One theory of the universe's birth is called the Big Bang Theory. In this Theory, the universe started as a spinning mass a little bigger than a point. Its mass was very dense as the radius was small. As a result, the gravitational pull was great. The dense, spinning universe suddenly implodes and as a result of the implosion, the universe exploded.
All contents spread themselves and since the original position spun, everything else spun also.
The following topics help prove the Big Bang, in that it proves an expanding universe. Olber's Paradox states that there are infinitely many stars. Agreeing to this we conclude that the universe is infinite in size. If the universe were infinite with stars uniformly distributed throughout, then any line of sight should fall on a star, therefore the night sky would be bright everywhere. This can imply that the universe is finite.