MY THEORY.
I was watching "Steven Hawking: The Theory of Everything" and it explained how the Big Bang is in relation to black holes. He states something along the lines of how prior to the big bang, the Universe was smaller than the size of an atom.
From the documentary, he explains his theory of how once a star dies, it continues to shrink into a black hole where gravity reaches (ignorantly) infinite where not even light itself could escape. He then states that througout space, there is Negative and Positive mass particles which (within nanoseconds) splits, collides, disapears, and repeats. When one comes in contact with a black hole, and the the negative particle gets trapped into the black hole and the positive particle has enough energy to escape, the positive particle will continue to roam through space as the negative particle greatly affects the black hole.
Since it's a negative mass particle, it will cause the black hole to shrink and due to the positive mass particle drifting away, the black hole will then release radiation towards the positive. As the black hole releases radiation and shrinks, it will continue to heat up to the point where it is microscoptic and at very high temperation. At this point, the black hole with EXPLODE and all the debris will be released out into space.
Now if you think of this in a cycle, it may be the the answer to the the mysteries held prior to the Big Bang theory.
So my theory:
What if the universe has really lived on infinatley. Considering how scientists are predicting that universe is expanding and the big bang is was the beggining of time. In many many years, all these planets are bound to come back in contact with eachothother. What if our big bang, was just part of a cycle. How what if our universe had already existed many times before. And how life had grown to fully advance itself and at the dawn of time everyone had gone extinct due to the recycling of the universe. Where the universe expands; life grows, then constacts; where life dies. And everything starts over again from scratch.
Maybe there has been multiple "cycles" the universe had experienced. And how it could happen again over and over again in the future.