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!
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.
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.
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.)
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.
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 did my math right, it’s also 10e10e115 universe radii or and 10e10e115 proton radii (to the precision given)
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?
The guy who did this literally knew that he was killing all the inhabitants of the “prior” universe.
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.)
As well as others that replied to my post.
Folks, please note the post I was responding to.
- The poster specified a single Universe. No multiverse.
- 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”.
- 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.
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.
Real question: how is that remotely plausible? Let me break that down into 2 parts, bearing in mind my lack of physics education.
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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.
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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.
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 (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).
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.
I generally feel that when you apply infinite to a thing, it gets out of hand very quickly.
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.
I always think how nice it might be to have infinite Shakespeares at infinite typewriters.
hunh?
Has Poincare’s Recurrence Theorem been proven to be true? I might have missed it.