Tuesday, April 27, 2010

Large Thoughts

I’ve been having large thoughts lately. I’ve been thinking about the universe. Those who study such things say that when we talk about the universe, we must distinguish between the universe and the "observable" universe. We know how big the observable universe is. We don’t know how big the entire universe is. It may be many orders of magnitude larger than the observable universe. In fact, it may be infinite.

Before the universe was … I almost said “created”, but that would be jumping to a conclusion … before the universe came into existence, there was a void: no space, no time, no matter, no energy. Nothing. Nada. Zip. Many people are under the mistaken impression that before the Big Bang occurred, there was just empty space, and the Big Bang was an explosion that occurred somewhere in this empty space. But that is not the case. Before the Big Bang, space did not exist. Time did not exist. Hence my use of the term “void”. The Big Bang created “spacetime” and all the matter and energy within it.

All very good. But at the instant of the Big Bang, something else came into existence … something we don’t usually think of as coming into existence … something we tend to think of as always having been here. And that something was: the laws of physics. Plank’s constant. The speed of light. Quantum physics. And all the rest: mathematics, geometry, trigonometry, integral calculus, differential calculus. Etc., etc., etc. Isaac Newton didn’t invent calculus. He discovered it.

Where did the laws of physics come from? Why should there even be any laws of physics? If the void had existed for eternity without spawning a universe, then why should our universe have suddenly popped into existence 13.7 billion years ago? Why did the Big Bang (“creation”, if you prefer) happen at that particular moment? Why not a trillion years earlier … or later? Why not never? Does a question of time in a timeless epoch even have meaning?

And now, theorists theorize that there may be many universes … perhaps an infinite number of them. This collection of universes is called the multiverse. The laws of physics may be different in each universe. In many universes, the laws of physics are such that matter could not form … or stars could not form … or life could not develop. In our universe, the laws of physics, by sheer coincidence, turned out perfectly for us.  According to this theory, we live in a rare “Goldilocks” universe where all the laws of physics just happen to be fine tuned for us to be here. That’s not a very satisfying explanation. You might as well say it was magic.