Quote:
Originally Posted by Linus
Since we've been discussing certain things in the Religion thread and I can't remember it being asked here...
Before the "Big Bang" what was there? Do we know if something else existed or was it truly ... well... nothingness?
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This is actually what is called an 'ill-formed problem'. By that I mean that it is a question that we most likely do not fully comprehend.
To understand why, it's necessary to go back to the moment go over why the Big Bang theory came into existence and what it says about the early universe.
The Big Bang is one of those necessary theories. The Universe is expanding, this much is very clear because objects far from us are moving *away* from us. Since gravity is *always* attractive this requires an explanation. The prior model--the Steady State model--cannot explain an expanding Universe. Since we know, because we do it everyday, that gravity can be overcome by a sufficient force there must have been SOME force that began the expansion of the Universe. This initial event would have to be strong enough to overcome the long-term tendency of matter to attract. Now, here is where we get into the necessary part. If the Universe is expanding (and it is) then it is possible to say that the current state of the Universe (N) is derived from some earlier state of the Universe N-1. N-1 is derived from an even earlier (less expanded) state N-2 and so on. Eventually you get to a state of the Universe that is VERY compact--this is the Universe just at the moment of the Big Bang.
One of the great quests in contemporary physics is a theory that allows us to model the state of the Universe at the moment of the Big Bang. What we need is a theory that can account for an exceedingly small (smaller than the nucleus of an atom) object that is VERY massive. Right now we have two separate and disagreeing theories to deal with objects--special relativity deals with very massive objects (thus explaining gravity, black holes, etc.) and quantum mechanics to deal with very small objects (thus explaining what is happening inside an atom). The problem is that these two theories lead non-sensical (infinities) answers when you try to use them at the same time. This is not to say either theory is wrong--both SR and QM are confirmed to a truly amazing degree of accuracy. QM has been tested to such a degree and confirmed to a level of accuracy such that it would be like measuring the distance between a sign saying "Welcome to Los Angeles" and another sign saying "Welcome to New York City" and being accurate to within the width of a single human hair. SR has been confirmed time and time again in the last 100 years (well, 96 years to be accurate). So both theories are as robust as any you'll find in science.
There's some part of the picture we are missing and so, right now, I don't think we can ask a *meaningful* question about 'what happened before the Big Bang' because I don't think we understand what that question actually means.
Btw. when I said that it’s a necessary theory I meant it in this sense. I KNOW that you had a mother and a father and you were born a baby. I know this because you are alive and therefore, by definition, you got half your genes from one parent and half your genes from another parent and since no human woman could survive giving birth to a full-grown adult you must have been born a baby. We can derive, from your current state, that at some point you were smaller than you are now. The same applies to the Universe, given the current expanded state of the Universe and given the ongoing expansion, there MUST--by necessity--be a point when the Universe was in a much smaller state than it is now.
Cheers
Aj