Re: What did space look like *before* the Big Bang?

Hi Clabaut 

I think the reason you can find no information about what happens before 
the Big bang is that science can not say anything about what happens 
before creation itself. In a similar way science can not say why creation 
occurs. Remember that science is about modelling the real world around us 
using and making predictions based on that model. Why things work the way 
they do is more a philosophical question than a scientific one. That being 
said science has made some speculations about what may have happened 
before the big bang and there has been some speculation about what caused 
the big bang.

The study of the evolution of the Universe and its origins is called 
Cosmology. Cosmology is a mix of High Energy Particle physics and General 
Relativity. it is infered from the velocities of galaxies that the 
Universe is expanding, this implies that it must have been created at a 
`point' in space. Please note that space itself did not exist and the big 
bang created matter that expanded into space. The idea is that space is 
expanded and must have been created at a point. The general feeling is 
that nothing, absolutely nothing, existed before the big bang. This is 
actually a hard concept to grasp. Try to imagine a complete absence of 
anything at all, no space, no matter, no time, nothing and then suddenly 
the entire universe comes into existence for no reason at a point. 

If the entire Universe existed at a point, then expanded, the energies 
involved at the beginning must have been far greater than anything ever 
encountered since. In fact, the energies involved are far beyond the 
capability of modern experiments to recreate. The conditions in the early 
universe are also beyond what is known in theory so theorists can not say 
much about this early epoch. Theory and experiment can begin understand 
what happened after the first few billionths of a second but before that 
is a total unknown. 

Albert Einsteins' General Theory of Relativity provides 5 equations 
(called the Field Equations) that describe how mass, time, density, energy 
and temperature are interelated. These equations have many possible 
solutions. You just need to set the initial values for mass, energy-
density and what have you and see if the resulting model matches what we 
currently see. A commonly accepted solution, the Einstein-DeSitter model, 
allows for 3 possible scenarios based on the initial density of the 
Universe. Either,

1. The Universe keeps expanding forever if there is insufficient matter to 
halt the expansion.

2. The expansion stops and turns into a collapse if there is sufficient 
matter to overcome expansion.

3. A critical case where the matter is just enough to stop expansion but 
not enough to initiate collapse. 

Case 2 implies that the Universe will expand and collapse again. Possibly 
resulting in another Big bang. This means though that the Universe had no 
beginning, just an infinite cycle of expansions and collapse. The other 
two solutions simply have one beginning and exist indefinitely afterwards. 
Case 2 seems like a sensible solution until you look closer. The model for 
case two also says that if this is true the Universe will collapse 
quickly, within a few hundred million years. We know the Universe is at 
least 8 Billion years old, probably 12 Billion years old. If case 1 was 
true there would be insufficient matter to form Galaxies, we know they 
exist so case 3 seems the most likely solution. The Universe had one 
beginning and expansion will continue indefinitely just getting slower and 
slower. Recent experiments seem to imply case 1 though.

What all this says is that the models are by no means accurate yet. They 
still do not explain why the big bang occurred, only what happens after. A 
lot more information is required to fully understand the conditions in the 
big bang. We will probably (though I hope I am wrong) never understand why 
it occurred though.

I would suggest reading The First Three minutes by Steven Weinberg for a 
good non-technical discussion of this. Unfortunately I can think of no 
other, scientific, source that discusses what happened before the Big Bang.

If you wish to discuss this further please mail me.