# Black holes and a Hot death

1. ### zanazzi78

110
I have a question about the hot death model of the end of the universe.

If the current expansion of the universes was to slow down and eventually the universe started to contract ( I know very unlikely but…) would the matter in the universe coalesce into black holes, before the temperature and pressures got so high as to turn matter into pure energy?

If some/most would then would these super massive black holes be affected by the temperatures and pressures?

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3. ### Chronos

10,060
That's a tough one, all right. In a collapsing universe, you would still have the illusion that you were at the center of the universe. Some people would find this.... unsettling.

In a collapsing universe [at least in principle] spacetime itself would be collapsing. It is difficult to imagine [not to mention calculate] what would happen as the end[?] drew near [aside from it being unpleasant to anything still living]. In the cyclical universe model [at least the model I am most familiar with], another big bang would result.

4. ### zanazzi78

110
Im not talking of time scales close to the big crunch.

Am I correct in thinking that when the universe was 300000 years old photos "broke free" from the radiation and flooded out into the expanding universe, we see this in the COBE and MAP images of the Cosmic background radiation.

Going back to a point approximatly 300000 years before a big crunch, matter density would be comparable so would tempareture. Matter would break down, but we now have blackholes, where as they didint exist at the start of the universe! could they black holes 'eat' the radiation around them and survive to "the end"?

I`m thinking that the big crunch would never happen. That all matter would fall into blackholes and that all black holes would merge leaving behind one single super super massice blackhole.

5. ### Flatland

159
From what I understand if everything in the universe merged into a blackhole at that point you would just have the big bang singularity no?

6. ### Spin_Network

408

But what you are left with then, is a multitude of Particle Production Factories:

http://www.superstringtheory.com/blackh/blackh3.html

so, there may be some form of 'matter-energy' symmetry "reconfiguration"?