universe question lol

Smallz3141
Sat, 14 Mar 2009 18:19:29 +0000

You guys bring up some interesting points.



what caused the big bang?



Boy, if I knew the answer to that I’d have the Nobel Prize. We can study the Big Bang with theoretical and observational evidence for a large chunk of it, up to about 10^-43 seconds after the big bang (.00000000000000000000000000000000000000000001 sec). That is the barrier because General Relativity breaks down at the super high temperatures and pressure we know existed at and before that time. Our theories break down, and that is because there is a lack of unity between general relativity (governing the very large) and quantum mechanics (governing the very small).

What we need is a unified theory, a Quantum Gravity, that explains what happens at this time. Then we could further theorize how the big bang started in the first place.



There is a cyclical view of the Universe



That is one theory, that our current universe is one of infinite stages of expansion, then compression of past universes. Maybe the universe before ours crunched back into a singularity (kinda like a black hole), then blew up again creating our universe. The problem with that theory is that it seems to violate the 2nd law of thermodynamics: entropy always increases. If universes kept expanding and contracting, the entropy would be enormous, and while that entropy is high in ours, it’s not as high as would be necessary for this cyclic idea.

However, Black Holes can consume entropy, so one thought is that the black holes eat all of it. That means that either they would have to re-spew the entropy as the black holes “big banged” again, or there would need to be a ton of black holes in our universe, which we don’t see. Also with Dark Energy and the overall lack of matter (regular and Dark), it doesn’t seem likely that our universe will ever contract. Not to say this cyclic universe theory is disproven, but it doesn’t look good right now.



the Universe does indeed have a “boundary.”



No, that isn’t the case. The problem is people are thinking of the universe kinda like a table top: ‘‘Even if it expanding, there is an end to the table where you could ‘fall off’.’’ The universe isn’t a table (shocking!). It’s better to think of it like a sphere (like Earth), and this sphere is expanding at an accelerating rate. But you can never fall off the sphere (just like you can’t fall off of earth), there is no boundary.

I hope that helped.