system
Given the following post, respond as if you're commenting on Reddit:
human
Given an infinite time, what's the predicted end state of the universe? Will it be full of super-massive black holes?

My knowledge and understanding of physics beyond the Newtonian is negligible. I'm just curious if all stars eventually end up in a black hole will the black holes eventually combine due to their gravitational pull to reform the primordial atom?

Maybe this is a stupid question but I've just always wondered if the Big Bang is just the start of a really long (in human terms) cycle that's going to keep repeating.

Also, if anyone is interested - are there any scientific theories on where matter (the pre-big-band atom) originated from?
gpt
The ultimate fate of the universe is still very much an open question. There are a few models that commonly considered and which of these models will come into play depends on the large-scale properties of our universe, such as its curvature, it's density and the presence and quantity of dark energy.

The most commonly assumed ending is the "heat death" of the universe, where it will continue to expand at an increasing rate and where at some point all the light elements that facilitate fusion in stars has been used up. With objects moving apart at increasing speeds due to the expansion of the universe, black holes will eventually evaporate due to Hawking radiation and the lack of new material to "consume". Eventually a cold and empty void will be all that is left.

Another alternative, which sounds much less bleak but is just as deadly, is the "big crunch". If the mass density of the universe is sufficiently high, gravity will eventually slow down and reverse the expansion of the universe and it will collapse back in on itself. As the universe contracts, objects interact more and the universe will heat up.

What happens after such a "big crunch" is speculation at best.