Thinking About the Universe

Sometimes I think about the Universe. It’s hard for me to conceive of the Universe having a beginning, but it did. There was a time when our Universe and its billions of galaxies did not exist. Then suddenly, seemingly from nowhere, it sprang into existence. That happened 13.82 billion years ago. We call that event the Big Bang. The Big Bang is the best theory we have come up with to explain what we see when we peer into space.

We think of space as “empty space”. Of course, space contains galaxies and dust and radiation, but if you take all of that away, what’s left? Empty space. Except, space is something. Meaning, space is not nothing. It is definitely something.

When we point our telescopes at other galaxies, we can see they are moving away from us. The farther a galaxy is from us, the faster it is traveling away from us. This doesn’t mean there is something special about our place in the Universe. The fact is, this truth holds for every galaxy. If you could travel to any place in the Universe, you would see all the other parts of the Universe moving away from you.

You might think all these galaxies have some outward velocity, that they’re traveling though space like pieces of shrapnel traveling outward from a bomb. But you would be wrong.

What is happening is this: the space between galaxies is expanding. Space itself is expanding. Galaxies are embedded in space, and as space expands it carries the galaxies away from each other. It’s like a loaf of raisin bread in the oven. As the loaf rises and expands, the raisins move away from each other. They’re not traveling through the loaf of bread. They’re staying put; it’s the loaf that is expanding and carrying the raisins farther apart.

If space were literally and truly nothing, how could it expand?

Our Universe, apart from the matter and energy (and dark matter and dark energy) it contains, is made of something we call spacetime. Space and time are the components of spacetime. That is why an object’s velocity through space affects the passage of time for that object. Space and time are woven together. If you tug on one you affect both.

The Big Bang created the Universe. But the Big Bang wasn’t something that happened somewhere in space. Before the Big Bang happened, space didn’t exist. The Big Bang created space. And it created Time. It created spacetime.

Suppose you had the power to remove everything from the Universe. You remove the stars, you remove the dust and gas, you remove light and x-rays and gamma-rays. You remove the dark matter and energy. You remove everything, until finally there is nothing left but empty space. And finally, you remove the empty space. Now, what do you have?

You have the situation that existed before the Big Bang. I call it the Void. The Void can’t be pure nothingness, because if nothing at all existed – not matter, not energy, not potential energy, not even some kind of mathematical framework to hang the laws of physics on – if nothing at all existed, then there would be nothing to cause the Big Bang.

If we had a time machine, we could travel back 13.82 billion years to a time when there was no Universe. We’d have to be in a very special time machine that could exist without occupying any space at all, because there was no space to occupy then. There would be no up or down or this way or that way, because those terms describe 3-dimensional space, of which there wasn’t any. Yet. But something happened. We don’t know how it happened, but we see the flotsam and jetsam it left behind. We see stars, galaxies, galaxy clusters, black holes, neutron stars, magnetars, blazars, quasars, and other wonders. We see billions of galaxies. We see a Universe that might be infinite. In fact, there may very well be an infinite number of Universes, each sealed off from all the others, each a part of a vaster Multiverse.

Physicists have theories about how the Universe began and how it may end. In fact, with last year’s discovery of the Higgs boson at CERN, physicists tell us the Universe may well be unstable and that it could collapse into an alternate reality at any time – a reality in which we won’t exist. It may do this, they say, because the vacuum energy is too high. We’re back to thinking about empty space. Empty space is not nothing, it is something, and it is filled with energy. Like water running downhill, the Universe wants to be at a lower vacuum energy than it is now, but it finds itself “blocked” like a river that is dammed in a valley. The Universe is in an “energy valley” and one day it might find a way out. If it does, it will blink out of existence and create a new Universe – a new Big Bang – with a lower vacuum energy.

It’s a lot to think about. Physicists are pretty smart, and they’ve got some really nice tools these days, so maybe they’re right about this. Still, I think they have as much of a shot at understanding the Universe as the ants in my yard have of understanding the plumbing in my house. The more answers we find, the more questions we have. If a Creator exists, it’s a cinch that He’s a lot more clever than us. For sure, the ultimate answers to “Life, the Universe, and Everything” won’t be found in a book.