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Restart The Big Bang

  1. Nov 3, 2005 #1
    Lets say we restarted the big bang, what are the chances that we would get different physical laws?

    Or is this one of those unaswerable questions?
     
  2. jcsd
  3. Nov 3, 2005 #2

    Danger

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    I think that the physical laws (or at least constants) that we have are completely arbitrary. Getting the same ones again would be unlikely.
     
  4. Nov 3, 2005 #3

    Pengwuino

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    I think the constants are completely arbitrary but I wouldn't think that the physical laws could change...
     
  5. Nov 3, 2005 #4

    SpaceTiger

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    Certainly unanswerable right now. Couldn't say if it will be answerable in the future.
     
  6. Nov 3, 2005 #5
    Yeah, thats the word I was looking for...arbitrary, and I wanted to know about laws specificly?

    Why do you think they wouldnt change Pengwuino?
     
  7. Nov 3, 2005 #6

    Pengwuino

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    Well all laws seem to have a mathematical connection that can seemingly be all reduced to simple addition adn subtraction when you really get down to it. Can you really have "things" in this new universe that won't end up being 1's and 2's and 3's and such? I don't see why they would or even could change...
     
  8. Nov 4, 2005 #7

    Chronos

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    I have great difficulty imagining a 'universe' where physical laws [and related constants] were not exquisitely fine tuned. It would otherwise self destruct, or be incredibly boring.
     
  9. Nov 4, 2005 #8

    hellfire

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    As far as I know it is widely believed that the early universe underwent some phase transitions breaking the symmetry of the ground state when decreasing its temperature. For causally disconnected regions this may lead to arbitrarily different results with different interactions and different masses of carrier bosons in different “domains” of our universe. This is based on the physics of the standard model. Whether such thing actually took place is unknown but there are lots of models and papers about this (see e.g. the work of Andrei Linde). My guess is that you would get statistically the same universe on very large scales when restarting the big-bang.
     
  10. Nov 4, 2005 #9

    Astronuc

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    I believe that is an unaswerable question, because one does not know the initial conditions, or conditions t<0, which itself is an interesting concept to get one's mind around.

    The physicals laws might be different, but that's just speculation.

    Presumably, the three spatial dimensions and time would be same/similar along the lines of Pengwuino's comments.

    However, perhaps the fundamental particles - quarks, leptons - have different rest masses.

    On the other hand, Chronos may be correct, the universe is fine tuned, and what we have may be what has to be, but not necessarily boring, because it's constantly changing and the universe continues to change - but we cannot see all of it.

    I am reminded of the arguments for the Superconducting Super Collider, that was to be built in Texas. It was to enable the scientists like Sheldon Glashow and Steve Weinberg to reveal the conditions at the beginning of time, i.e. at the Big Bang. I was skeptical then and still am, since we likely cannot recreate the initial conditions.
     
  11. Nov 4, 2005 #10
    So you guys think that if there were other universes out there that it would follow the basic physical laws?
     
  12. Nov 9, 2005 #11

    hellfire

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    My guess is that, if there are other universes or other domains within our universe, the “whole thing” must be a statistical ensemble. If you would restart all again, you would not get exactly the same, but statistically the same.

    This statistical ensemble might be composed of different universes with some different laws but also with some common fundamental laws, or even one could also think that it might be composed of every mathematically possible structure adquiring real existence (stabilizing or disappearing); something like Tegmarks Level IV of multiverses.

    It seams there are lots of possibilities. But, independently of them, I would say that at least some common fundamental law must exist, may be some fundamental theory connecting the physics of all universes, or at least some "rule" in case of Tegmarks Level IV determining that every mathematical structure may pop up to physical existence.
     
  13. Nov 9, 2005 #12

    Garth

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    Quote: "different universes"; show me one and I'll believe you.

    Garth
     
  14. Nov 9, 2005 #13
    David Deutsch would say : "look at the edge and shape of any shadow- light could not behave as it does without the interference of other universes"

    the real world does not operate through Classical Mechanics- but rather Quantum Mechanics- therefore recreating the Big Bang would result in a multiverse where ALL possible physical laws resulted- but a single observer would only see ONE result- and there would be no way to predict which result he would observe
     
    Last edited: Nov 9, 2005
  15. Nov 9, 2005 #14

    hellfire

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    I agree Garth. But I did not claim that they exist. I was only considering the question whether there must exist common underlying physical laws to all multiverses in the hypotetical case that multiverses would exist, even in the case of that extreme Level IV.
     
  16. Nov 9, 2005 #15
    Here's my 2 cents:

    If you had two or more universes that you were theoretically able to observe both, I see no reason why both wouldn't be guided by a set of fundamental behavioral patterns (ie rules). Granted these patterns may be SO different as to inhibit any connections from being observed. But the question seemingly boils down to: "Would the other universe(s) be governed by "rules" [however unrecognizable they might be to us]?" If so, then that is a connection in itself.

    An interesting, but possible divergent rephrasing would be, "if you had multiple universes, both governed by their own (possible unrelated) rule sets, does that suggest a higher order of existence OUTSIDE of a universe system?"
     
  17. Nov 9, 2005 #16
    Another related question, if you had different constants wouldnt that affect the laws as well, I mean different effects on elementary particles.
     
  18. Nov 10, 2005 #17

    Chronos

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    If there are multiple universes, they are unobservable to us by definition. But it's still an interesting concept. Judging by our universe, the only known [or knowable] example of a universe, I think it fair to guess that any 'universe' must possess an enduring and finely tuned equilibrium between the laws it obeys and the constants that quantify that behavior. There is, however, nothing [and I mean literally nothing] that forbids the laws and requisite constants from changing. Hypotheses like variation over time of universal laws [or their corequisite constants] reflect this concept - and they are very difficult to reject without trapping yourself into taking the position the universe is infinitely old and static.
     
  19. Nov 10, 2005 #18
    quantum computers turn this issue on it's head though- quantum computation requires meaningful information processing using the interference between vast numbers of parallel universes-

    not to mention all the situations where theory suggests that interference has profound effects on physical systems- such as the behavior of light- singularity formation- even chemical/electrical interactions- really all forms of physical interactions are modulated by quantum interference according to the basic MWT interpretations
     
    Last edited: Nov 10, 2005
  20. Nov 10, 2005 #19
    it may all depend on the symmetry of the blast, ofcourse if one side outnumbers another, there is a possibillity that anti-matter may out number matter, or in other words nothing can exist but empty space.
    In another blast, there may only be 3 fundamental forces, having no strong force, so the atom will never be formed, therefore no sophiscated mattter will ever form...
    Alot, including the fate of the universe depends on the beginning, if they take one step different from our universe's evolution, the result will be completely different.
     
  21. Nov 11, 2005 #20

    Chronos

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    Partially agreed, setAI. What you are describing is a system where each action dictates the next action. If such a system is not self dampening [i.e., entropic], it will either collapse or explode. An entropic system is the only arrangement where the concept of time has any meaning.
     
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