Why Does the World Exist?: An Existential Detective Story by Jim Holt Page A

involves no spacetime, no container or stage or arena of any sort. When we talk about “it,” we’re not taking about any kind of object; we’re merely talking about one of the various ways reality might have turned out—a way neatly captured by the formula
    ( x ) ~ ( x = x ).
    And this formula is not itself part of the Null World—absolutely nothingness would forbid that! It is merely our way of referring to the Null World, of logically encoding what it means for nothing whatever to exist.
    Logical consistency is a great virtue. But it’s not the only virtue possessed by the Null World. Nothingness is also, as Leibniz was the first to point out, the simplest of all possible realities. Simplicity is greatly prized in science. When rival scientific theories are equally supported by the evidence, it is the simplest of them—the one that postulates the fewest causally independent entities and properties, the one least susceptible to a trimming by Occam’s razor—that scientists favor. And this is not just because simpler theories are prettier, or easier to use. Simplicity is held to be a marker of intrinsic probability, of truth. It is complex realities that are thought to stand in need of explanation, not simple ones. And no possible reality is simpler than the Null World.
    The Null World is also the least arbitrary one. Having no objects at all, its census is a nice round zero. Any alternative world will have a nonzero census. It may contain a finite number of individuals, or it may contain an infinite number. Now, unless you are a numerologist, any finite number is bound to look arbitrary. Our own universe, for instance, seems to consist of a finite population of elementary particles (the number of which is estimated to be around 10 followed by eighty zeros). In addition, there may be nonphysical individuals hanging around, like angels. If you added all these objects up, the total census of the actual world would look like a very long odometer reading on your dashboard—lots and lots of arbitrary digits. It would seem just as arbitrary if the world contained a smaller number of objects, like seventeen. Even an infinite world would be arbitrary. For there is not just one size of infinity, but many sizes—infinitely many, in fact. Mathematicians denote the different sizes of infinity by using the Hebrew letter aleph: aleph-0, aleph-1, aleph-2, and so on. If our own world turns out to have an infinite census of objects, why should it be, say, aleph-2 rather than aleph-29? Only the Null World escapes this kind of arbitrariness.
    What’s more, nothingness is the most symmetrical of realities. Many things, like faces and snowflakes, are symmetrical in a limited way. A square has lots of symmetries, because you can flip it about an axis or rotate it by ninety degrees without altering its form. A sphere has still more symmetries: any rotation at all leaves its form unchanged. Infinite space is more symmetrical yet: you can rotate it, reflect in a mirror, or shift it in any direction without changing it a bit. Our own universe is not very symmetrical on a small scale—look at what a mess your living room is! On a cosmic scale it’s more symmetrical, appearing pretty much the same whatever direction you look in. But no universe, our own included, can compete with nothingness in this respect. The Null World’s utter lack of particularity makes it utterly invariant under any kind of transformation. There’s nothing to shift or reflect or rotate. Fearful symmetry, indeed!
    But what sort of virtue is that? Well, it may be an aesthetic one. From the time of the Greeks, with their emphasis on balance and order, symmetry has been deemed a component of objective beauty. That is not to say that the Null World is the most beautiful one (although it may be to those who prefer minimalist decor or have a taste for desert landscapes). But it is the most sublime. If Being is like the blaze of the noonday sun, then nothingness is like