Does this theory of how the Universe will end seem realistic? Why or why not?

Question

Since the big bang, the universe has been constantly expanding, propelled by the initial "big bang", and it will continue to expand, because there is no force to stop this initial momentum. As the universe expands, it is slowly getting colder and colder, so theoretically eventually it will get so cold that stars will no longer be able to burn their hydrogen and helium through nuclear fusion, and all stars will die out, along with all other heavenly bodies which will be sucked into the black holes formed by the dying stars. but as the universe continues to expand, not even the black holes will be able to support themselves, and they too will collapse, leaving the universe to be a completely and utterly empty space devoid of any and all material and matter with the temperature being only a few degrees above absolute zero

Thus ending the universe

Answer 1

I don't think the fusion that goes on in the cores of stars is dependant on the temperature of the universe.  It's dependant on the balance between pressure and gravity, in the star itself.  So I don't think stars will "burn out" if the universe get too cold.  

Also, not all stars form black holes at the end of the stellar life cycles.  Only the massive ones (I think 8 solar masses or larger) can form a black hole.  

And I think a black hole supports itself regardless of the conditions around it.  All a black hole is is a stellar remnant of super dense matter with super intense gravity.  I think there are black holes that continue to exist even when they are not "fed" matter by a companion star (meaning, they do not accrete matter).

Answer 2

Duane is right. What if there was enough matter (gravity) in the universe to slow the expansion and then start the Big Crunch.

The universe is now accelerating. Some believe this is due to "dark energy".  Some believe the universe might continue to accelerate in its expansion -- "Big Rip".

http://fire.biol.wwu.edu/trent/alles/Cos...

Answer 3

That is close to being the theory called "the big chill." However, it is a little wrong, semantically.

The universe spreads out, yes. The stars won't cool down until they no longer function, though. Rather, they will use up all the fuel. As the gas media throughout the universe expands, less and less new stars will form to replace the ones that are exhausting their fuel. Thus, more stars will run out and cool off than new stars will be created until there are no stars left.

Matter will continue to spread out due to momentum and diffusion (entropy). Eventually, the protons composing much of the matter existing in space and in burned out stars and in planets will  decay away until there is no more conventional matter. This is occurring right now, but it is so slow that is won't affect the universe until long after it is frozen and dark.

Then, the black holes will not collapse. Every black hole radiates a little of its mass into space at any given time. It is reasonable to assume that most are absorbing more mass than they loss in this way. But given eons in a cold universe, they will eventually begin to evaporate away.

At this point, once every recognizable mass has dissipated or decayed away, the universe will utterly cold and spread out uniformly. At this point, quantum effects will begin to become significantly relevant. It is possible that almost anything could happen, including a spontaneous big bang to start it all over again.  

This need not be a depressing thing. If we ever existed that long we would have some way to spare ourselves oblivion. By that time, the 40,000 years we have been around could have been lived millions of times over.

Answer 4

Interesting concept.  But you mention that there would be empty space remaining that would be devoid of any and all material.  Wouldn't that still constitute a "universe", however inanimate?

Answer 5

Pretty close and yeah, that is about how they think it will end now.

A few corrections.

First, the stars will not burn out because it is getting colder.  It is only a few degrees above absolute zero out there today.  Eventually the stars will just burn all available fuel.  Stars can only fuse up to iron and then only the biggest ones.  Iron is a net energy loss when fused so it could not form a star.  Eventually there will be no fuel left to form gas clouds that will coalesce into new stars.  That last ones will burn out and then slowly evaporate into space.

Second, most stars will not form black holes.  Only big ones will.  Most of the matter in the universe will not find its way into a black hole.  Plus, even black holes evaporate via Hawking Radiation (albeit very slowly) so someday even they will disappear.

Third, the universe will not be "empty" as such.  You will just have particles floating here and there sort of smeared out evenly all over space.  They will not do anything though.  They will be near absolute zero and forever approaching absolute zero.  There will be no available energy to do anything.

In the end the universe will be a cold, dark, dull place.

Answer 6

I guess that it seems to be somewhat plausible. I would not call it a fantastic description of its cause. However, the ending is meaningless. You say that the universe is devoid of material, yet it is a few degrees above absolute zero. Absolute zero refers to the relative motion of atoms. If the temperature is above absolute zero, then there must be motion among atoms. This is not possible if there is no matter in the universe.

Answer 7

that's the 'heat death' idea..... and I don't buy that one.... one of the first 'laws' I learned was the one about how energy cannot be created or destroyed, only changed..(The first law of conservation of mass says that energy cannot be created nor destroyed. )... and I look around at the Universe that's closest to me, and things are constantly being changed.... energy into light... matter into energy... the Earth recycling life itself....and I thereby believe in the Universe 'changing' or recycling, too....

I think there's something that we've yet to find out , that will show us that the Universe will actually do a Finnegan......

Answer 8

Based on the current models of our universe, this appears to be the most feasible fate.  However, we certainly don't have anywhere near enough information to know exactly how, or even if things will end.  There are other theories out there, including the "big crunch" (the universe collapses back into itself, compressing itself back to how things were immediately before the big bang).

Answer 9

Nobody will ever know for sure b/c we'll all be dead long before the universe ends...unless, of course, we're all in an alternate universe:)

Answer 10

I believe your talking about the Heat Death of the universe.

http://en.wikipedia.org/wiki/Heat_death

This is the most compelling theory so far in my eyes.

If the universe does continue to expand then yes, star will burn up most of the hydrogen, the universe will go dark, and black holes will slowly consume everything. A few hundred billion years later the black holes will evaporate due to theorized Hawking Radiation so we will just have a bunch of particles speeding off into the near infinity of space.

Bleak, but the truth isn't there to remind you of warm blankets and apple pie.

^^

Answer 11

how do you know there will be no force to stop it?