Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

If M-Theory Is True, All Possible Realities Exist?

  1. Feb 24, 2007 #1
    If M-Theory Is True, All Possible Realities Exist??

    M theory predicts that there are an infinite amount of universes that make up the multiverse. Some universes have a completely different starting point and thus different laws of physics. This would mean their forms of matter will be far different forms of matter from our universe. Whatever can be done and rearranged mathematically is possible. Wouldn't this mean every possible realities exist? Everything the human mind can imagine would be possible because there are certain mathematical and chemical arrangements for everything you can imagine, including fiction.

    Take for example the film The Matrix. Obviously in our universe it is fiction because the mathematical arrangements of our universe is different than that of the universe within that film. However, there are an infinite amount of possible universes just from our big bang alone. Most likely the universe described in the film is exactly the same until say 1999......and then the movie's reality takes over. There are certain mathematical arrangements of matter and energy that would lead to exactly the conditions in the film. We can even imagine the DNAs of the actors being identical to a possible arrangement of organic matter in at least one or more of the other possible universes. At the same time the organic matter can be arranged differently so that you and I replace the actors. At the same time perhaps everything that happen in our universe happens except to an intelligent dinosaur species.

    In other words every possible reality that can be imagined by the human mind (or any mind for that matter) exists in one of the alternatives. It shouldn't matter on how similar and different the universes are, some physicists say that there are other universes exactly like this one only you or I was never born.

    Do you guys understand what I'm saying? If so, isn't this what M-theory basically predicts?
  2. jcsd
  3. Feb 24, 2007 #2
    I am not sure but this doesn't seem formal or rigorous enough to validate it's emergence in this forum, however, I rarely post here (because this forum deals largely with mathematical content that is years beyond me), so I could be incorrect.

    As for The Matrix, that movie really just took Cartesian Dualism and Bereklian, subjetive Idealism and packed it into a blockbuster film.
  4. Feb 25, 2007 #3
    Not just The Matrix though, any fictional universe should exist because matter and energy arranged in a certain way should produce that universe. With mathematics governing the different universes, anything and everything should be possible.
  5. Feb 25, 2007 #4
    This is going to derail the topic but you speak about mathematics as though it is an objective aspect of nature and exists independent of human mind. Also, you are not grasping the primary objective of M-Theory. It's 'supposed' to function as a unifier of the five superstring theories. Paralell universes, I think, emerge as a consequence of the mathematics and has no physical basis. I honestly think M-Theory is too mathematically abstract, rigorous and esoteric to grasp it's full implications, without knowing a lot of high level maths and physics.

    I really don't see why people spend so much time on these pop-sci theories that have really, no falsifiability nor has it made any empirical predictions (if any such predictions are possible).

    There may be some M-Theory experts here (or string theory), which can probably give you a much better response than I have.
  6. Feb 26, 2007 #5


    User Avatar
    Science Advisor
    Gold Member

    Irrelevant. Imaginary universes have no observable consequences in our universe. That is philosophy, not science.
  7. Feb 26, 2007 #6
    I would like to note the following.

    There are to kinds of common theorectical construcs wich leads to the idea of "multiverse", but they are diferent.

    In one hand we have the Everet´s "many worlds" interpretation of quantum mechanics.There every time a quantum function is colapsed you have a new world for any of the posibles values of the measurement.

    In string theory the thing is diferent. You have one theory which admist many vacuums, and, up to now, not a very good guide to chose a particular one. Infact that situation is not exclusive of string theory. Gauge theories also hae sometimes that feature. Inspired in that weinberg sugeested that the actual vacuume was a superposition of all the possible vacuums. All the vacuums had a 0 cosmological constant in all but a limited region of space. If you superpose al them you get an ubicuous small cosmological constant. The problem is that gague theories have not engought vacua for the theorie match the observed values of posible inhomogenities.

    String theory has many more vacuums compatible with the MSSM and could use these mechanism. But that´s all. You don´t have many worlds/univereses, you have just one world with a vacuum which is a superposition of many, but a single universe builded around that vacuum.

    Don´t ask me too many details that i am still studiying the insides of the idea of flux compactifications which is behind these viewpoint.
  8. Feb 26, 2007 #7
    this theory contradicts itself. You say that there are some universes where physics and stuff like that are way different. The only reason you can say that there might be infinite universes is because we have an idea of what infinity is. If there was no such thing as infinity, you cant say that there is infinite realities.

    if infinite realities exist, then there are realities where there is no such thing as infinity, meaning the number of universes is finite.

    this is a major paradox: If there are infinite universes, then the number of universes is finite.

    So, m-theory contradicts itself, and all possible realities do not exist.

    also, this point really does override any speculation about infinite universes. If anythign happening in a different universe will never have any observable consequence in our universe, why would we care? All science is concerned with our observable universe.
    Last edited: Feb 26, 2007
  9. Feb 26, 2007 #8
    You seem to think that our minds are somehow intimately connected with the fabric of the cosmos. If we're nothing but animals (and what reasons do you have for supposing that life as we know it was essential for the existence of the universe? If it would be left unobserved, would you still be asking these questions?), then it is all a result of our proactive imagination and has nothing to do with what is happening in space, then whatever we imagine is just a function of our overdeveloped big-brains and not something that necessarily exists as a "potential" within the multiverse or wherever else.

    Now, if, as you say, "everything the human mind can imagine would be possible" then that contradicts itself, because then, in fact, stuff that is absurd to begin with would also be possible (such as the existence of nothing rather than something), or the nonexistence of logic which you use to infer your conclusions or the nonexistence of the very mind which purportedly assumes that everything is possible.

    Many things that are mathematically sound exist only on paper, and M-Theory (which no one know what it is so far) exists only on paper.

    Besides, the existence of infinite universes has more to do with the interpretations of Quantum Mechanics (Copenhagen & Everest) and not with M-Theory per se. Last I heard, M theory postulated the existence of an 11-dimensional multiverse - does that read like infinity to you? M-Theory is an extension of String (superstring) theories, the last revolution that took place before it came to a dead-end (Loop Quantum Gravity, on the other hand, has no need for extra dimensions or supersymmetry at all, at least from the Rovelli book I read a while ago)
    Last edited: Feb 26, 2007
  10. Feb 28, 2007 #9

    Why is imaginary universe different from imaginary number?
  11. Feb 28, 2007 #10
    Imaginary universes require a physical, material existence while an imaginary number functions as an emergent property of particular formal logic systems. Also, an imaginary universe requires an overwhelming amount of physical and mathematical description as well as some empirical support, I would think.

    I think, however, it is a non sequitur to conclude that because both concepts use the word 'imaginary,' that they are analagous.

    To clarify, when you are discussing the term 'imaginary number' are you referring to a complex number in the form of [tex]z=x+iy[/tex], where [tex]x[/tex] and [tex]y[/tex] are real numbers and [tex]i[/tex], is an imaginary unit, [tex]i^2=-1[/tex]. Complex Analysis is a course which would give you a formal, rigorous understanding of these mathematical objects, I would think (something I will take soon, I hope).

    Or are you referring to a purely imaginary number, in which a complex number, [tex]z[/tex], has no real part such that [tex]R [z]=0[/tex]?

    However, I am still an undergraduate student and my understanding of maths is still very incomplete, so hopefully I haven't botched the explanation.
    Last edited: Feb 28, 2007
  12. Feb 28, 2007 #11
    Thanks for the reply cP.

    Chronos objects to the idea of an imaginary universe because "Imaginary universes have no observable consequences in our universe." I am not sure this has been completely determined. An analogy may be in the classical objection to black hole singularities....we classically cannot observe what is beyond the horizon. However Hawking has calculated that black holes do radiate, because of quantum effects, which seems to imply that whatever is behind the horizon (its entropy, for instance, which would depend on its surface area, or, I think, on its history of what has fallen into it) does in fact have an observable consequence.

    Of course this analogy could be poorly formed. Still, I am left wondering if imaginary numbers can give us a clue. Like time, imaginary numbers are an indicator of rotation. If there are imaginary universes, as in the title of this thread, it seems likely they would occupy alternate times. Of course as 3-space 1-time critters, we cannot look at two or more times at a time. The very words forbid it. Looking at a time is necessarily not to look at two or more times.

    However, there are some unusual quantum behaviors, which are observable, and which can only be described mathematically using imaginary numbers. Should we not look at these as an indication, like Hawking radiation for black holes, that what is beyond our ability to see can still have an observable effect upon what we do see? In other words, should we not conclude that imaginary universes, which we cannot observe directly, may still have effects upon things we can observe, from which we can deduce the conditions which are hidden from our view?

    Hawking radiation, Unruh radiation, and virtual particals all seem to me to suggest there is something there which we cannot see. Dark energy? Dark matter? Maybe, in our calculation of how much matter is available to affect things like galactic rotation, we should include all the possible contributions from visable moving objects which are themselves affected by Unruh radiation? In other words, we would have to sum all the Unruh radiation effects on all the particals which, from our perspective, appear to be moving?

    Distant objects, such as those we observe when trying to measure the expansion of the universe, are clearly moving very fast and so from our point of view would have to be experiencing more Unruh gravitation than we can see directly.

    Oh well. Just idle speculation. I am prone to that, since I want to try to see, and yet I still do not know how to calculate.


  13. Mar 1, 2007 #12
    RH are you speculating an infinity of times ?

    as though in an infinity of universi some could operate under a different measurement of timespeed . In some it would be slow, in others fast, like how our universe has an upper speed limit of c but in others it may not ?

    would the lower limit then be a universe where time stands still and if that were possible would that limit it's finiteness as it wouldn't be expanding ?

    does time then run backward in a shrinking universe ?

    i guess what i'd like to know is, is all of everything happening now ? the universe refreshing and reconstituing itself into different combinations happens at every micro increment of time such that there is no future or past only now and does that apply to a multiverse scenario ?

    ok I'll go quietly back to my hole now
  14. Mar 1, 2007 #13

    Sorry couldn't resist.

    Actually, I can't reply right now, but I want to. Don't feel well today.

    Yes, infinite times.

    Of course, light speed can vary under conditions in our universe, even in the laboratory. But I usually think of the SOL as a unit.....makes it easier to think of quantum geometry.

    if time stood still, would it still be time?

    No, I don't think it would be necessary to say time could run backward in a shrinking universe. If it did, wouldn't the universe be expanding, then?

    What do you mean by "now?" Now isn't even a useful concept with-in our own galaxy.

    These are hard things to think about and I have a headache today. Our language doesn't help. It is firmly rooted in the idea of three dimensions of space and one of time. Maybe math is better. Physics is also stated firmly in a one-time scheme.

    But basically I think you are trending in the right direction.

    Sorry, but I really have to go have a lie down.

    Causality is at risk in these waters.


  15. Mar 3, 2007 #14
    cheers RH

    I just now had another thought :wink:

    'now' is the present as opposed to the past which was 'now' that has been and the future 'now' that hasn't occured yet

    'now' is the moment which everything is happening in

    'now' is what is currently happening to the remnants of a star that went supernova millions of years ago but whose light is still reaching us

    if you froze time/motion in this universe surely that wouldn't neccessarily mean time would be frozen in another universe in a multiversal scenario ?
  16. Mar 3, 2007 #15


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2018 Award

    This thread has taken on a nasty, over-speculative bent (which, I think, I could smell from a mile away with that topic). Please note that even in THIS sub-forum, the global PF Guidelines on over-speculative post still APPLIES. Since the nature of the subject being discussed in here tends to be less certain than other areas, we do try to allow some degree of it, but they must STILL be based on a foundation on peer-reviewed, or at the very least, arxiv-posted articles (the few areas in which such a venue is common). In other words, you just can't make things as you go along. If it cannot be given a valid citation, then it doesn't belong in here.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook