The Big Bang Cycle

I personally think that most things in nature are cyclical. And because of this, I have a theory which postulates that the universe might actually be much, much older than we think.
How so? Glad you asked.

It is currently an established fact that the universe is expanding. This was arrived at after astronomers noted the "red shift". Exactly what is this "red shift"? Too complex for me but I think it has something to do with how the light spectrum is observed when something moves away from you. Anyway, universe ==> expanding.
And if it is expanding, then it must be expanding FROM somewhere, i.e. there should be some centre of expansion or something. This is where it leads us to the theory of the Big Bang.

As we all know, the Big Bang theory says that all matter in the universe was focused and compacted into a very small space and it exploded and pushed everything outwards. The expansion that we are observing today is the continuation of the initial blast. And generally, the age of the universe is defined as the time transpired after the Big Bang.
But what was going on BEFORE that?

Well, to discuss that, we'll need to digress a little.
Einstein's theory of relativity has this "rule" that if you start at a point in space and travel in a straight line (or what you think is a straight line anyway), then eventually, after a LONG time, you will end up at the place you started. Interesting, isn't it.

SO, if a Big Bang started the whole thing, then given a long enough time, all matter would converge back into the same spot again. There might be collisions and whatnot but as the matter congregate, so would their gravitational field. Maybe black holes will come into play. Whatever. End of the day, if Einstein's theory holds true, then everything will converge, collapse under one immense gravitational field into a highly compact and dense entity.

Then what happens? The entity explodes and starts throwing everything outwards again and thus restarting the cycle. And THAT is why I think the universe might really be a lot older than we think. There might have been several cycles of Big Bangs already.
Now doesn't it just blow your mind when you think about it...?