Why is there something rather than nothing? That’s the question that Jim Holt sets out to explore in his new book Why Does the World Exist? The book is a sort of cook’s tour of what might be considered the ultimate question in philosophy and cosmology. Between friendly visits to modern thinkers at home and abroad, Holt provides nifty summaries of the views of Schopenhauer, Leibniz, Aristotle, Sartre, and other opinionated dead humans.
I’d call the book a romp, but it’s rather heavy sledding for a romp. Nonetheless, it’s a good read. The fact that the question is unanswerable — well, the journey is the important thing, not the destination. It’s amusing to watch humanity’s deepest thinkers fall on their keesters, I’ll say that.
One of the issues that Holt hasn’t yet addressed (tonight I’m only halfway through the book) is this: Why should the universe be constrained by the rules of logic? Isn’t it a bit silly to try to tackle ultimate questions using logic, when you haven’t established that logic itself is applicable to these questions?
Another tangle that he hasn’t yet picked apart is the question, what do we mean when we say “thing”? Or, for that matter, “cause”? These words have obvious relevance within the sphere of ordinary human activity; that’s why we use them. But is it possible to say, as he does at some point, that the universe consists of a finite number of things? I claim that it’s not. Not even an “elementary” particle can be considered a “thing” in the way that we ordinarily think of things. And not just because particles are constantly being annihilated in collisions with other particles, which of course would make their number uncountable no matter how keen-eyed the observer. The problem is deeper than that.
We tend to think of elementary particles as if they were little billiard balls. We talk about forces acting on the particles, rather as if the little billiard balls were being struck with the tips of billiard cues and being shoved this way and that, or bouncing off the rails so that they can’t travel any further in a given direction. But if you think about it for a few seconds, you’ll realize that this is absurd. Why is it that a given particle should be constrained to respond to any given force? This question is unanswerable: It provokes an infinite regress. In order to explain why, say, a given electron responds to gravity, we have to posit some other force that leaves it no alternative but to respond to the gravitational force. And why should it have to respond to this second force? A third force would be required to restrict it in that manner. And so forth.
A better way to look at elementary particle physics, I suspect, would be to say that what we call particles exist only in relationship to one another. The “forces” describe their relationships — and at every moment, every particle has an infinite number of relationships, because it’s tangled in “forces” arising from every other particle in the universe.
In other words, the universe is only one “thing.” We think of it as consisting of innumerable separate “things” (stars, sea urchins, whatever) because that’s what our mental equipment is set up to perceive.
I’ve heard that Einstein once said, “The most incomprehensible thing about the universe is that it is comprehensible.” In other words, we’re able to discern what seem to be invariant physical laws — but there seems to be very little rhyme or reason for the existence or pattern of those laws. Attempts to derive all of the observed laws from a single principle that obtained at the moment of the Big Bang — and this is a hot topic in physics, I believe; it’s called symmetry breaking — don’t really address the underlying question at all. Even if all of the observed laws can ultimately be derived, using mathematical models, from a single principle, why on Earth (so to speak) should the universe ever have been constrained to adhere to the tenets of a mathematical model? What force compels the universe to adhere to the laws of physics as we understand (or hope to understand) them?
This is a very troubling question. If you ask me, it’s more troubling than the question, “Why is there something rather than nothing?” The latter question, in beginning with a “why,” implies the existence of causation as a coherent and relevant principle that can safely be applied to big questions about the universe. What I’m asking, among other things, is this: On what basis, other than the merely pragmatic basis that this is what we seem to observe, dare we assert that the universe is constrained by anything that can be described as causation? Until causation itself has been nailed down (using logic? why should logic apply?), we’re not in a position to ask the big “why” questions.