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What was before the big bang ?

  1. Jan 14, 2005 #1
    I had a discussion with some friends about this. I figured this would be a great place to get a real anwser ( since we are all want to be's )

    What was before the big bang ? There had to be something in order for the matter that was there to be condensed in the first place right ?

    Did time exsist before the big bang ? I say it did but a friend is saying it only started when the big bang occured.

    happy friday :cool:
     
  2. jcsd
  3. Jan 14, 2005 #2

    Integral

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    The big bang is the beginning of space time as we know it. We can not even make a conjecture about any thing pre big bang. The general consensus is that there was nothing, neither time nor space before the big bang. The big bang did not happen in space it happed TO space.
     
  4. Jan 14, 2005 #3
    There are actually quite a few possible alternatives, even though most of them are somewhat speculative. string theory predicts branes colliding which causes the bang, there is also a theory (or so I've read in scientific american) closely related to strings that a pre-bang universe like ours existed, suddenly collapsed into a singularity then bursts out again (not too sure about the details though).

    May be wrong...
     
  5. Jan 14, 2005 #4
    actualy the consensus is an infinite/eternal Multiverse out of which big bangs emerge- not a unique Big Bang from nothing-

    the idea of a big Bang from nothing was a briefly popular error among cosmologists commonly refered to as the fallacy of creation ex nihilo which Spinoza/Hegel demonstrated to be absurd/irrational centuries ago- it was a case of too many physicists not posessing a firm enough foundation in Philosophy or Logic- or none of them would ever have so embarassingly suggested the concept in the first place-

    creation ex nihilo is AXIOMATICALLY absurd
     
  6. Jan 14, 2005 #5

    selfAdjoint

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    Phooey! An axiom comes out of our minds and has no binding power on what the univrse does. I can't imagine scientists being bound by the lucubrations of Spinoza and/or Hegel (much as I respect both men) any more than they are bound by the stories in Genesis.
     
  7. Jan 14, 2005 #6

    marcus

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    You probably read about the work of Martin Bojowald
    (universe has a prior contraction phase)

    Here is a recent piece in Nature Journal about Bojowald
    http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v433/n7021/full/433012a_fs.html
     
  8. Jan 14, 2005 #7

    Chronos

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    The ultimate question and one which may never be satisfactorily answered. The uncertainty principle [and some would claim Godel's theorem] already constrains our ability to make predictions at the most fundamental levels of reality. Yet, oddly enough, the uncertainty principle may hold the key.

    Creation ex nihilo is no more absurd than an infinite cycle of universes begetting universes, or other ad infinitum pre-existing constructs. If a poll has been taken among theorists, I have not seen it. So far as I know, the consensus on what preceeded the big bang ranges from unknown to unknowable. All such theories are regarded as speculative. Authors and relevant papers are too sparse to suggest any such theory enjoys broad support.

    Theoretically, a universe from nothing has a sound theoretical basis: something multiverse and other scenarios are hard pressed to claim. Quantum theory, which has been experimentally validated, provides a mechanism for creation ex nihilo. I just happen to have a few links:

    Birth of the Universe
    http://zebu.uoregon.edu/~js/ast123/lectures/lec17.html

    Simple quantum cosmology: Vacuum energy and initial state
    http://arxiv.org/abs/gr-qc/0501014

    Future and Origin of our Universe: Modern View
    http://arxiv.org/abs/astro-ph/9912054

    Can the Universe Create Itself?
    http://arxiv.org/abs/astro-ph/9712344
     
  9. Jan 14, 2005 #8
    On the contrary, the concept of a multiverse is absurb because the word "universe" means "everything." So really the universe would be the "multiverse." So now back the question. Where did it come from and what was it like before it? Oh, wait. The "multiverse" theory comes right back to the same problem it was suppost to solve!
     
  10. Jan 15, 2005 #9
    :uhh: Foreplay?
     
  11. Jan 17, 2005 #10

    Phobos

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    We can at least say that Big Bang theory applies to the visible universe.
     
  12. Jan 18, 2005 #11
    point one: none of the many ideas/conjectures suggesting that the Universe emerged from nothing actually posit that it came from TRUE Nothing- Nothing is Nothing and if any kind of chaotic quantum fluctuation [hmmm- QM is already background dependant anyway!] or ANY kind of event comes from this "nothing"- it is NOT nothing but Something by definition- true Nothing has no extent/duration/dimension/form/or causality Nothing has no qualities WHATSOEVER- not even the quality of EXISTENCE- therefore no events and no being/existence of any kind can emerge for it- there is no IT to emerge from! anything less than this absolute is NOT nothing at all-

    point 2: even if our universe came from a true Nothingness- if a universe requires nothing to come into existence then there is NO rational way to suggest that universes aren't continuously/eternally being born!- many state that one cannot assume other universes when we can only see ours- but I think it is easy to show the opposite is unavoidable: if a universe can come from nothing- then it literally needs nothing to Be- therefore there is no way to avoid an infinitude of universes unless you posit a god-like mechanism that prevents others from being born and only allows this one unique world to exist- so to me the suggestion that there is only one universe is not at all the simplest explanation and is quite untenable- the idea that we can only assume our universe requires a mystical/magical mechanism to prevent other worlds from popping out of literally nowhere! that is far more speculative and fanciful than any primitive mythology by far!

    ultimately given that Nothing cannot really be Nothing- and that other universes are unavoidable when they require nothing to be born- reason necessitates that the idea of Creation ex Nihilo is actually the SAME idea as that of an eternal multiverse! the disagreement comes from using different definitions for "nothing" the error of Creation ex Nihilo is not that it is wrong- but that it is right and doesn't address the consequences of being right so it just misleads- it is a conclusion jumped at too soon-


    you know as well as I that the definition of universe as everything is long past- universes-plural is now such a ubiquitous concept that even school children and soccer moms have heard of "parallel universes"- and a quick search of the word "universes" on the arXiv yielded more results than the search engine could display [300+]

    an ETERNAL multiverse [or if you prefer a timeless nothing-like void out of which chaotic quantum fluctuations give rise to universes] has no origin problem- something which always has existed has no need for a creator or a birth mechanism- "it simply IS" as Hawking stated- and is always the simplest solution to the fundamental existence of the Cosmos- it's the real Answer beyond "42"

    back to the main point: I think all of this is ultimatley why virtually every major cosmologists/theorist has published a paper or article with their own multiverse-model-du jour- it's not really hard science but the fundamental ideas of a multiverse simpy cannot be ignored out of existential/ontological necessity
     
    Last edited: Jan 18, 2005
  13. Jan 18, 2005 #12

    Chronos

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    It's a thorny problem, for sure. That's why this stuff is called speculative. What we know from what we can see indicates what we now refer to as the universe [time, space, matter and the four fundamental forces of nature] emerged from a formless state where they did not have separate identities or definable properties, at least not in terms to which we can relate. Is this nothing? Good question. 'Nothing' is surprisingly hard to define. One of the links I posted puts it this way:
    The philosophical concept of 'nothing' is an absolute, a state that is not even a state. It cannot be ascribed any properties whatsoever without becoming a philosophical 'something'. Such a state is obviously nonphysical, which renders it useless for scientific purposes. All kinds of otherwise well established theories, like GR, produce nonphysical solutions when you consider all possibilities. Those solutions do not invalidate the theory, they are merely ignored. I have one more excerpt:
    So indeed, the universe did not arise from a philosophical 'nothing', rather it emerged from a background state that is implicitly undefinable. That is about as good a description of 'nothing' I can think of that is not unphysical.
     
  14. Jan 20, 2005 #13

    Nereid

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    Another thing to keep in mind: homo sap. has done scientific work on this question for only a trivial fraction of the age of the universe (and 'scientific' itself is, perhaps, an even more recent 'invention'); is it not a measure of our hubris that we think we have even the most tenuous handle on answers to sero's question?
     
  15. Jan 20, 2005 #14

    marcus

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    Last edited: Jan 21, 2005
  16. Jan 20, 2005 #15
    uncertainty principle, bah.
     
  17. Jan 21, 2005 #16
    So Chronos, what was before the Big Bang was some kind of field or state that is unexplainable....how about the universe emerging from a quantum vacuum like that one link states?
     
  18. Jan 21, 2005 #17

    Nereid

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    Yeah, why not?

    Then again, maybe 'before the BB' was a state of knaseroth-ness, in which everything was infused by oihntrokno, and then along came qweradvnk, and BB!

    If you're taking a scientific approach to this, you have to ask 'how could you tell?' :smile:
     
  19. Jan 22, 2005 #18

    Chronos

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    Among the big questions in cosmology is, could the precursor state of the BB leave a trace signature in the background? So far, the data has only affirmed the post emergent state has left a trace.. and it is remarkably consistent with the predictions of a hot big bang model [modern theory]. No one is really shocked by that discovery.. they are only puzzled by the new questions the data alludes to. That's why science is fun. Every time we peer deeper into the universe, it opens up a new puzzle box.
     
    Last edited: Jan 22, 2005
  20. Jan 22, 2005 #19
    There had to be some kind of field or state before the big bang, that "something out of nothing" is really confusing to me it doesnt make sense, quantum field maybe radiation field from a pre-existing space....i cant really explain it
     
  21. Jan 22, 2005 #20
    Suppose we think of the steady state universe. Then time is in the set [tex](-\infty,+\infty) [/tex]. In the big bang universe time is in [tex](0,+\infty) [/tex]. In the first case we don't ask what happened before [tex]t=-\infty[/tex], but in the second case we do ask what happened before [tex]t=0[/tex]. Why should this be? One can transform between [tex](0,+\infty) [/tex] and [tex](-\infty,+\infty) [/tex] with a simple change of variable, so as I see it they are essentially equivalent. It seems perfectly reasonable to me to say that [tex]t<=0[/tex] doesn't exist, as it would be saying that [tex]t<=-\infty[/tex] doesn't exist .
     
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