# Is it possible that there are an infinite number of universes? **URL:** \ **Category:** Factual Questions\ **Created:** [June 20, 2023, 2:12am UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802 "2023-06-20T02:12:22Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [June 21, 2023, 12:46pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/41 "2023-06-21T12:46:16Z")
> [@Andy\_L](#): > > It would be weird to have exactly 59 universes - the choices that seem possible to me are: 1, infinity - or zero (with the last excluded by fairly reliable evidence). Almost right! Actually, it’s 57. How do you think, “Heinz 57 Sauce”, got its name? There is a version of it in all 57 universes. In fact, if you and another version of you in another universe pour the product at the exact same moment, it creates a Rosen-Einstein Bridge connecting the two points. Hasn’t happened yet, but just wait! ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 21, 2023, 5:04pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/42 "2023-06-21T17:04:27Z")
Or as Asimov put it in The Gods Themselves (incidentally, about the same question), “Two is an impossible number”. The plot was that scientists in our universe had made contact with scientists another universe where the fundamental constants were slightly different, and were trading isotopes that were stable in one universe but unstable in the other, so as to provide cheap, clean energy for both. But there was a problem that came up with that, the resolution of which was that if there are two universes, there must surely be more. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [June 21, 2023, 6:02pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/43 "2023-06-21T18:02:48Z")
> [@ftg](#): > > > [@msmith537](#): > > > > There is another school of thought that even in a single infinite universe like ours, there are actually a finite number of ways to organize a bazillion trillion molecules. So if you travel in the same direction long enough, you should encounter another version of Earth, or a version or Earth where the Brooklyn Bridge is blue, so on and so forth. But that’s more like the same universe endlessly repeating (which it can do because it’s infinite). > > Every once in a while some Physicists who don’t understand a bit of Cantor’s work suggest this. > > And they are flat our wrong, just on the Math alone. Throw in the Physics of the history of a 2nd Earth having to be identical as well, quantum events and all, and you’re talking about a literally laughable conjecture. > > Whenever I see someone talking about “could there be an infinite number of …” the first question is what do you mean by “infinite” in terms of the Cantor hierarchy? There could be countably infinite universes, or a continuum equivalent number, or even higher. I think they mean “infinite” as in if you head off in any direction you would continue encounter stars and asteroids and galaxies and whatnot forever. I suppose it could just be endlessly repeating “noise” forever, but that seems unlikely to me. Of course what does that actually mean? The universe is 13 billion years old and with expansion the visible universe is around 46 billion light years across. And eventually the universe will burn out or collapse on itself or however it ends, so even if you kept going forever, at some point you’d just be travelling in black nothing. The point being is that even if it were mathematically possible that another duplicate or near duplicate Earth formed a trillion billion bazillion light years away, it seems kind of irrelevant. We could never observe it and all of creation would evaporate into it’s component particles before anyone or anything could ever reach it. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [June 21, 2023, 9:57pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/44 "2023-06-21T21:57:29Z")
I wonder why this is still posted in Factual Questions. Seems to me that it should be in a forum where fanciful notions and unanswerable questions can be discussed or even debated. Aside from a simple “yes” how could anyone answer this question factually? (I anticipate someone pointing out that “yes” is a factual answer. Ok.) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 21, 2023, 10:17pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/45 "2023-06-21T22:17:07Z")
It’s still in FQ because there’s a lot factual to be said about the subject. There are a number of recognized notions of something that could be called a “multiverse” in physics, and it’s meaningful to discuss the implications of those. ---
**Author:** ![E-DUB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/e-dub/32/403_2.png) [@E-DUB](https://boards.straightdope.com/u/E-DUB)\ **Post date:** [June 21, 2023, 10:32pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/46 "2023-06-21T22:32:11Z")
There was a short story by Randall Garret in which it was possible to travel from one universe to another but only by harnessing all the energy in the universe you were leaving behind. The title, of course, “Infinite Resources”. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [June 21, 2023, 10:43pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/47 "2023-06-21T22:43:52Z")
If I did my math right, it’s also 10e10e115 universe radii or and 10e10e115 proton radii (to the precision given) ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [June 22, 2023, 1:10am UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/48 "2023-06-22T01:10:33Z")
> [@E-DUB](#): > > There was a short story by Randall Garret in which it was possible to travel from one universe to another but only by harnessing all the energy in the universe you were leaving behind. The title, of course, “Infinite Resources”. If I’m harnessing all the energy in the universe, am I really traveling to another universe or simply rearranging the current one into a new desired configuration? ---
**Author:** ![E-DUB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/e-dub/32/403_2.png) [@E-DUB](https://boards.straightdope.com/u/E-DUB)\ **Post date:** [June 22, 2023, 2:19am UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/49 "2023-06-22T02:19:24Z")
The guy who did this literally knew that he was killing all the inhabitants of the “prior” universe. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [June 22, 2023, 4:44am UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/50 "2023-06-22T04:44:55Z")
> [@Chronos](#): > > \aleph\_0 is a countable cardinality Quite right. Mea Culpa. \aleph\_1 is the first uncountable. My memory is not what it was. (It has been 40 years since I studied this stuff. That is my excuse anyway.) ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [June 23, 2023, 10:35pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/51 "2023-06-23T22:35:27Z")
> [@Chronos](#): > > Cantor’s work is irrelevant to this, because it’s all about finite numbers. The chances of another planet being indistinguishable from Earth are really, really small, but they’re not zero. As well as others that replied to my post. Folks, please note the post I was responding to. 1. The poster specified a **single** Universe. No multiverse. 2. The point was that in a given direction you would definitely (as in 100%) come across a 2nd Earth. That’s a much bigger than “really, really small”. 3. I considered the notion of “travelling” in a given direction a metaphor. That this was a theoretical concept of what is going on somewhere far, far off in a arbitrary direction _sans_ any hope of a person making the actual trip. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 24, 2023, 1:03pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/52 "2023-06-24T13:03:13Z")
Right, any given spot in the Universe has only a very, very small chance of being identical to here. If there are enough spots in the Universe, though, then even with the odds being poor for any given one of them, the odds are very, very high that there’s at least one, somewhere. And it’s quite plausible that there are, in fact, enough spots in the Universe. ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [June 24, 2023, 8:22pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/53 "2023-06-24T20:22:25Z")
> [@Chronos](#): > > And it’s quite plausible that there are, in fact, enough spots in the Universe. Real question: how is that remotely plausible? Let me break that down into 2 parts, bearing in mind my lack of physics education. 1. Infinite universe. As an approximation of the actual universe that seems fine, since the universe seems to be expanding equally in all directions. But it’s easy to imagine a finite diameter universe, provided the diameter exceeds that of the visible universe. Especially by an order of magnitude or more. But space and mass going on forever seems like an extraordinary claim. 2. Finite universe, but really large. Combinatorial explosions occur in everyday life. As an example (which we’ve discussed before) consider arranging 60 people in 60 chairs for a dinner table (imagine 10 tables with 6 each). Or 60 bricks arranged in different ways to make a 2 step staircase. The number of arrangements (60!) exceeds the number of atoms in the visible universe. So I have serious doubts about anything like Earth2 in this universe (with a human history with similarly named characters), even if its volume exceeds that of the visible universe by 1000. Earth2 in another multiverse? That’s a question I’ll bow out of entirely. Apologies if the answer to my question was implicitly stated above, or if I’ve (likely) misunderstood something. Also, quantum mechanics isn’t especially plausible either (setting aside its confirmed predictive power), so intuitive plausibility may not be the most robust criteria. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 24, 2023, 10:41pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/54 "2023-06-24T22:41:37Z")
If we take a finite universe but a really long amount of time (but still finite) then everything that is happening now will happen again according to [Poincare’s Recurrence Theorem](https://en.wikipedia.org/wiki/Poincar%C3%A9_recurrence_theorem) (granted just a theorem, not proven). The idea is there are only so many arrangements matter can take in a finite universe and over stupidly long periods of time they will have to start repeating previous configurations (so you might do this post again in some exceedingly distant future). I don’t see why this would be different in an infinite universe. Matter cannot arrange itself completely randomly and has a finite number of arrangements it can take (e.g. there has to be a finite number of arrangements a mass the size of earth can take…admittedly a fantastically huge number but still finite). If you go far enough you should start seeing things repeat (eventually). ---
**Author:** ![Kedikat](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@Kedikat](https://boards.straightdope.com/u/Kedikat)\ **Post date:** [June 24, 2023, 11:16pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/55 "2023-06-24T23:16:13Z")
Does each one have to be different? Are there an infinite number of identical universes as well as infinite different ones, Is there some rule to deny infinite identical ones? Do the infinite identical ones have to remain identical going forward? As they are in a specific state. Does it mean they will spawn an identical specific state going forward? Do these infinite universes ever interact? Or do they exist in infinite non interactive spaces? If so, why? How is a universe constrained to come into being somehow separated completely from the infinite others? Do they all exist in a finite space? But do not interact? If no interaction, then how to follow the rule of not interacting? Maybe there are universes existing and coming into existence all over the place. Our universe just has not happened to interact with another one. As far as we know. But if this is the case. I feel they are completely distinct entities. No connection to our own. Our universe extends as far out as its effects can be felt by something. Beyond that, there be Dragons. Unaware of us. Or us of them. Maybe there is some effect of a universe, that sets the boundary of another coming into being. Maybe another universe is even now impinging on ours. But that event is so far away in light speed, that we cannot see it. Keep an eye on that background radiation noise for an uptick? Just my rambling thoughts. ---
**Author:** ![Kedikat](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@Kedikat](https://boards.straightdope.com/u/Kedikat)\ **Post date:** [June 24, 2023, 11:22pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/56 "2023-06-24T23:22:40Z")
I generally feel that when you apply infinite to a thing, it gets out of hand very quickly. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 24, 2023, 11:26pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/57 "2023-06-24T23:26:20Z")
Sure…If you have infinite time and/or space then, no matter how unlikely something is, it will almost certainly happen somewhere / somewhen (assuming it is possible within the physics of that universe). See: Infinite monkeys typing the works of Shakespeare. ---
**Author:** ![Kedikat](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@Kedikat](https://boards.straightdope.com/u/Kedikat)\ **Post date:** [June 24, 2023, 11:36pm UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/58 "2023-06-24T23:36:12Z")
I always think how nice it might be to have infinite Shakespeares at infinite typewriters. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [June 25, 2023, 12:38am UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/59 "2023-06-25T00:38:52Z")
> [@Whack-a-Mole](#): > > (granted just a theorem, not proven) hunh? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 25, 2023, 12:48am UTC](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802/60 "2023-06-25T00:48:29Z")
Has Poincare’s Recurrence Theorem been proven to be true? I might have missed it. [Previous page](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802.md?page=2) [Next page](https://boards.straightdope.com/t/is-it-possible-that-there-are-an-infinite-number-of-universes/985802.md?page=4)