If the universe is infinite, does EVERTHING necessarily exist?

[TheTrueCentrist]

Originally Posted by Qoeleth

Now, the possibility of an infinitely repeating universe, if the universe is temporally infinite, but spatially finite Let me prove it. Let's imagine a particular state of the entire universe (down to the arrangement of every single atom in the universe), at a given point in time. Now, if the universe is infinite in time, sooner or later that exact state is bound to re-occur (as a non-zeroproability event). Once it does re-occur, everything will necessarily repeat in exactly the same way. So, a temporally infinite (but spatially finite) universe is necessarily a repeating universe.

That assumes determinism. There may be non-deterministic effects which mean that even if the universe reaches the same state twice, what follows may not be identical. Nevertheless, it would still be possible for there to be true repetition. However, the repetition would not be on any sort of regular interval.

If the universe was finite in size but not time, it would be impossible for something spatially larger than the universe to exist within the universe. Therefore, not everything would exist.

[inocente]

Originally Posted by Qoeleth

Now, the possibility of an infinitely repeating universe, if the universe is temporally infinite, but spatially finite Let me prove it. Let's imagine a particular state of the entire universe (down to the arrangement of every single atom in the universe), at a given point in time. Now, if the universe is infinite in time, sooner or later that exact state is bound to re-occur (as a non-zeroproability event). Once it does re-occur, everything will necessarily repeat in exactly the same way. So, a temporally infinite (but spatially finite) universe is necessarily a repeating universe.

Sorry but not in this universe if it is spatially finite but continuously expanding. That means the universe is a bit bigger with every successive state, and therefore no state could ever exactly re-occur without also reducing the size of the entire universe back to what it was when it first occurred.

[Alberti_Devoveo]

Originally Posted by Qoeleth

Let us assume that the universe is infinite, either temporally or spatially.

That would seem to imply that EVERYTHING which is possible, must exist, someplace or sometime. Every combination of atoms must occur as some point. Let me illustrate- take a 5,000 carat, flawless, red diamond. The chances of that particular combination of atoms might be 0.000000000001% (even less, but you get the idea!). Now, in an infinite universe, that highly improbable combination must occur, sooner or later.

The same could be said of a unicorn, or a perfect doppelganger of any person. Or, like an infinite number of monkeys at typewriters- who will sooner or later write "Hamlet". Or the infinite Library in Borges' story.

Now, in defence of the claim that the universe is spatially infinite, I cite Luctetius' story of the spear- go to the 'edge' of the Universe, and throw a spear- there is either more space, or more matter, thus the Universe continues. In either case the Universe must be infinite.

Now, Lucretius argues that if the Universe is infinite spatially, there must be an infinite amount of matter too, Otherwise the matter would be infinitely diluted in space, and never come into contact with each other.

Thus it would seem that everything which is possible to exist, must exist.

If we assume that type of infinitude, then yes anything with a non-zero probability of occurring ought to occur during that infinite span of time--this is classic statistical mechanics.

[Alberti_Devoveo]

Originally Posted by TS Aquinas

I believe, if I'm not mistaken, that physics say the amount of energy required for an oscillation or the Big Church theory exceeds the amount of energy left in the universe. If retraction would happen, we'd already see it happening and not expanding at a faster rate than before. All signs point to the Big Chill theory. I could be mistaken about this, I'll leave it to one of our regular posting physicists to correct or elaborate on.

The only potential saving grace, if you will, of the big crunch theory is dark matter. Assuming it exists in large quantities, it is still theoretically possible that the dark matter could reverse the acceleration of the expansion. Current observations are pointing away from the big crunch theory.

Originally Posted by THP

Hmmm. . . At the same time in the article it notes that 95% of matter/energy is "dark" and we can't directly measure it. Fun to ponder, I wish I was better at math.

Dark is somewhat of a misnomer, especially when discussing both dark matter and dark energy. Giving them the same prefix seems to indicate that they are related to one another, but this is not the case! Only the fact that we cannot detect them is what makes them related (and gives them the prefix 'dark').
Dark matter is the hypothetical particle that only acts via gravitational forces; dark energy, on the other hand, is the hypothetical energy that is causing the expansion of the universe.

[TS Aquinas]

Originally Posted by Alberti_Devoveo

The only potential saving grace, if you will, of the big crunch theory is dark matter. Assuming it exists in large quantities, it is still theoretically possible that the dark matter could reverse the acceleration of the expansion. Current observations are pointing away from the big crunch theory.

Or something crazy like Maxwell's demon.

[johnnyjones]

Only God is infinite. The universe ends because it was created. Of course you can always choose to believe in infiite matter which in turn is a sort of god.

[John of Woking]

My head hurts