contracting, expanding, beginning, end.... these are all words that refer to things we can comprehend. Words that we use to try to make sense and try to understand....
When talking about the universe, there is something that scientists autmaticly do. They talk with basic human words but they use them to make theories which humans can't comprehend. There is not a single person who can understand and explain how big the universe is. We can only "imagine". That's because the human brain can't handle such complex stuff...
A nice example: Everybody knows what 3D is and can comprehend it. But there is also 4D, now imagine how that will "look". ("look", example of such a word which I talked about in the first paragraph. Actually "to look" means you can see something, and seeing means 3D, not 4D...)
And when we come to the universe-talk, everything is like that, we "say" it extracts/compresses. We can't comprehend that, because the universe is infinite, yet it contracts... So that should be impossible, yet it is possible (proven)...
The Big Bang (or something similar) has existed. Scientists say that everything comes from a single "something" (calling it "atom" would be wrong). This has been proven, yet we can't comprehend that or put it in words and describe it. We can only give a relative explaination and simplify it by doing that.
But by doing that, we also make mistakes on purpose. It is wrong to build further upon those "simple" explainations (with the included mistakes), and that is exactly what you're doing if you say things like "the big bang existed, so everything came from a single thing, so that means matter is finite"...
Also, another thing. Many people say that space itself contains nothing. Well that has been proven to be wrong. "Nothing" does contain something; there is something called "black matter", which is the opposite of matter. Again something we can't comprehend, but it does exist. So even if all the matter was contracted again (big bang-loop-theory), space would still exist and would be "filled" with black matter (or sometimes called anti-matter)...
Also don't forget that the laws of nature as we know them, don't exist in space as we know them. In space there are other laws. Laws which have to be yet discovered, or to put it in a better way: the big law has yet to be discovered. Because many laws have been discovered already. But many laws contradict other laws.
It's nice to talk about all this stuff, but you must not forget that it is just talking about very simplified things and thus you can't make assumptions and theories. We aren't scientists. We can only try to understand what those formulas means. Heck even scientists have often problems understanding their own laws.....
If you are interested in those things, I suggest to read a book from Stephen Hawkins (their is that dude again
). His string-theory (everything exists of "strings") is very very very complex and explains many strange things happening in the universe (black holes, worm-holes, relativity, mini-big-bangs, contracting, expanding, lack of time, butterfly-effect, etc.. etc..), but at the same time it can realy explain the basic laws of nature (from Einstein, Newton, etc...) on earth as well. And although it is very complex, it can put things realy simple by comparing it to strings of a violin...
I'm going to end this strange post
I can talk about it for hours, but my English isn't good enough to do that. All I can say is that it is fasinating and fun to talk about it. But let the scientists do their job, and let us do ours: enjoying life and wondering how beautiful it can be (and how shitty it can be).....
/ 
