Big Bang Theory

[Eradon]

I don't really know where to post this, but everyone asks me how (1) the small particle that became the universe was created, and (2) what set off the big bang. I know there's been a lot of debating over this, but what is the generally accepted explanation, from the naturalist point of view? I've always assumed that since there were no laws of physics before the big bang, matter could be created out of nothing, and things could happen with no cause. But I have a feeling I'm completely wrong...

Eradon

[Dr.GH]

The most clear explanations I have found that are linkable are:

http://nedwww.ipac.caltech.edu/level5/Watson/Watson_contents.html

http://www.astro.ucla.edu/~wright/cosmolog.htm

There are many other sites as well. But, based on my reading, (and probable limited understanding) the key points are that it was not a "particle" that exploded into the universe, rather the dimensionality of the universe expanded and this generated mass and energy. How? I have no idea.

[Barron]

09-06-2003 @ 11:31 PM post located here (http://www.theologyweb.com/forum/showthread.php?s=&postid=205072#post205072)
Eradon:

I don't really know where to post this, but everyone asks me how (1) the small particle that became the universe was created, and (2) what set off the big bang.

I'm not sure where you got that thumbnail, but it's oddly phrased. GH provided some good links, and I'll give you a short version here.

What we know: The universe is expanding and cooling. Looking at the data (including the headache inducing general relativity) we come to the reasonable conclusion that the early universe was small, hot and dense. To phsyics types, this brings to mind an explosion, hence the term "Big Bang". As we "run the film backwards" we go through from very interesting epochs. We see the diverse forces of nature unify into fewer forces, we see matter overwhelmed by evergy, lots of fun stuff. Astrophysicists have very good models of the early universe and much of their theories can be tested by observation of the universe today.

But all this sort of avoids the really interesting question, "what was THE beginning like?" There are theories about this too, but they are much more speculative. Interesting, but speculative. All of them are, of course, naturalistic (being science and all), but none are definative. There is no simple answer to the "what came before" question.

I know there's been a lot of debating over this, but what is the generally accepted explanation, from the naturalist point of view? I've always assumed that since there were no laws of physics before the big bang, matter could be created out of nothing, and things could happen with no cause. But I have a
feeling I'm completely wrong...

Sort of wrong, and certainly not right. The problem is it's not a simple question that gives simple answers. All of our everyday, human common sense just falls apart in the early universe. Distance scales require quantum mechanics, temperature scales require quantum field theory and space/time curvature requires relativity. All of these are completely removed from our everyday experience (where our common sense was developed). I'd be happy to point out the holes in the theistic arguments of Kalaam, first cause and cosmological, but that's a different issue.

Other suggestions for reading are Stephen Weinberg's "The First Three Minutes", Brian Greene's "The Elegant Universe" and, of course, Hawking's "A Brief History of Time".

Barron

[Harlequin Solit]

From what I've heard, all these scientists think teh universe was created by one big explosion because all the stars and galaxies we know of seem to be coming from one direction. Until we can see all of the galaxies, how do we know that this isn't just something that happened in our part of the universe?

[sylas]

10-10-2003 @ 01:57 PM post located here (http://www.theologyweb.com/forum/showthread.php?s=&postid=239788#post239788)
Harlequin Solit:

From what I've heard, all these scientists think teh universe was created by one big explosion because all the stars and galaxies we know of seem to be coming from one direction. Until we can see all of the galaxies, how do we know that this isn't just something that happened in our part of the universe?

They are not really "coming from one direction".

What we observe is that all the galaxies we see are moving away from us, and the further away they are, the faster they are moving.

(Quibble. There are random localized motions imposed on the general trend. Andromeda, for example, is practically next door to us in galactic terms (2.6 million light years) and is moving towards us.)

The effect is not like the aftermath of an explosion, but more like raisins in a loaf of rising bread. The motion is such that there is no center. We see all galaxies moving away from us in such a way that any other galaxy would similarly all the rest moving away from it. There is no distinguished center.

We don't in fact know whether this expansion is localized effect. Some models for the universe do allow for various kinds of discontinuity or bounds, but these are, of course, speculative. We don't know how the expansion got started, and the eariest stages remain very mysterious, in conditions where modern physics simply breaks down.

Science works by developing general models which give a good explanatory framework for relating many phenomena and allow inference of other consequences, which in turn is a stringent test of the model.

For example, the inverse square law of gravitation is a general model which explains many diverse motions.

An even better model is given by general relativity.

One of the features of general relativity is that it explains (and even predicts) the kind of expansion we observe with receding galaxies. It is an expansion of space itself; not simply a motion of things away each other.

The simplest solutions to the relativisitic field equations of a nice smoothly expanding space, and that is pretty much what we observe to the limits of what may be seen. The whole picture could indeed be more complex; but we can't say much about that at all in the absense of any observable information, and in the absense of a comprehensive model for the initiation of the expanding spacetime we do see.

Cheers -- Silas

[Harlequin Solit]

Hmm.... Well I saw a documentary in RE that said that it was like an explosion... But this was a flawed documentary that was about 30yrs old. :ahem: Kids: DOn't believe anything you see in school! :whistle: :thumbd:

lol, you have some good points there, silas. Thanks.

[beeblebrox]

There was an article in SciAm a while back talking about the whole multiverse thing.

Now each time I boil water or make soup, I imagine that each bubble rising to the surface is its own universe billions of years wide and expanding but unaware of all the other bubble universes around it or that it is actually moving up instead of only out. Then POP! and we are soup again!

Now you'll have to think of it too!

beeble

[Harlequin Solit]

Mmmm.... Soup.

lol, :joy: nice one... Interesting theory.

[BohemianXQueen]

Creationism and Evolutionism are the same theory looked at in a different way. One from the literal perspective, one from the spiritual.