QUOTE : You know about the Big Bang, right? They believe that the universe was born in a tremendous explosion twenty billion years ago. I can mathematically express the form of the universe, from its birth to the present. It's all about differential equations. Most phenomena in the universe can be expressed with differential equations, you know. Using them, you can figure out what the universe looked like a hundred million years ago, ten billion years ago, even a second or a tenth of a second after that initial explosion. But. No matter how far we go back, no matter how we try to express it, we just can't know what it looked like at zero, at the very moment of the explosion. And there's another thing. How is our universe going to end? Is the universe expanding or contracting? See, we don't know the beginning and we don't know the end; all we can know about is the in-between stuff. And that, my friend, is what life is like.