What’s the scariest thing you can think of? Well, OK, apart from the fact that there’s currently someone stupider than George Bush who has a crack at the Presidency…
How about infinity? The size of the Universe and, if it turns out to be finite, what lies beyond.
Think about it. Lie out flat on your back at the top of a hill on a clear, dark, moonless night, away from street lights/forest fires/your hated light pollution du nuit, and just look straight up. Where does ‘up’ stop?
We know that the black stuff you’re looking at, between all the billion-star galaxies and assorted undiscovered matter, is a mostly-empty void at least 156 billion light-years in extent, and to the best of our knowledge, there’s more of the same beyond. But that’s not what I’m talking about. That’s not what scares me.
What scares me is that there must be something beyond that. And beyond that. And beyond that. Whatever you come up with to explain what’s beyond the known universe, there must be something else beyond the thing you’ve just described. Because if there isn’t, it must be nothing in a way that pure, lightless, gravityless, vacuum with nary a subatomic particle or wave in it is not. And even aside from the fact of its nothingness, how far does it go on for? It must have dimensions, for how else can it contain all the things we can see?
More universes? How many? How big? What’s beyond them? What does the boundary between universes look like? Is there anybody living close enough to such a boundary to see it?
Ah, you might say, but space curves. If you accelerate as fast as the universe allows, eventually – maybe billions, trillions of years later – you’ll arrive back where you started. But there’s a flaw even in this argument. A curve is defined by its boundary, and there can be no defining boundary unless something exists outside the curve to define it. So what’s that? And how big is it? And what’s beyond it? And beyond that… ?
But hey, I just try not to think about it. There are more important things. Like watching the stars, and snuggling under a blanket with my good lady and a fine bottle of wine.