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Thread: Is the Big Bang necessarily the absolute 'beginning' of everything?

  1. #1 Is the Big Bang necessarily the absolute 'beginning' of everything? 
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    Lately I've been having some discussions with people online (theists), and one of the things that I find is almost invariably brought up on at least one occasion is that the Big Bang is supposedly, according to science, the absolute beginning of everything, and that this has been proven by something known as the Borde-Vilenkin-Guth Theorem. Now, I know that the latter comment is simply not true, as all three of those scientists have gone on record and clarified that their theorem only demonstrates that the expansion of our universe has a definite beginning, not necessarily existence itself.



    But as for the Big Bang itself, I was always under the impression that all science has been able to say about it thus far is that it is the beginning of the universe in its current state, not necessarily the beginning of our universe in the absolute sense of the term (discounting the possibility, for the sake of argument, that our universe is only one of an infinite number of parallel universes, which if I'm not mistaken recently had some evidence found for it). That is to say, contrary to what the Kent Hovinds of the world would have the public believe, I have never heard any cosmologist or theoretical physicist make the claim that the universe actually did emerge out of a state of complete nothingness (in the most absolute possible sense of the term), and I personally think that such a thing is most likely a logical impossibility.



    Is my understanding of the science more or less accurate? Or have I been misinformed?


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    Brassica oleracea Strange's Avatar
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    Quote Originally Posted by Fanghur View Post
    Lately I've been having some discussions with people online (theists), and one of the things that I find is almost invariably brought up on at least one occasion is that the Big Bang is supposedly, according to science, the absolute beginning of everything, and that this has been proven by something known as the Borde-Vilenkin-Guth Theorem. Now, I know that the latter comment is simply not true, as all three of those scientists have gone on record and clarified that their theorem only demonstrates that the expansion of our universe has a definite beginning, not necessarily existence itself.
    I am not familiar with this theorem (and probably wouldn't understand it anyway) but for people who want more info, there is a debunking of the claim here: http://debunkingwlc.wordpress.com/20...guth-vilenkin/

    Also, I assume their theorem is true for GR as it is currently formulated. I don't know if it would apply to Einstein-Cartan theory or a theory including quantum gravity.

    Vilenkin is also one of the people behind "eternal inflation", which is one of the models that proposes multiple "big bangs" and multiple universes.

    But as for the Big Bang itself, I was always under the impression that all science has been able to say about it thus far is that it is the beginning of the universe in its current state, not necessarily the beginning of our universe in the absolute sense of the term
    I'm not quite sure what distinction you are drawing there. But the big bang model says nothing about "creation" just that the universe has expanded from a hot dense state.

    I have never heard any cosmologist or theoretical physicist make the claim that the universe actually did emerge out of a state of complete nothingness (in the most absolute possible sense of the term), and I personally think that such a thing is most likely a logical impossibility.
    Isn't this pretty much what Hawking says? (Although it is still just speculation with as much validity as "God did it".)


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    Brassica oleracea Strange's Avatar
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    Quote Originally Posted by Strange View Post
    Also, I assume their theorem is true for GR as it is currently formulated. I don't know if it would apply to Einstein-Cartan theory or a theory including quantum gravity.
    I just noticed that Sean Carroll made exactly the same point in the article I linked. How cool is that!
    ei incumbit probatio qui dicit, non qui negat
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    Forum Bachelors Degree Kerling's Avatar
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    In short, it is like this:
    Only things that are observed are part of our universe. The rest simply doesn't affect us. (not even on a physical level)
    We can only observe what is inside the universe. So if you prove that the universe has a beginning, you prove that only things that are part of our universe is stuff that came after the beginning of the universe.
    Whether there was something in front of that. We don't know. If there is, we'll observe it one day. There is a good reason to look, deep, deep into space.
    If there isn't, well no biggy.

    Either way so far we cannot disprove either theories. So it's an ongoing debate. There are some effects though, which might chance physics that people are looking for. But it is very much an active field of study.
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    The onus of proof is on the instigator of any therium... Is there a God, and prove that. Run head first into this.

    Was the BigBang the begginning of the Universe. As we can not see of what was before the great expansion and cooling.

    I am not at present inclined to say Yes, No and its Turtles all the way down... We do not know.

    Not only do we not know, but we may never. The expansion rate seems to disqualify our quest somewhat.

    but there does seem to be a glimmer of hope. That as we understand the workings of subatomic particles,

    and that area of knowledge is expanding.

    We may gain a insite as to the BigBang and the possible triggers that activated the quantum irregularity that is this Universe.

    If energies existed, what triggered the change to mass.. We can NOT say a God did this as we have NO proof of such a God..

    We do have the scientific principal. That it demands proofs as yet unavailable.. ( evidence..)
    Last edited by astromark; May 31st, 2013 at 11:28 PM. Reason: added for Alex G
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    Anti-Crank AlexG's Avatar
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    We do have the scientific principal. That it demands proofs as yet unavailable..
    The scientific method doesn't demand proof, just evidence.
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    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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    Forum Bachelors Degree Kerling's Avatar
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    neither of the two!theories are not supposed to be proven. only disproved. the failing in managing to disprove something makes it acceptable as. theory. a good theory is easily disproved, and is good because it can't be disproved, even though it should be simple. a bad theory is hard to disprove.but a good theorists tries to disprove his own theory dillegently.that is how science works
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    I believe that it's well known that nobody knows for sure what happened prior to the big bang. In fact Peebles states quite clearly in his cosmology text that there is no event within the big bang theory at which there was an actual event called the big bang. Some theorist believe that there was something prior to the big bang inflationary period. Look up PreBig Bang cosmology on the internet.
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    Anti-Crank AlexG's Avatar
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    Also look up Eternal Inflation.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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    A friend of mine is an expert in these areas and I asked him the question this thread is about. I can't say who it was so as to protect his identity as well as my own. His response is very similar to mine though
    If you take the "big bang" to be a real singularity in the Einstein equations (e.g., the invariants of the curvature tensor grow unboundedly as the singularity is approached), then it makes no sense to speak of "before the singularity." It would be like asking: "What happens before anything happens?"

    But if you don't believe it is really a singularity (as e.g., in the Ashtekar loop quantum gravity approach), but just a place in the neighborhood of which the classical Einstein equations break down; then it can make sense to discuss what might possibly have happened before that breakdown. The answer will depend on the theory you adopt to replace the Einstein equations. For example, Trautman has shown that if you assume a classical theory with a non-vanishing torsion tensor you can avoid a singularity.


    My main point: The question and the possible answers are theory-dependent. We have no direct access to "reality," i.e., some way of approaching these issues that is theory independent.
    I mentioned Peebles above. To be exact here is what he says on the subject. From Principles of Physical Cosmology by P.J.E. Peebles, page 6. Following his description of the standard model he writes
    The familiar name for this picture, the “big bang” cosmological model, is unfortunate because because it suggests we are identifying an event that triggered the expansion of the universe, and it may also suggest that the event was an explosion localized in space. Both are wrong. The universe we observe is inferred to be close to homogeneous, with no evidence for a preferred center that might have been the sight of the explosion. The standard cosmological picture deals with the universe as it is now and as we can trace its evolution back in time through an interlocking network of observation and theory. We have evidence from the theory of the origin of the light elements that the standard model successfully describes the evolution back to a time when the mean distance between conserved particles was some ten orders of magnitude smaller than it is now. If it is found that still earlier epochs left evidence that can be analyzed and used to test our ideas, then that may be incorporated in the standard model or some extension of it. If there were an instant, at a “big bang,” when our universe started expanding, it is not in the cosmology as now accepted, because no one has thought of a way to adduce objective physical evidence that such an event really happened.
    That last sentence is the most imortant part of that paragraph as it pertains to the topic of this thread.
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