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generally infinite How infinite is "generally infinite"? Are we talking infinite enough it's not productive to talk about its size, or so infinite there are ph

generally infinite How infinite is "generally infinite"? Are we talking infinite enough it's not productive to talk about its size, or so infinite there are physical copies of the solar system, earth, and everyone it it by sheer chance?

zuminator 3y ago
My apologies. By "generally infinite" I merely meant "generally thought of as infinite," not like I was invoking some special class of nigh-infinitude. By the way, I wouldn't say an infinite universe doesn't necessarily imply that everything exactly repeats. Take any irrational number like pi. We know for a fact that it doesn't repeat itself exactly because if it did, it would not be irrational. Although it seems likely that pi is "normal" and that any finite segment of it will repeat infinitely many times, that is not a requirement of all infinite numbers. One could imagine a number called pu where every 9 but the first is replaced with a 0. So, 3.1415926535807032, etc. What can we say about pu? It a) is an actual number with a precise definition, b) is infinitely long, c) is aperiodic thus irrational, but d) only has one 9 in its entire infinitely long decimal expansion. Similarly, the cosmos might conceivably have some "one off" features that never repeat, even if it is infinite. But I still haven't answered your question. My answer is, yes, if spacetime curvature is exactly 0, then it's my understanding (as a non-cosmologist) that the equations imply that the universe is that infinite such that conceivably everything could in principle repeat an infinite number of times. Although I myself am curious what the estimated size of just the non-repeating part would be.
- causality0 3y ago
  Whether the creation/generation of the universe created copies of highly specific configurations like our solar system, given an infinite volume of space, wont quantum fluctuations spontaneously produce copies of it out of empty space?
russdill 3y ago
There's some very weird edge cases when it comes to infinity and the size of the universe.

zuminator 3y ago

My apologies. By "generally infinite" I merely meant "generally thought of as infinite," not like I was invoking some special class of nigh-infinitude. By the way, I wouldn't say an infinite universe doesn't necessarily imply that everything exactly repeats. Take any irrational number like pi. We know for a fact that it doesn't repeat itself exactly because if it did, it would not be irrational. Although it seems likely that pi is "normal" and that any finite segment of it will repeat infinitely many times, that is not a requirement of all infinite numbers. One could imagine a number called pu where every 9 but the first is replaced with a 0. So, 3.1415926535807032, etc. What can we say about pu? It a) is an actual number with a precise definition, b) is infinitely long, c) is aperiodic thus irrational, but d) only has one 9 in its entire infinitely long decimal expansion. Similarly, the cosmos might conceivably have some "one off" features that never repeat, even if it is infinite. But I still haven't answered your question. My answer is, yes, if spacetime curvature is exactly 0, then it's my understanding (as a non-cosmologist) that the equations imply that the universe is that infinite such that conceivably everything could in principle repeat an infinite number of times. Although I myself am curious what the estimated size of just the non-repeating part would be.

causality0 3y ago
Whether the creation/generation of the universe created copies of highly specific configurations like our solar system, given an infinite volume of space, wont quantum fluctuations spontaneously produce copies of it out of empty space?

russdill 3y ago

There's some very weird edge cases when it comes to infinity and the size of the universe.