The Order of the Stick: Utterly Dwarfed
The Order of the Stick: Utterly Dwarfed - Coming in December and available for pre-order now
Page 1 of 3 123 LastLast
Results 1 to 30 of 71
  1. - Top - End - #1
    Ettin in the Playground
     
    DrowGuy

    Join Date
    Dec 2015

    Default Are Multiverse Possible In The Real World?

    Because I heard on TV shows (Family Guy) that there are other dimensions from one multiverse to another. So are multiverse possible in the real world?

  2. - Top - End - #2
    Titan in the Playground
     
    Ravens_cry's Avatar

    Join Date
    Sep 2008

    Default Re: Are Multiverse Possible In The Real World?

    A traversable wormhole theoretically could lead to another universe, but that's very very theoretical. As for a multiverse itself being possible, that's essentially the many worlds interpretation, an attempt to explain quantum effects.
    Quote Originally Posted by Calanon View Post
    Raven_Cry's comments often have the effects of a +5 Tome of Understanding

  3. - Top - End - #3
    Bugbear in the Playground
    Join Date
    Jul 2017

    Default Re: Are Multiverse Possible In The Real World?

    Family Guy should not be taken as a serious authority on anything.

    Is there more than our universe? In one sense, absolutely yes; it takes time for light to travel and there's only been so long since the big bang, so there's plenty of stuff that is impossible for us to see. In fact, given the way that the universe is expanding, there's plenty of stuff out there that we will never be able to see. So if you consider the universe to be everything that we could ever see or interact with, we know that there's more than just the universe out there.

    If you mean something deeper, we don't know. Worse, we don't even know how to begin figuring it out. Like some scientists actually believe that every time a random choice happens the universe splits and each possibility becomes its own universe. We don't know whether this is true or not, and even if we could make headway we have no way of interacting with the other universes. So while nothing rules the idea out, neither is there any evidence. When we can't find useful evidence either way for a question, there isn't much we can do about it.

  4. - Top - End - #4
    Dragon in the Playground Moderator
     
    Peelee's Avatar

    Join Date
    Dec 2009
    Location
    Birmingham, AL
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Anymage View Post
    Family Guy should not be taken as a serious authority on anything.
    Especially comedy. HEYO!
    The Mod on the Silver Mountain avatars by the wonderfully talented Cuthalion!

    If anyone has a crayon drawing they would like to put on the Kickstarter Reward Collection Thread, PM me.
    Spoiler: Avatar collection
    Show
    Spoiler: I'm the sun, I'm the sun
    Show
    Spoiler: I can move I can run
    Show
    Spoiler: But you'll never stop me burning
    Show

  5. - Top - End - #5
    Troll in the Playground
     
    Kobold

    Join Date
    May 2009

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Anymage View Post
    Like some scientists actually believe that every time a random choice happens the universe splits and each possibility becomes its own universe. We don't know whether this is true or not, and even if we could make headway we have no way of interacting with the other universes.
    I confess, I don't even understand what the idea means. If there is no way of detecting or interacting with something, then in what sense does it "exist"?
    "None of us likes to be hated, none of us likes to be shunned. A natural result of these conditions is, that we consciously or unconsciously pay more attention to tuning our opinions to our neighbor’s pitch and preserving his approval than we do to examining the opinions searchingly and seeing to it that they are right and sound." - Mark Twain

  6. - Top - End - #6
    Titan in the Playground
     
    ElfRangerGuy

    Join Date
    Aug 2007
    Location
    Imagination Land
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    I confess, I don't even understand what the idea means. If there is no way of detecting or interacting with something, then in what sense does it "exist"?
    There are LOTS of things which he have (or had) no way of detecting or interacting with throughout history, yet they still existed. What's your point?

    Many new things have become observable as technology improves. Some things are still theoretical, like parallel universes, but we might someday find out if they are real or not.
    "Nothing you can't spell will ever work." - Will Rogers

    "What you must learn is that these rules are no different than the rules of a computer system. Some of them can be bent. Others can be broken." - Morpheus, The Matrix

    Quote Originally Posted by Krellen View Post
    Remember, Evil isn't "selfish". It's Evil. "Look out for number one" is a Neutral attitude. Evil looks out for number one while crushing number two.

  7. - Top - End - #7
    Barbarian in the Playground
     
    PaladinGuy

    Join Date
    Sep 2016

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    I confess, I don't even understand what the idea means. If there is no way of detecting or interacting with something, then in what sense does it "exist"?
    On an individual scale there's little way of my detecting or interacting with your next door neighbour. He still exists.
    That doesn't quite work, I could include a request in this post. Fly over.

    So put us both back 1000 years (and ensure that it is transatlantic) so I really can't. He still exists.
    Again still doesn't quite work.

    If multiverse theory is true then an unbiased observer would have to conclude alternative-jayem and this-jayem exist just as much as each other. Of course by even giving them those names I'm demonstrating I'm not an unbiased observer.

    From the point of view of (non one-off) stories, I don't like it.
    Last edited by jayem; 2019-09-28 at 03:19 PM.

  8. - Top - End - #8
    Troll in the Playground
     
    Kobold

    Join Date
    May 2009

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by KillianHawkeye View Post
    There are LOTS of things which he have (or had) no way of detecting or interacting with throughout history, yet they still existed. What's your point?

    Many new things have become observable as technology improves. Some things are still theoretical, like parallel universes, but we might someday find out if they are real or not.
    I didn't say "we have no way of interacting", I said "if there is no way of interacting".

    Nothing in those other-universes can affect (change) anything in this one or vice-versa.

    So tell me, what do words like "real" or "exist" even mean in this context?
    "None of us likes to be hated, none of us likes to be shunned. A natural result of these conditions is, that we consciously or unconsciously pay more attention to tuning our opinions to our neighbor’s pitch and preserving his approval than we do to examining the opinions searchingly and seeing to it that they are right and sound." - Mark Twain

  9. - Top - End - #9
    Bugbear in the Playground
     
    Strigon's Avatar

    Join Date
    Aug 2014
    Location
    Ontario, Canada
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    I didn't say "we have no way of interacting", I said "if there is no way of interacting".

    Nothing in those other-universes can affect (change) anything in this one or vice-versa.

    So tell me, what do words like "real" or "exist" even mean in this context?
    They mean what they always mean. They exist, they are real; whether or not something exists is in no way related to whether or not it's possible for us to interact with it. If there are other universes, then they exist. If this is the only one, then they don't.
    I really don't see how you could argue that existence is dependent on interaction.
    That's all I can think of, at any rate.

    Quote Originally Posted by remetagross View Post
    All hail the mighty Strigon! One only has to ask, and one shall receive.

  10. - Top - End - #10
    Troll in the Playground
     
    Kobold

    Join Date
    May 2009

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Strigon View Post
    They mean what they always mean. They exist, they are real; whether or not something exists is in no way related to whether or not it's possible for us to interact with it. If there are other universes, then they exist. If this is the only one, then they don't.
    I really don't see how you could argue that existence is dependent on interaction.
    I know my friend exists, because I can see her, hear her, talk to her. I know that her imaginary friend Lola doesn't exist, because no one can do those things with her - even my friend freely admits she's invisible.

    Scientists generally say that something exists if they can either detect it (i.e. interact with it, directly or indirectly), or they can infer its existence by observing its effects on something they can detect (like exoplanets, dark matter, HIV, the placebo effect). There is a lot of evidence that these things exist.

    There's a third category, of things they can't presently observe but can speculate about and, potentially, design future experiments that could detect them (until quite recently, exoplanets fell into this category, and black holes). In these cases, while we haven't yet found the evidence, it is possible to describe what it would look like and imagine how we might look for it. It may take generations of work and billions of dollars and digging up half of Switzerland to make the search, but still we can imagine it and talk about how it could work.

    But if I claim the existence of a thing that, by its nature, will always resist detection and cannot possibly produce evidence, it seems to me that that's not a hypothesis (an idea that can be tested), much less a theory. It's just a story we've made up for our own amusement. It's the scientific equivalent of Lola.
    "None of us likes to be hated, none of us likes to be shunned. A natural result of these conditions is, that we consciously or unconsciously pay more attention to tuning our opinions to our neighbor’s pitch and preserving his approval than we do to examining the opinions searchingly and seeing to it that they are right and sound." - Mark Twain

  11. - Top - End - #11
    Barbarian in the Playground
     
    PaladinGuy

    Join Date
    Sep 2016

    Default Re: Are Multiverse Possible In The Real World?

    The thing is it (and related ideas) solves some of the oddities. Most notably Schrodinger cat style ones.

    Without it you kind of have to have some kind of 'magical' phase transition from what is clearly happening on the QM level (simultaneously in multiple states*) to universal-reality.
    Or we need to explain why what is clearly happening on the QM level isn't really happening (variants of hidden-variable theory, which have issues with probabilities).

    It also has the issues of being mostly un-testable. And being (like the time travel version) lousy for interesting series. so I don't particularly like it.
    But that is true with the other options as well.

    *And if not yet with cat sized objects, now non trivial ensembles.

  12. - Top - End - #12
    Bugbear in the Playground
    Join Date
    Jul 2017

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    But if I claim the existence of a thing that, by its nature, will always resist detection and cannot possibly produce evidence, it seems to me that that's not a hypothesis (an idea that can be tested), much less a theory. It's just a story we've made up for our own amusement. It's the scientific equivalent of Lola.
    Scientifically, you're absolutely right. Although I think you're underestimating how much cleverness gets put into finding any way to test between seemingly indistinguishable cases. That's why I covered the basic concept of testability first to OP.

    Philosophically speaking? If our reality is simulated, the server racks have to exist somewhere even if we can never hack ourselves into the "real world" to engage with them. The philosophical meaning may have zero scientific relevance, but so long as nobody tries to confuse the two that doesn't need to be an issue.

  13. - Top - End - #13
    Troll in the Playground
     
    Lvl 2 Expert's Avatar

    Join Date
    Oct 2014
    Location
    Tulips Cheese & Rock&Roll
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Bartmanhomer View Post
    Because I heard on TV shows (Family Guy) that there are other dimensions from one multiverse to another. So are multiverse possible in the real world?
    Short answer, yes. But every form of multiverse theory or alternate dimensions is some interpretation of physics that we can really not test at this point or any point in the foreseeable future. They could exist, but we can't prove it, and they have no effect on our lives.

    Since there are so many versions of the multiverse idea though, I'd like to take a moment to argue against the one I don't like in particular:

    Quote Originally Posted by Ravens_cry View Post
    As for a multiverse itself being possible, that's essentially the many worlds interpretation, an attempt to explain quantum effects.
    Ah, there it is.

    The many/splitting worlds interpretation of quantum mechanics is one of those theoretical solutions to a theoretical problem that creates much, much bigger unsolved mysteries than it purportedly solves.

    The problem is that at a quantum level, the universe seems to contain actual randomness. There are particle interactions that you can only ever predict on a statistical level. You can't tell when a certain radioactive atom is going to decay. You can know its half life, the time within which the chance it decays is 50%, but no matter how many things you measure about the atom, you can't give a better prediction than that. The universe seems to make quantum choices, at a quantum scale things happen for no observable reason at all other than them having a chance to happen.

    Many physicists find this at some level counter intuitive or disturbing. The ever quotable Einstein said "God doesn't play dice". These people have come up with a bunch of ways to explain the apparent randomness without requiring actual randomness. Some might speculate that there is an even smaller scale layer to physics, and if you could measure that you could make sense of the quantum choices we see. But that's boring. The explanation movies go with is "every time a quantum choice is made, the universe splits in two, and both versions continue existing". It's perfect! There is a universe out there exactly like ours except Hitler got a mech suit! Write me that movie!

    Well, okay, Hitler getting a mech suit is not really a quantum decision, and a change like that would realistically cause a lot more changes to the universe as time went on, so their world definitely wouldn't be just like ours (for one, most individuals born after WW2 would be completely different because the exact way and moment their conception happened changed), and technically this wouldn't really be one alternative universe, since there are so many quantum choices being made every second both mech suit Hitler world and our world are actually exponentially expanding clouds of universes rather than single worlds, but if we squint a bit we can ignore all of that and have a mech suit Hitler movie that we can claim is plausible because it's not a fictional setting, it's an alternate universe.

    The reason I don't like the theory, and am in fact tempted to put the word theory between quotation marks, is that it fails to explain where the two universes come from. It wipes its nose all over conservation of mass, conservation of energy and ever increasing enthropy, so basically it tries to explain how our universe works by completely disregarding the most basic rules of the universe. It doesn't even explain where the space/dimensions come from that house these new universes, or how the split universes would move into their separate positions. And sure, technically none of these seemingly super nonsensical breakings of the laws of physics have to be an obstacle. The universe might not know these rules, it does not absolutely have to obey the same rules a child universe does. But these are such basic properties of the universe and to some extend logic itself that I find it rather odd to just assume them away. They throw out everything we know about the world to explain one property that might not even need explaining. Quantum choices are in my opinion not weird and unexplainable enough that we should assume all of physics is basically invalid and time and space continually get created in mind boggling yet ever exponentially expanding quantities just so we can stop thinking about the consequences of our universe possibly knowing true randomness.

    It's fine for movies, if they feel like they really need to explain why there fictional setting is what it is, but it requires some mega extraordinary evidence to be worth being considered anything more than a kinda interesting but overall pretty dumb idea in real life, in my ever so humble opinion.






    Most other forms of multiverse theory are more like "there are universes out there with different fundamental constants. In most of them nuclear fusion doesn't work so they're pretty dead" or "the singularity inside a black hole is actually a new big bang, its own continually expanding universe inside the warped dimensions below the event horizon the hole creates in our universe. But you can't visit it because you would be mega dead if you tried and also frozen in time forever, which is also why we wouldn't have noticed if our universe existed inside a black hole in the next universe up". So, you know, just theoretical physics stuff.
    Last edited by Lvl 2 Expert; 2019-09-29 at 08:33 AM.
    The Hindsight Awards, round 3: Vote for the best movies of 1999.

  14. - Top - End - #14
    Bugbear in the Playground
     
    Strigon's Avatar

    Join Date
    Aug 2014
    Location
    Ontario, Canada
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    I know my friend exists, because I can see her, hear her, talk to her. I know that her imaginary friend Lola doesn't exist, because no one can do those things with her - even my friend freely admits she's invisible.

    Scientists generally say that something exists if they can either detect it (i.e. interact with it, directly or indirectly), or they can infer its existence by observing its effects on something they can detect (like exoplanets, dark matter, HIV, the placebo effect). There is a lot of evidence that these things exist.

    There's a third category, of things they can't presently observe but can speculate about and, potentially, design future experiments that could detect them (until quite recently, exoplanets fell into this category, and black holes). In these cases, while we haven't yet found the evidence, it is possible to describe what it would look like and imagine how we might look for it. It may take generations of work and billions of dollars and digging up half of Switzerland to make the search, but still we can imagine it and talk about how it could work.
    You're pulling a verbal sleight of hand here. You began this discussion by claiming to be confused about what existing means if we can't detect it, but now you're discussing our ability to say such a thing exists. The two are not equivalent.
    You are correct that we can't say it exists or doesn't exist, and possibly never will. But whether or not something exists is independent of whether or not we declare it to.
    In your example, scientists use that particular method of stating whether or not something exists very specifically. They say something exists if there is strong evidence to support that. Likewise, they say something doesn't exist if there is strong evidence to support that. Everything else is said to possibly exist. That's not a third category of existence, it's a statement that it belongs to one or the other, but we don't know which.

    In your Lola example, you're incorrect. We say she doesn't exist because our current scientific model doesn't allow for her, even in theory, and our previous experience with imaginary friends suggests they don't exist. We don't say she doesn't exist because we can't detect her. Even so, a scientist studying her would be careful to specify that it is only likely that she doesn't exist, not that she is outside the bounds of existing or not.
    But if I claim the existence of a thing that, by its nature, will always resist detection and cannot possibly produce evidence, it seems to me that that's not a hypothesis (an idea that can be tested), much less a theory. It's just a story we've made up for our own amusement. It's the scientific equivalent of Lola.
    Then your interpretation is that they don't exist. It's a valid interpretation, one that most people - myself included - share.
    But something doesn't need to be a hypothesis before it can be real.
    The universe - or multiverse in this case - doesn't care what you or I think. As far as it's concerned, the fact that we can't detect or investigate the existence of such a phenomenon is our problem.


    You seem to be under the belief that something can only exist if we're able to say it exists, and something can only not exist if we can prove it doesn't exist, and that everything else belongs to some third classification. That's not the case. Things exist or they don't. We can prove this or not. There is zero correlation between the two.
    That's all I can think of, at any rate.

    Quote Originally Posted by remetagross View Post
    All hail the mighty Strigon! One only has to ask, and one shall receive.

  15. - Top - End - #15
    Barbarian in the Playground
     
    PaladinGuy

    Join Date
    Sep 2016

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Lvl 2 Expert View Post
    Many physicists find this at some level counter intuitive or disturbing. The ever quotable Einstein said "God doesn't play dice". These people have come up with a bunch of ways to explain the apparent randomness without requiring actual randomness. Some might speculate that there is an even smaller scale layer to physics, and if you could measure that you could make sense of the quantum choices we see. But that's boring. The explanation movies go with is "every time a quantum choice is made, the universe splits in two, and both versions continue existing". It's perfect! There is a universe out there exactly like ours except Hitler got a mech suit! Write me that movie!

    Well, okay, Hitler getting a mech suit is not really a quantum decision, and a change like that would realistically cause a lot more changes to the universe as time went on, so their world definitely wouldn't be just like ours (for one, most individuals born after WW2 would be completely different because the exact way and moment their conception happened changed), and technically this wouldn't really be one alternative universe, since there are so many quantum choices being made every second both mech suit Hitler world and our world are actually exponentially expanding clouds of universes rather than single worlds, but if we squint a bit we can ignore all of that and have a mech suit Hitler movie that we can claim is plausible because it's not a fictional setting, it's an alternate universe.
    I think it's worth going into just how many sub universes. Just from the chances of each of Hitlers Cells going cancerous (which is itself a combination of multiple events) you'd have unimaginably more universes being formed (from each existing) universe every second than there are atoms in (each) universe.

    I think that actually gives it a chance back. We almost have to allow some recombination of degenerate universes in such a continuum.

    The [multi-]verse might not know these rules, it does not absolutely have to obey the same rules child universe[s] do. But these are such basic properties of the universe and to some extend logic itself that I find it rather odd to just assume them away.
    Changed some parts that seemed a bit out of perspective.

    The way I'd imagine it (and this is pure imagination), would be to have the multiverse being a super position of the universal eigenstates of rocket-hitler and our-hitler.
    Multi-universal entropy would then have some natural definition that would then make mathematical sense.
    (and yes a few universes would have had entropy going backwards, after all in classical theory there's absolutely no reason why it can't happen in ours, just it would be really stupid to bet on it, but if we are throwing the dice that many times one of them is going to come up 6,6,6,6...)
    Multi-universal Cons of Energy and Mass would then follow, just like an electron doesn't double it's charge when going through the double slit experiment. Although to some extent when talking about the multiverse symmetry of space/time is meaningless so the conservation wouldn't follow directly.

  16. - Top - End - #16
    Ogre in the Playground
     
    Craft (Cheese)'s Avatar

    Join Date
    Jul 2011

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Lvl 2 Expert View Post
    Ah, there it is.

    The many/splitting worlds interpretation of quantum mechanics is one of those theoretical solutions to a theoretical problem that creates much, much bigger unsolved mysteries than it purportedly solves.

    (...)
    Just a couple of thoughts.

    The whole "every time you flip a coin the universe splits in half" thing makes Many-Worlds sound much more radical and amazing than it actually is. QM describes how amplitudes flow through configuration space. Amplitudes already split in copenhagen QM, this is how a particle can form an interference pattern with itself. If two amplitudes flow into the same configuration, they add. The copenhagen interpretation says, that when you take a measurement, all the other configurations go to zero except the one you measured, with probability of a particular configuration being measured equal to the born rule on the amplitude in that configuration.

    Many-Worlds just claims, that the way the universe actually works is that all the particles in the universe are in a single, massive blob of amplitude, moving through a configuration space relating every particle in the universe with every other particle. (Under this interpretation, all particles are always entangled with all other particles to some degree: Quantum independence is just a useful approximation that happens to work locally because QM is linear and unitary.) This gigantic universe-amplitude behaves exactly the way single-particle amplitudes work, that is, it splits and joins and interferes with itself.

    Under Many-Worlds, when you take a measurement, you're just finding out which configuration *your* particles are currently in, along with all the other particles in your amplitude. All Many-Worlds posits is all those configurations we didn't observe, those other "worlds", have their amplitudes unaffected by our measurement. The wavefunction doesn't collapse, those other branches still "exist." This doesn't solve the quantum randomness "problem" at all: You still have no way to predict in advance which configuration you end up in, you can only predict the relative probabilities of each.


    Your concern about conservation of energy is a bit of a red herring: Because we're talking about configuration space, conservation laws are better understood as a restriction on what kinds of configurations amplitude can move into. These restrictions are already baked into QM. Accepting Many-Worlds changes none of our math.

  17. - Top - End - #17
    Troll in the Playground
     
    Kobold

    Join Date
    May 2009

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Strigon View Post
    You're pulling a verbal sleight of hand here. You began this discussion by claiming to be confused about what existing means if we can't detect it, but now you're discussing our ability to say such a thing exists. The two are not equivalent.
    Respectfully, no, there's no sleight of hand. If "exists" doesn't mean "is capable of interacting with other elements of the universe", I honestly don't know what else it can mean.

    Before Einstein's day, the prevalent theory about light was that it propagated as a wave through a mysterious medium called "ether". Then some clever scientists set up an experiment to detect ether, and they got a negative result: ether failed to have the effect it should have had on their experiment. That is to say, it didn't interact.

    That "failed" experiment is what led, some time later, to Einstein's proposal of "special relativity" and the realisation that "ether" was redundant - it had no role to play. And therefore, with some relief, they concluded it doesn't exist.

    Now, I'm sure you can still find people to this day willing to say "we don't know that ether doesn't exist, it might still be there but it just doesn't work the way we thought." But my problem with that position is that ether was only ever inserted into the model to explain something, and when the need for that explanation went away, it was removed from the model. If it really doesn't do what we previously thought, then it's not what we called "ether". Maybe it goes by another name now, like "spacetime" - but that is fundamentally different, and calling it "ether" would just confuse people unnecessarily.

    It's like:
    Alice: "You must have a matter transporter! I know because I was talking to you on the phone just now, and only seconds later you walked in the office!"
    Bob: "No, actually I just have a mobile phone."
    Alice: "Hmph. Well, that doesn't prove you don't have a transporter."

    At this point, I don't think you can defend Alice's reasoning as anything more than wishful thinking.

    What I'm getting at is, what do you mean when you say that something "exists"? Because what I understand by it is that this is a thing that interacts with other things, some of which are at least potentially observable. If it doesn't do that, then it doesn't "exist".
    "None of us likes to be hated, none of us likes to be shunned. A natural result of these conditions is, that we consciously or unconsciously pay more attention to tuning our opinions to our neighbor’s pitch and preserving his approval than we do to examining the opinions searchingly and seeing to it that they are right and sound." - Mark Twain

  18. - Top - End - #18
    Titan in the Playground
     
    ElfRangerGuy

    Join Date
    Aug 2007
    Location
    Imagination Land
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    I don't think we should assume that other universes are not observable. We don't know of any way of observing them at this point, but that doesn't mean we won't figure it out in a hundred years time.
    "Nothing you can't spell will ever work." - Will Rogers

    "What you must learn is that these rules are no different than the rules of a computer system. Some of them can be bent. Others can be broken." - Morpheus, The Matrix

    Quote Originally Posted by Krellen View Post
    Remember, Evil isn't "selfish". It's Evil. "Look out for number one" is a Neutral attitude. Evil looks out for number one while crushing number two.

  19. - Top - End - #19
    Ettin in the Playground
    Join Date
    Dec 2010

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Strigon View Post
    They mean what they always mean. They exist, they are real; whether or not something exists is in no way related to whether or not it's possible for us to interact with it. If there are other universes, then they exist. If this is the only one, then they don't.
    I really don't see how you could argue that existence is dependent on interaction.
    Because if interaction is impossible, then I can posit one hypothesis that 'this other thing exists' and an alternate hypothesis in which 'this other thing doesn't exist', and I can prove that there is no way to know which of the hypotheses is correct. Therefore, at least within the standards of proof that are used for science (which is fundamentally empirical, in that it speaks only to things which can be established using the world as it is as the standard of truth), the existence of that other thing is unfalsifyable. In the case of encountering unfalsifyable elements in a theory or description of the world, the regularization used to prevent biased expansion of assumptions is to favor the description that contains a minimum of unfalsifyable information.

    So - if we can prove that there is no way for something to ever interact with us no matter what, we should act and proceed in the way we would if it did not exist. Additionally, if at any point we have a claim where it would matter that that thing exists or not, then somewhere we know there's a contradiction (because in order to 'matter' - in the sense of changing an outcome or prediction, then there must be a causal consequence of its existence, which means there must be an interaction).

  20. - Top - End - #20
    Barbarian in the Playground
    Join Date
    Aug 2018

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Anymage View Post
    Family Guy should not be taken as a serious authority on anything.
    Most intelligent thing I heard all week.

    Quote Originally Posted by Peelee View Post
    Quote Originally Posted by Anymage View Post
    Family Guy should not be taken as a serious authority on anything.
    Especially comedy. HEYO!
    I take it back. This is.

  21. - Top - End - #21
    Ogre in the Playground
     
    Craft (Cheese)'s Avatar

    Join Date
    Jul 2011

    Default Re: Are Multiverse Possible In The Real World?

    On existence: I genuinely have no idea what it really means for something to "exist" vs. "not exist." I just know it when I see it. The best formulation I can give it is still circular: I believe X exists if the simplest hypothesis that explains my observations requires me to assume X exists.


    Example One: How do I know this website exists? How do I know all of the people in it exist? How do I know the laptop I'm using to access it exists? The only alternative explanation for why I'm here, reading these posts and responding, is that I'm having a remarkably persistent hallucination. And one thing I know from experience as a schizospec person is that hallucinations are never perfectly persistent. My hallucinations usually go away after a few seconds, and the longest one ever lasts is a minute or two. A hallucination lasting *years*? In the absence of extraordinary evidence that i've been hallucinating this entire website, it is simpler to assume that it is real and that it exists.


    Example Two: How do I know that photons exist? The evidence is very overwhelming that they do, or at least that something very very similar to them does. So for them to just not exist at all and the world actually operates under, I dunno, aether physics or something, would require all of the evidence to be a lie. How do I know it's not a lie, when I don't have the ability to perform most of these experiments for myself? Because that would require a massive conspiracy involving the entire scientific community working for some sinister, unknown purpose. That's not impossible, but in the absence of extraordinary evidence, it is simpler to assume that photons exist.


    Example Three: Say a particle leaves earth's atmosphere at near the speed of light, heading down a corridor where it will encounter no other matter until the expansion of the universe brings it out of my light cone and it's gone forever. I will never be able to interact with this particle ever again even in principle. So does it still exist?

    Well, all of my models of how the universe works is that things don't disappear when I close my eyes. To suppose the particle stops existing, would require me to modify my theory such that things suddenly blink out of existence once I'm no longer able to detect or interact with them. It's an extra term that, as far as I can tell, gives me no additional predictive power (it's also very suspicious in other ways: For example that it'd have to be a nonlocal effect). So, I remove it, and thus the simplest hypothesis is that the particle exists.


    So, I have this theory of fundamental physics with overwhelming evidential support. As a side effect of this theory in its simplest formulation, there are all these other universes out there that I can never, not even in principle with some discovery of new physics (since that would just change the shape of the configuration space), interact with or detect in any way. Do these other universes exist?

    Well... I'd say, yes, obviously. To say that they don't exist would mean applying an extra term to the theory, one that says that any universe you can't see, doesn't exist. There is no (and indeed, never can be) evidence that this actually happens. Therefore, the simplest hypothesis is to assume these other universes exist.

    (Of course, there is evidence that could make me disbelieve in these universes: A better theory to come out that explains more phenomena with greater accuracy, but which doesn't predict all of these undetectable extra universes as a side effect of the math.)

  22. - Top - End - #22
    Ettin in the Playground
    Join Date
    Dec 2010

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Craft (Cheese) View Post
    So, I have this theory of fundamental physics with overwhelming evidential support. As a side effect of this theory in its simplest formulation, there are all these other universes out there that I can never, not even in principle with some discovery of new physics (since that would just change the shape of the configuration space), interact with or detect in any way. Do these other universes exist?

    Well... I'd say, yes, obviously. To say that they don't exist would mean applying an extra term to the theory, one that says that any universe you can't see, doesn't exist. There is no (and indeed, never can be) evidence that this actually happens. Therefore, the simplest hypothesis is to assume these other universes exist.

    (Of course, there is evidence that could make me disbelieve in these universes: A better theory to come out that explains more phenomena with greater accuracy, but which doesn't predict all of these undetectable extra universes as a side effect of the math.)
    The tricky thing is, there's what the math of that theory says, and then there's the interpretation of that math in terms of physical reality. You can take the Many Worlds interpretation of QM, or take a probabilistic interpretation of QM, or just say that the amplitudes are the real thing and everything else is just philosophy, and the math doesn't change - therefore, the predictions don't change, and as a result you can't discriminate between those hypotheses.

    You don't actually need to add a new term to QM to interpret it in a way that doesn't result in alternate universes.

    Since the predictions don't change when you change the interpretation, it sort of implies that the fuss about interpretation is a distinction without a difference - that we're insisting that some term should matter because of our (classical) physical intuition that stuff like objects are the kinds of things that can be real and exist physically, whereas things like complex probabilities have to be 'virtual' and refer to some actual underlying reality.

    Then we get in trouble trying to use the interpretation to apply logic to how things should work, rather than the math (e.g. reading Many Worlds as 'the universe splits with each decision' rather than 'the actual phase space volume associated with the degrees of freedom of a volume of 3d space of linear dimension N is e^N, not N^3' which is closer to what you get directly from the math.

  23. - Top - End - #23
    Ogre in the Playground
     
    Devil

    Join Date
    Jun 2005

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Strigon View Post
    They mean what they always mean.
    As near as I can tell, saying that "there is" some "real" thing that "exists" normally means that said thing interacts with us, whether directly or indirectly. If you deny that, then what's your alternate theory as to what those terms signify? What's the difference between something that exists and something that doesn't exist?
    Spoiler
    Show

  24. - Top - End - #24
    Barbarian in the Playground
     
    PaladinGuy

    Join Date
    Sep 2016

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Devils_Advocate View Post
    As near as I can tell, saying that "there is" some "real" thing that "exists" normally means that said thing interacts with us, whether directly or indirectly. If you deny that, then what's your alternate theory as to what those terms signify? What's the difference between something that exists and something that doesn't exist?
    But "if many-worlds theory" is true, then by that definition, the effectively unanimous conclusion is that this universe doesn't exist.

    I'm going to say that existence is a fundamental concept. Things exist if they exist. What is is. Things that don't exist don't exist. If there are many worlds then each one exists. Each thing that there isn't doesn't exist.

    If something interacts then it exists. Though that's probably a bit of a reckless statement (does entropy exist?)
    Contra-positively if something doesn't exist then it doesn't interact.

    There are vastly more things that could exist than do exist. Where appropriate Occam's razor is a good thing to apply. There is almost certainly not an invisible undetectable tea pot in a 5km orbit round Mars (though I hope one of the missions has put a detectable one there) if there is one though, it exists (in this case we don't lose anything for being wrong).
    An invisible undetectable tea pot above England that is responsible for our cravings but at a level that was also consistent with history and chance is also unlikely but has consequences.

  25. - Top - End - #25
    Troll in the Playground
     
    Kobold

    Join Date
    May 2009

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by jayem View Post
    But "if many-worlds theory" is true, then by that definition, the effectively unanimous conclusion is that this universe doesn't exist.
    If you're silly enough to give the vote to effectively infinite numbers of people who don't exist, you deserve to lose.

    I'm going to say that existence is a fundamental concept. Things exist if they exist. What is is. Things that don't exist don't exist. If there are many worlds then each one exists. Each thing that there isn't doesn't exist.
    Umm... That's just a series of tautologies. That's... not super clarifying.

    There are vastly more things that could exist than do exist.
    Whoa whoa whoa, what do you mean by "could exist"? If you mean to suggest that their existence would be compatible with the existence of everything that does exist, that's clearly not true. (Because if they existed they would interact with, and thus change, the things that do exist, and therefore the real things would be different.)

    If you limit it to the things we know to exist, then OK, but only because of the vastness of our ignorance.

    An invisible undetectable tea pot above England that is responsible for our cravings but at a level that was also consistent with history and chance is also unlikely but has consequences.
    If it's "responsible" for that, then it's not undetectable: you can deduce its presence and its movements, if any, by observing patterns of demand for tea. If it interacts, it's detectable. If it doesn't, then it can't be responsible for anything.
    "None of us likes to be hated, none of us likes to be shunned. A natural result of these conditions is, that we consciously or unconsciously pay more attention to tuning our opinions to our neighbor’s pitch and preserving his approval than we do to examining the opinions searchingly and seeing to it that they are right and sound." - Mark Twain

  26. - Top - End - #26
    Troll in the Playground
    Join Date
    Jan 2007

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    Umm... That's just a series of tautologies. That's... not super clarifying.
    Because existence is an intrinsic quality without any proper definition. It cannot be more strictly defined, since it would require some other ideas we would base our definition on. In a similar manner there is no definition of a set in mathematics, since everything there is derived from the idea of a set.

    Our inability of unequivocally stating what is or is not real is the reason one cannot disprove a solipsist.

    Quote Originally Posted by veti View Post
    Whoa whoa whoa, what do you mean by "could exist"? If you mean to suggest that their existence would be compatible with the existence of everything that does exist, that's clearly not true. (Because if they existed they would interact with, and thus change, the things that do exist, and therefore the real things would be different.)
    There is no reason to assume that all existing things have to interact. Where did you get that notion from? Let us take the totality of existence. Since there is nothing else out there, it does not interact with anything.

    I can understand that Occam's Razor is a reasonable assumption on which one can base their point of view, but it is an assumption - not a strictly provable law. Therefore lack of interaction does not in principle prohibit things from existing. We just have no reason to care about things we have no way of contacting.
    In a war it doesn't matter who's right, only who's left.

  27. - Top - End - #27
    Troll in the Playground
     
    Lord Torath's Avatar

    Join Date
    Aug 2011
    Location
    Sharangar's Revenge
    Gender
    Male

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by Radar View Post
    There is no reason to assume that all existing things have to interact.
    Example: In a few billion years, the expansion rate of the universe will be such that no galaxy cluster will be able to interact with any other galaxy cluster. The space between them will be expanding at a rate faster than the speed of light. There will be no interactions between them. At all. Does that mean that at that point, all those other galaxies spontaneously cease to exist? Of course not.
    Warhammer 40,000 Campaign Skirmish Game: Warpstrike
    My Spelljammer stuff (including an orbit tracker), 2E AD&D spreadsheet, and Vault of the Drow maps are available in my Dropbox. Feel free to use or not use it as you see fit!
    Thri-Kreen Ranger/Psionicist by me, based off of Rich's A Monster for Every Season

  28. - Top - End - #28
    Ettin in the Playground
    Join Date
    Dec 2010

    Default Re: Are Multiverse Possible In The Real World?

    There is no reason to assume that all existing things have to interact. Where did you get that notion from? Let us take the totality of existence. Since there is nothing else out there, it does not interact with anything.

    I can understand that Occam's Razor is a reasonable assumption on which one can base their point of view, but it is an assumption - not a strictly provable law. Therefore lack of interaction does not in principle prohibit things from existing. We just have no reason to care about things we have no way of contacting.[/QUOTE]

    It becomes an issue when elements are injected into a theory or model of reality, which have no consequence. The reason it is an issue is that if something can be injected without consequence, then it is essentially arbitrary and I can choose it to be whatever I want. So if someone tells me 'there is this thing which cannot possibly interact with us, and yet at the same time it is essential that you accept that it exists in order to explain this other thing (which we can interact with)', then I know a logical error has been committed somewhere.

    If you look at QM and say 'if we accept QM, we have to accept that other universes exist' and 'QM predicts that there would be no way for those universes to interact with us' and 'we have to accept QM, because it predicts physical and material properties better than anything else', then a logical error has been committed. QM's predictions of physical and material properties cannot possibly hinge on the existence of other universes, because if it did, then that would imply that there was some kind of interaction between those other universes and those physical and material properties - yet the math of QM itself says there should be no such interaction. So any claim about other universes using QM as a basis is, essentially, an arbitrary choice reflecting some bias of the claimant, rather than a prediction.

    Or to put it another way, by adding interpretation to the math, one over-specifies the theory. However, since the interpretation is basically inert, it also can't be proven or disproven - but that means that its essentially irrelevant, at least within the evidentiary framework used to justify the theory in the first place.

    Quote Originally Posted by Lord Torath View Post
    Example: In a few billion years, the expansion rate of the universe will be such that no galaxy cluster will be able to interact with any other galaxy cluster. The space between them will be expanding at a rate faster than the speed of light. There will be no interactions between them. At all. Does that mean that at that point, all those other galaxies spontaneously cease to exist? Of course not.
    If we take the example of galaxy clusters, they're still causally coupled over the extent of the thing we're talking about - take one particle from one of those galaxy clusters and make a universe in which that atom never existed, and the timeline of every other bit of matter in the universe that ever intersected the light cone of that atom would also be modified.

    Therefore, even if you're currently at a time in which you're forever more outside of that particles's light cone, you can still in principle at least distinguish between a universe with that particle and a universe without that particle, by virtue of the interactions it had previously (whose consequences have a light cone which you are still in).

  29. - Top - End - #29
    Troll in the Playground
    Join Date
    Jan 2007

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by NichG View Post
    It becomes an issue when elements are injected into a theory or model of reality, which have no consequence. The reason it is an issue is that if something can be injected without consequence, then it is essentially arbitrary and I can choose it to be whatever I want. So if someone tells me 'there is this thing which cannot possibly interact with us, and yet at the same time it is essential that you accept that it exists in order to explain this other thing (which we can interact with)', then I know a logical error has been committed somewhere.

    If you look at QM and say 'if we accept QM, we have to accept that other universes exist' and 'QM predicts that there would be no way for those universes to interact with us' and 'we have to accept QM, because it predicts physical and material properties better than anything else', then a logical error has been committed. QM's predictions of physical and material properties cannot possibly hinge on the existence of other universes, because if it did, then that would imply that there was some kind of interaction between those other universes and those physical and material properties - yet the math of QM itself says there should be no such interaction. So any claim about other universes using QM as a basis is, essentially, an arbitrary choice reflecting some bias of the claimant, rather than a prediction.

    Or to put it another way, by adding interpretation to the math, one over-specifies the theory. However, since the interpretation is basically inert, it also can't be proven or disproven - but that means that its essentially irrelevant, at least within the evidentiary framework used to justify the theory in the first place.
    I fully agree here, since there is a vast difference between a philosophical could possibly exist (which I was considering) and making something an integral part of a physical theory. I was just arguing that on the most basic level we cannot disprove existence of things that do not interact with us and interaction is not a strict requirement for existence.
    In a war it doesn't matter who's right, only who's left.

  30. - Top - End - #30
    Barbarian in the Playground
     
    PaladinGuy

    Join Date
    Sep 2016

    Default Re: Are Multiverse Possible In The Real World?

    Quote Originally Posted by veti View Post
    If you're silly enough to give the vote to effectively infinite numbers of people who don't exist, you deserve to lose.
    That is circular reasoning with begging the question. Besides why should I care what some figmant of my imagination says doesn't exist.
    Yes if they don't exist they don't exist.

    Umm... That's just a series of tautologies. That's... not super clarifying.
    Yes it's also circular reasoning, but as Radar says that's the point.

    (Because if they existed they would interact with, and thus change, the things that do exist, and therefore the real things would be different.
    That is also circular reasoning.
    Provably existing things are almost certainly a subset of interacting things.

    Assuming that there are no existing non-interacting is an assumption. If many-worlds theory is true then they have to exist and we have a counter example, if many-worlds theory is false but in an interesting way (cref Maxwell's idlers) then they don't have to exist, if many-worlds theory is false in a boring way then they don't have to exist.

    In practice without some additional as yet unimaginable interaction, we have no support at all (other than wishy washy prettiness) for the many-worlds hypothesis (and similar) and worse nothing we can realistically do to disprove it. NichG is quite right.

    On the other hand:

    Non-(necessarily)-interacting is the simpler version, why run the risk of demanding additional entities (interactions) and making a host of assumptions about their nature if we don't need to. Maybe there's an attractive force between similar universes so million to one chances actually happen on one in a billion universes. Almost certainly that's total bollocks, and me adding complicating bollocks so they now interact shouldn't make it more likely (It does make it more testable, which is important).

    If it provides a useful shortcut for theorums then why not build on it, when we reach a contradiction and disprove it we'll then have to explain every result it did explain, and we'll have to treat every result based off it with caution but we should be checking our results anyway. If it doesn't provide a useful shortcut, then even if it were true, why are you using it.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •