As I understand, there is an idea out there that omega may equal 1.0 and so the Universe has balanced energy. That is, its rate of expansion is balanced by its gravity. Just so I understand the implications – does it follow from this that the expansion and contraction energies exactly cancel and the Universe came from nothing?
There is an idea out there that says that right? — or am I way off base in my understanding here?
I’m very far from being an expert, but I remember reading on this message board how before the universe was “created”, there was nothing. If there is absolutely nothing, then there are no laws. If there are no laws, then there’s no reason something can come from nothing.
That’s just one way of thinking, it’s not a proven fact or anything. I’m sure some other people will come and confuse us further.
Hmm, I just reread the OP and realized I didn’t really answer your question. Nevermind, I thought you were asking something else and only skimmed over your post.
…its rate of expansion is balanced by its gravity…
Unfortunately, this is not the case, though it was thought that the universe was going to expand and then contract for most of the 20th century. After a huge research project lasting many years, astronomers have concluded that not only is the universe expanding, but it’s expansion is actually accelerrating. Unfortunately, no-one definitively knows the processes that cause this (lots of speculations involving quantum here).
Is this because the net gravitational effect grows less as everything moves away from everything else?
It’s got to suck to have a post per year and make a typo
This is what I get for reading old (circa 1990) Stephen Hawking books. Hawking said that the Universe may be “the ultimate free lunch.” I thought - “well hell, this is what he’s talking about.”
No, I believe that the acceleration comes from a fifth fundamental force (after gravity, electromagnetism, and the strong and weak forces).
You could spend hours at this Frequently Asked Questions in Cosmology site getting answers to many of the questions that are asked on this general subject.
I believe what is being pushed right now is the theory that ‘nothing’ is against the laws of physics. Therefore, there was always something, and you have to delve into some pretty intense discussion about quantum physics.
Much of what I’ve been reading about the origins of the universe suggest that ‘nothing’ was not the beginning…that ‘nothing’ is not possible…and that the moment you have nothing something will appear out of nothing, so that there never was a moment you had nothing.
So, while I might be confused, the jist of what I’m saying is that you might have to stop thinking about ‘nothing’ as ever being just, well…nothing. There was always ‘something’. We just don’t know what that point looked like right before things got going, but at some point as close to nothing as possible.
Getting off the OP, but this “nothing” concept has been discussed several times before in this MB. A vacuum is not nothing. It is nothing in a proscribed space. Virtual particles can exist in a vacuum and this is one theory on how the Universe began. A pair of virtual particles became real particles.