Don't Stop Believin'

It's been Christmastime on the ol' internets for the Friar: Hard on the heels of the über-geeky odds of your existence article from a couple of days ago comes this piece by Alan Lightman about the problems the idea of a multiverse poses for scientific inquiry (recommended Lightman work: Dance for Two. Einstein's Dreams a close second).

You should read the whole thing, but here's the box score. There are a lot of different forces and situations that make up the universe, and the more physicists have studied them, the more they have found out that if some of those forces were a little bit stronger or a little bit weaker than they are, the universe would not exist. Or life might not exist in it. The name given to this set of coincidences is usually the anthropic principle, and it has strong and weak versions. The strong version is that these things are the way they are because God (or some other being) set them all that way with the purpose of making a universe that would produce us. The weak version is that those things are all that way because if they weren't, neither we nor anyone or anything else would be around to know about it. There are all kinds of ranges in between; I lean towards a stronger version myself but not as far that way as I described above.

Well, one of the things that scientists have thought, Lightman says, is that because the universe is the way it is, we can get to the basic principles that make it go and we can then understand it in purely physical terms. No supernatural beings or forces required. We read articles about this every now and again, like the recent flurry over possibly tracking down the Higgs boson within the next few months. Or some other advancement that brings us closer to theories that describe all the forces in the universe, sometimes called the Theory of Everything or ToE.

Some of the theories of how the universe was created, though, have brought problems to that idea. Theories that involve concepts like eternal expansion (the universe keeps expanding and never stops) and superstrings (I got no idea, certainly not one brief enough for a descriptive parenthetical aside) also suggest the possibility that other universes exist besides ours -- hence the name multiverse. In these other universes, the physical laws that have governed ours might be a little different and those important forces mentioned earlier might be those few percentage points off that makes the other universes empty and dead.

We have no idea how many other universes there might be, and we have no way to verify their existence experimentally. We probably never will -- we may verify some aspects of the eternal expansion or superstring theory experimentally and if verified those things might imply a multiverse, but there's no way to know for sure.

In other words, a key facet of the creation of everything that exists just might have to be...taken on faith. And I know I've heard that before.