RE: Devil's advocate against Max Tegmark's hypothesis

From: Marchal <marchal.domain.name.hidden>
Date: Wed Jul 7 07:10:29 1999

James Higgo wrote:

> Let's be clear about the flying rabbit: we have chosen it as a proxy
>for something very unusual. Otherwise we would have said 'flying bat' which
>is unusual but not very unusual. So we are really asking, 'why is something
>we have chosen to be very unusual, very unusual?'. I fail to see the
>relevance of this piece of circular reasoning.
>
> All it amounts to is asking why there is any stability in our
>observations, and I think you need nothing more than the weak anthropic
>principle to explain stability.

You are right James, we need nothing more than the weak
anthropic principle (WAP) to explain stability.

So, here are the questions (which remains!) :

1) You apply the WAP to what ? (there will be very different answers for
the
computationalist, the mathematical structuralist, the quantum ontologist
etc...).

2) How do you apply the WAP ? I guess most of us agree with Nick Bostrom
Self Sampling Assumption. We have discussed why we need the Strong SSA
(wich bears on the "observer instant"),
and we have defended the idea that we should apply a "relative"
SSSA, i.e.the idea that we can only compute the probability of a "next
observer-instant" relatively to a "present" memory or self.

Classical physicist can explain why we don't see boiling water in the
fridge (altough it is statistically possible). And Everett (and his
followers) begin to explain, in the pure quantum realm, the classical
deterministic feature of our *macroscopic* observations.

In the same way, if we want use the WAP as a principle capable of
explaining 'everything', we should extract from it classical
probabilities, quantum probabilities, and (at least with comp) the
hamiltonians.

If you don't do that, you will not convince people. They will
take the WAP for "philosophical ramble" of the kind "the world
is as it is because if it were not it would be different, and because it
is not different it must be like it is" This hardly explain anything even
in the everything exist hypothesis.

You can look at David Lewis' "plurality of worlds" for an independant
account of the *flying rabbit problem* (the inflation of expectations).
David Lewis does not really solve the problem ...

Bruno
Received on Wed Jul 07 1999 - 07:10:29 PDT