In the Ender's Game series, it's theorized that existence always has been and always will be. Time is explained as the radius of a sphere. The center of the sphere is the beginning of time, of things, of mass, of existence. We're at a certain radius on the sphere, and, as the universe expands, the radius increases. It's a really interesting explanation (though, greatly rooted in fiction I'm sure) if anyone is interesting in reading. (The books kick ass too.)

What is it they say about silence being golden?