This is rather as if you imagine a puddle waking up one morning and thinking, “This is an interesting world I find myself in—an interesting hole I find myself in—fits me rather neatly, doesn’t it? In fact it fits me staggeringly well, must have been made to have me in it!” This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it’s still frantically hanging on to the notion that everything’s going to be all right, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch-out for. We all know that at some point in the future the universe will come to an end, and at some other point, considerably in advance from that but still not immediately pressing, the sun will explode. We feel there’s plenty of time to worry about that, but on the other hand that’s a very dangerous thing to say. Look at what’s supposed to be going to happen on first of January 2000—let’s not pretend that we didn’t have a warning that the century was going to end! I think that we need to take a larger perspective on who we are and what we are doing here if we are going to survive in the long term.
There are some oddities in the perspective with which see the world. The fact that we live at the bottom of a deep gravity well, on the surface of a gas-covered planet going around a nuclear fireball 90 million miles away, and think this to be normal, is obviously some indication of how skewed our perspective tends to be, but we have done various things over intellectual history to slowly correct some of our misapprehensions. Curiously enough, quite a lot of these have come from sand, so let’s talk about the four ages of sand.
From sand we make glass, from glass we make lenses, and from lenses we make telescopes. When the great early astronomers, Copernicus, Galileo, and others, turned their telescopes on the heavens and discovered that the universe was an astonishingly different place than we expected and that, far from world being most of the universe, with just a few little bright lights going around it, it turned out—and this took a long, long, long time to sink in—that it is just one tiny little speck going round a little nuclear fireball, which is one of millions and millions and millions that make up this particular galaxy and our galaxy is one of millions or billions that make up the universe, and that then we are also faced with the possibility that there may be billions of universes, that applied a little bit of a corrective to the perspective that the universe was ours.
I rather love that notion, and, as I was discussing with someone earlier today, there’s a book I thoroughly enjoyed recently by David Deutsch, who is an advocate of the multiple-universe view of the universe, called The Fabric of Reality, in which he explores the notion of a quantum multiple-universe view of the universe. This came from the famous wave/particle dichotomy about the behaviour of light—that you couldn’t measure it as a wave when it behaves as a wave, or as a particle when it behaves as a particle. How does this come to be? David Deutsch points out that if you imagine that our universe is simply one layer and that there is an infinite multiplicity of universes spreading out on either side, not only does it solve the problem, but the problem simply goes away. This is exactly how you expect light to behave under those circumstances. Quantum mechanics has claims to be predicated on the notion that the universe behaves as if there were a multiplicity of universes, but it rather strains our credulity to think that there actually would be.
This goes straight back to Galileo and the Vatican. In fact, what the Vatican said to Galileo was, “We don’t dispute your readings, we just dispute the explanation you put on them. It’s all very well for you to say that the planets sort of do that as they go round and it is as if we were a planet and those planets were all going round the sun; it’s all right to say it’s as if that were happening, but you’re not allowed to say that’s what is happening, because we have a total lockhold on universal truth and also it simply strains our personal credulity.” Just so, I think that the idea that there are multiple universes currently strains our credulity, but it may well be that it’s simply one more strain that we have to learn to live with, just as we’ve had to learn to live with a whole bunch of them in the past.
The other thing that comes out of that vision of the universe is that it turns out to be composed almost entirely, and rather worryingly, of nothing. Wherever you look there is nothing with occasional tiny, tiny little specks of rock or light. But nevertheless, by watching the way these tiny little specks behave in the vast nothingness, we begin to divine certain principles, certain laws, like gravity and so forth. So that was, if you like, macroscopic view of the universe, which came from the first age of sand.
The next age of sand is the microscopic one. We put glass lenses into microscopes and started to look down at the microscopic view of the universe. Then we began to understand that when we get down to the subatomic level, the solid world we live in also consists, again rather worryingly, of almost nothing and that wherever we do find something it turns out not to actually something, but only the probability that there may something there.