Philosophy Now Forum

by Joel Marks

http://philosophynow.org/issues/98/Nonsense_on_Stilts

Is JM for it, or against it? That ironic ending...

It's ambiguous, isn't it?

The Multiverse Hypothesis was proposed to solve the question, "Why does something exist, rather than nothing?' It's proposed answer is, "Since we live in an infinite universe, all things that can be are."

This answer is wrong. It's premised on a straightforward fallacy.

It assumes that given enough time and space, and hence enough opportunities for contingencies to take place, all possibilities must happen somewhere. Given enough time, the improbable (i.e. our existence) becomes inevitable.

In fact, it must go further, and even presume that the improbable has happened an infinite number of times, and will happen another infinite number (i.e. there are infinite copies of you, running around and living life just as you are; and an innumerable host of creatures *almost* like you, but different in myriad small ways.)

So where's the fallacy? Well, consider this: the number of possible recursions of an event only increases its probability if there are a *finite* number of variables in play.

To see this, consider a six-sided dice. If you put your chips down on "5", you have a 1 in 6 chance of winning. Bad odds. But, says the proponent of the MH, given more rolls, your odds go up: so if you bet on there being a "5" not in one roll of the dice but in 100 rolls, then suddenly that which was improbable, a "5," becomes *highly* probable -- indeed, almost inevitable.

But here's the fallacy: a dice only has 6 sides (a finite number). If it had a hundred sides, your odds of rolling a "5" would still be low in a hundred rolls. Aha, says the MH'er: but there are not a hundred "rolls": there are an infinite number! Infinity is incredibly big, and compared to it, 100 is infinitessimally small. So suddenly a "5" is inevitable again."

Fine. But what if the dice is not 100 sided, but infinite-sided? Then the chance of *any* single number *ever* appearing becomes quite literally, infinitely unlikely.

We are told the universe may be infinite. If so, it contains infinite possibilities. So it's an infinite number of rolls of an infinite dice, with the chance of any particular outcome infinitely unlikely.

So at the end of the MH, we're back to asking "Why does anything exist, rather than nothing" --and adding, "given that the chances against my very existence are infiinite?"

So the MH is a stiff. Don't trouble yourself with it.

Or if you do, use it only as the best reason to ask, "Why am I here?"