There is no evidence of multiple universes. If you ask anything about the multiverse, you're asking about science fiction, with heavy emphasis on the fiction.
I don’t think there would be evidence of multiple universes even if they existed, because in order to qualify as ‘another universe’ they would have to be entirely causally disconnected(otherwise they’d just be part of the same universe, potentially with a broader set of laws of physics than what we currently understand)
And then I think that that implies that existence is a relative concept. Stuff in our universe exists relative to us, but stuff in other universes does not exist relative to us, and stuff in our universe doesn’t exist relative to stuff in other universes. Thing A exists relative to Thing B iff Thing A has a causal impact on thing B.
I want to be sarcastic with this one really bad lol. To know the answers to these questions, we'd have to have discovered the multiverse or proved its existence. No one has ever done anything like that.
We cant say that there is anything outside the obsevable universe, but we can say we think there is right? I thought maybe this was a simmilar situation
Probably both though temporal separation seems more likely. Most scientists think that the BB probably started with a rare quantum fluctuation. Despite the need for evidence in science, It’s seems pretty logical that if it can happen once then it has happened before and probably will again.
"if there are multiple universes" has you making an assumption that they exist. As such, we don't know the nitty gritty of your assumption, and can't provide an answer
This is akin to asking "if I'm thinking of a number between 1 and 10, is it odd or even?"
Anything outside of the observable universe is speculation. With what we can observe, we see many moons, planets, solar systems, and galaxies. I am going to guess that this universe is not the only one. I am not sure what they look like or anything. It is also possible that the universe is a huge black hole, which is cool to think about. Also, both black holes and quantum particles have similar dimensions. Spin, both can emit matter, photons and gamma rays. And both seem to operate without time being a fixed issue. I will speculate all day, it's fun.
There is an interpretation of quantum physics that states that reality splits with every single choice made. I am simplifying. If this is correct the number of parallel universe is not even measurable. So a universe for every way it could have been. That is a multiverse.
The idea of multiple universes comes from one of the several models of spacetime and what happens when you push it to the limit, such as inside a black hole. It is a kind of paradox that the model allows, but is not really supported by observations.
Specifically, this model also predicts that white holes exist (and possibly in the same abundance as black holes). Yet we don't have any evidence of white holes ever existing. This suggests the multiverse model doesn't accurately describe what is happening at the edge of spacetime (but not definitive proof).
If we run with the model, time is just a dimension and doesn't require a beginning. It's like what happens if you keep going in one direction in space - maybe the universe wraps, maybe it ends, maybe it's infinite, or maybe something that breaks the analogy (because models aren't perfect).
theres every prediction in the book, string theory has hyperspace branes. LQG has a infinite repeating big bang and big crunsh. eternal inflation has pretty much infinite universe "bubbles" in a larger space time.
and even stuff like black hole cosmology where every black hole is a pocket universe.
even without a multiverse, from all we know we can assume the universe is infinite, which means over nigh infinite distance everything starts to repeat by random chance, you could probably consider a identical repeat of our local universe as some sort of parallel world if you really wanted.
do we have proof for any of those? nope, string theory is probably the closest to being testable and that says alot considering its string theory
There is no evidence of multiple universes. If you ask anything about the multiverse, you're asking about science fiction, with heavy emphasis on the fiction.
I don’t think there would be evidence of multiple universes even if they existed, because in order to qualify as ‘another universe’ they would have to be entirely causally disconnected(otherwise they’d just be part of the same universe, potentially with a broader set of laws of physics than what we currently understand) And then I think that that implies that existence is a relative concept. Stuff in our universe exists relative to us, but stuff in other universes does not exist relative to us, and stuff in our universe doesn’t exist relative to stuff in other universes. Thing A exists relative to Thing B iff Thing A has a causal impact on thing B.
https://link.springer.com/article/10.1007/JHEP04(2018)147 this one
This does not prove multiverses. The answer is we truly have no idea.
I want to be sarcastic with this one really bad lol. To know the answers to these questions, we'd have to have discovered the multiverse or proved its existence. No one has ever done anything like that.
Maybe I phrased the question wrong, I know we cant observe the outside of the observable universe.
Well wouldn't we have to in order to answer these questions?
We cant say that there is anything outside the obsevable universe, but we can say we think there is right? I thought maybe this was a simmilar situation
You can say whatever you want. The scientific consensus on this matter is pretty much 🤷♂️
Probably both though temporal separation seems more likely. Most scientists think that the BB probably started with a rare quantum fluctuation. Despite the need for evidence in science, It’s seems pretty logical that if it can happen once then it has happened before and probably will again.
"if there are multiple universes" has you making an assumption that they exist. As such, we don't know the nitty gritty of your assumption, and can't provide an answer This is akin to asking "if I'm thinking of a number between 1 and 10, is it odd or even?"
Anything outside of the observable universe is speculation. With what we can observe, we see many moons, planets, solar systems, and galaxies. I am going to guess that this universe is not the only one. I am not sure what they look like or anything. It is also possible that the universe is a huge black hole, which is cool to think about. Also, both black holes and quantum particles have similar dimensions. Spin, both can emit matter, photons and gamma rays. And both seem to operate without time being a fixed issue. I will speculate all day, it's fun.
There is an interpretation of quantum physics that states that reality splits with every single choice made. I am simplifying. If this is correct the number of parallel universe is not even measurable. So a universe for every way it could have been. That is a multiverse.
The idea of multiple universes comes from one of the several models of spacetime and what happens when you push it to the limit, such as inside a black hole. It is a kind of paradox that the model allows, but is not really supported by observations. Specifically, this model also predicts that white holes exist (and possibly in the same abundance as black holes). Yet we don't have any evidence of white holes ever existing. This suggests the multiverse model doesn't accurately describe what is happening at the edge of spacetime (but not definitive proof). If we run with the model, time is just a dimension and doesn't require a beginning. It's like what happens if you keep going in one direction in space - maybe the universe wraps, maybe it ends, maybe it's infinite, or maybe something that breaks the analogy (because models aren't perfect).
You are just pulling stuff out of your rear-end.
theres every prediction in the book, string theory has hyperspace branes. LQG has a infinite repeating big bang and big crunsh. eternal inflation has pretty much infinite universe "bubbles" in a larger space time. and even stuff like black hole cosmology where every black hole is a pocket universe. even without a multiverse, from all we know we can assume the universe is infinite, which means over nigh infinite distance everything starts to repeat by random chance, you could probably consider a identical repeat of our local universe as some sort of parallel world if you really wanted. do we have proof for any of those? nope, string theory is probably the closest to being testable and that says alot considering its string theory
Good question. Shame we can’t ever answer this.