What would an infinite universe look like to us?

[Magical Realist]

Would it look any different from a finite one? And how would it effect the probabilities for anything happening at any given point? While you're ruminating on that, here's a little video explaining the strange implications of an infinite universe.

https://www.google.com/search?q=how+to+t...oCsRI,st:0

[Zinjanthropos]

Video in OP just a black screen, is that on purpose?

“In 5 billion years, the expansion of the universe will have progressed to the point where all other galaxies will have receded beyond detection.”

….Lawrence Krauss

Should a civilization pop up in any of those galaxies, what would universe look like to them? Finite?

[Magical Realist]

Youtube version of the same video...

https://www.youtube.com/watch?v=Al9EyNoCsRI&t=332s

[geordief]

My take is that there is no such thing as identical copies of things that have already existed.

Something with the same identical structure will always have a different history and so the apparent paradox in an infinite universe just does not present itself.

The different histories mean that any such identical structures will only exist for the shortest possible length of time and immediately evolve into something else.(differrent)

If the structure has any internal constituent parts then the same applies to them-in spades.

So that entire video is pure bunkum in my view.

Hope he makes a few bob.

[Magical Realist]

"In a multiverse, one cannot avoid infinity, and infinity does strange things. There are two types of possible infinities in a multiverse: Type I: A single universe may be infinite in size (e.g., in our universe, if space and galaxies would continue forever without end or closure), or Type II: All the separate universes in a multiverse can be infinite in number (irrespective of whether any or all of the universes are infinite in size themselves).

The consequences of either infinity become bizarre. First of all, even Tegmark's Level I multiverse, assuming it's infinite, must contain everything that's physically possible. This means, for example, that every "Star Wars" scenario really exists out there, including those that didn't make it into the films and even all those the writers didn't think of!

Similarly, as long as there is sufficient space for unending random shufflings of particles (and a universe of infinite size certainly has sufficient space), there would have to be a sector of space out there identical to our sector of space, with persons identical to you and to me. Tegmark estimates that our closest identical copy is 10^10^28 m away.

I'm not so impressed even by this bizarre proposition. There would also have to be a sector of space identical to our sector of space except for, say, one hair on the head of one person, which is skewed 1 nanometer to the right. And another sector of space in which all else is the same except for that same hair, which is now skewed 2 nanometers to the left. Then all the hairs on all the people, skewed this way and that way. And then all the things in whole sectors of space, arranged in every possible combination and permutation. There would be innumerable minute differences and innumerable large differences, with every one a separate sector of space — all enabled because the one infinite universe with infinite sectors of space goes on forever. Obviously, on this vision, randomized particles in the overwhelming majority of vast sectors of space yield nothing much at all.

To be clear, a truly infinite universe means that anything that is not impossible (no matter how obscure) will happen, must happen and must happen, weirdly, an infinite number of times. An infinite universe goes on forever, not only generating uncountable variations, but also requiring each of the uncountable variations to occur an infinite number of times. That's the strange nature of a true infinity."--- https://www.space.com/31465-is-our-unive...verse.html

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My take is that there is no such thing as identical copies of things that have already existed.

Something with the same identical structure will always have a different history and so the apparent paradox in an infinite universe just does not present itself.

The different histories mean that any such identical structures will only exist for the shortest possible length of time and immediately evolve into something else.(differrent)

If the structure has any internal constituent parts then the same applies to them-in spades.

But in a truly infinite universe, one that goes on forever and ever, there would eventually have to be a universe where all the histories of every object in our universe would be identical, and an infinite number of such as well. But there would also exist an infinite amount of universes where the history of one given object is identical to one in our universe except for one event, and then except for two events, and so for all the events in all the histories of all the objects in our universe, and then for all possible combinations and permutations of those events for each and every history of all the objects, and all possible numbers and combinations and permutations of the set of all histories, and etc and etc! We are talking staggering numbers of universes at this point, the vast majority of which would be totally indistinguishable and superfluous.. Such a endless profusion of infinities becomes almost absurd at some point. One even has to go into Cantor's transfinite sets to make sense of it all. In any case, even if infinity isn't real, it is certainly a mind-boggling concept!

[geordief]

But in a truly infinite universe, one that goes on forever and ever, there would eventually have to be a universe where all the histories of every object in our universe would be identical, and an infinite number of such as well. 

I am completely unconvinced.When two sets of circumstances  have the same  identical khistories it is plain to me that they are not only identical but the same.

Not a bit mind  bending or bizarre ,just commonplace.

As a corollary (not the reason I find it convincing) it aĺows for an infinite universe without paradoxes.

A universe can ,imo be infinite without having to tie itself in knots and repeat itself endlessly.

I have no idea if the universe is infinite or finite.Perhaps it is both.

[Magical Realist]

I am completely unconvinced.When two sets of circumstances have the same identical khistories it is plain to me that they are not only identical but the same.

Not a bit mind bending or bizarre ,just commonplace.

That is a provocative issue in itself--the threshhold between between identity and the identical. Leibniz formulated it like this:

"The identity of indiscernibles is an ontological principle that states that there cannot be separate objects or entities that have all their properties in common. That is, entities x and y are identical if every predicate possessed by x is also possessed by y and vice versa."

In the same universe, two things that share the same history and properties WOULD be the same and indistinguishable. But if those two things are in two different universes, then there is at least one thing they don't have in common, and that is being in their own universe. IOW, they maintain their identity in spite of being identical--two identical things in two, at least spatiotemporally, different universes. But then if those two universes are themselves identical in all respects, then I guess they would be the same and we end up back in one universe where the one thing is simply being its unique itself!

[C C]

Would it look any different from a finite one? And how would it effect the probabilities for anything happening at any given point? While you're ruminating on that, here's a little video explaining the strange implications of an infinite universe.

https://www.google.com/search?q=how+to+t...oCsRI,st:0

Since "infinite" can't be a physically completed condition or quantity without thereby contradicting itself as finite, the adjective has to be referring to something else. Whether the scientists or philosophers espousing such are consciously aware of that fallacious artifact of their thinking or not.

The "something else" that infinite is instead designating could either be that the universe is constantly or intermittently adding "more" to itself over time. Or that "infinite" actually does confusingly refer to an incredibly large finite magnitude (one that is indefinite rather than precise value like googolplex).

Such an immense finite magnitude could (in theory) still sport all possible structural configurations eventually being exhausted, so that they begin repeating themselves (in theory). That's the thing about "finite" -- it can stay on the tail of a "never ending process" as long as it wants before finally quitting...

Finity, delaying its end, did say:
Like a flea attached to its beast, I stay!
I vow, quoth Infinity, so you do.
And feeding from my very ichor, too!

[Magical Realist]

Such an immense finite magnitude could (in theory) still sport all possible structural configurations eventually being exhausted, so that they begin repeating themselves (in theory). That's the thing about "finite" -- it can stay on the tail of an "infinite process" as long as it wants before finally quitting...

Finity, delaying its end, did say:
Like a flea attached to its beast, I stay!
I vow, quoth Infinity, so you do.
And feeding from my very ichor, too!

So true. At any given point in infinitude's ever burgeoning expanse, finitude need only ever be infinitude - X. Unless that is just another name for infinitude as it would never end either!

[geordief]

I am completely unconvinced.When two sets of circumstances  have the same  identical khistories it is plain to me that they are not only identical but the same.

Not a bit mind  bending or bizarre ,just commonplace.

That is a provocative issue in itself--the threshhold between between identity and the identical. Leibniz formulated it like this:

"The identity of indiscernibles is an ontological principle that states that there cannot be separate objects or entities that have all their properties in common. That is, entities x and y are identical if every predicate possessed by x is also possessed by y and vice versa."

In the same universe, two things that share the same history and properties WOULD be the same and indistinguishable. But if those two things are in two different universes, then there is at least one thing they don't have in common, and that is being in their own universe. IOW, they maintain their identity in spite of being identical--two identical things in two, at least spatiotemporally, different universes. But then if those two universes are themselves identical in all respects, then I guess they would be the same and we end up back in one universe where the one thing is simply being its unique itself!

I think you  may have argued the point I was trying to make.