Re: Predictions & duplications

From: <hal.domain.name.hidden>
Date: Fri, 12 Oct 2001 10:19:19 -0700

Juergen writes:
> Some seem to think that the weak anthropic principle explains the
> regularity. The argument goes like this: "Let there be a uniform measure
> on all universe histories, represented as bitstrings. Now take the tiny
> subset of histories in which you appear. Although the measure of this
> subset is tiny, its conditional measure, given your very existence,
> is not: According to the weak anthropic principle, the conditional
> probability of finding yourself in a regular universe compatible with
> your existence equals 1."
>
> But it is essential to see that the weak anthropic principle does not
> have any predictive power at all. It does not tell you anything about
> the future. It cannot explain away futures in which you still exist
> but irregular things happen. Only a nonuniform prior can explain this.

Isn't this fixed by saying that the uniform measure is not over all
universe histories, as you have it above, but over all programs that
generate universes? Now we have the advantage that short programs
generate more regular universes than long ones, and the WAP grows teeth.

Hal Finney
Received on Fri Oct 12 2001 - 10:46:45 PDT