least Occam’s razor says to reject it.

Are you trying to determine if it will be on a weekend?

One more nail in the coffin of the Anthropic Principle and the various inane “philosophies” that put the human existence and experience in the center of cosmology.

I’m side-chaining on another thread regarding philosophical ideas and their relevance to humans, the universe, or to reality.

The time scale of heat death is incomprehensible to our mental capability, but still, we can put 2 plus 2 together and come up with a reasonable answer, not a fantastic or magical one, or a wishful thinking one, like most philosophical or religious ideas are all about.

But, who knows, heat death may not necessitate the absence of intelligence as we know it.