Re: "Naive Realism" and QM

From: Brent Meeker <meekerdb.domain.name.hidden>
Date: Sun, 21 Aug 2005 20:55:26 -0700

Russell Standish wrote:
> On Sun, Aug 21, 2005 at 06:12:54PM -0700, Brent Meeker wrote:
>
>>I've haven't read your derivation, but I've read quant-ph/0505059 by VAn
>>Esch which is a proof that the Born Rule is independent of Everett's MWI
>>and cannot be derived from it.
>>
>>How do you avoid Van Esch's counter example.
>>
>>Brent Meeker
>
>
> I'm not sure its that relevant - I don't derive the Born rule from
> Everett MWI per se, but rather from assumption that 1st person
> experience should appear as the result of an evolutionary process. I
> actually use Lewontin's criteria for evolution - I have an improved
> explanation of this in appendix B of my draft book, although
> technically it is identical to the FoPL paper.
>
> Another way of viewing this topic is that the Multiverse (or MWI) is a
> 3rd person description, whereas the Born rule is a 1st person
> property. So it is not surprising that the two are independent.
>
> Looking at the paper, Esch proposes an alternative projection postulate
> that weights all possible alternatives equally, ie it is equivalent to
> the usual PP provided that the state vector is restricted to the set
> of vectors \psi such that
>
> <\psi|P_i|\psi> = 1/n_\psi or 0.
>
> Let \psi' = \sum_i P_i\phi, for any vector \phi, and let
> \psi=\psi'/\sqrt{<\psi',\psi>}, so this set if not empty.
>
>
> This is a kind of all or nothing approach to \psi - \psi contains only
> information about whether x_i is possible, or impossible, but doesn't
> contain any shades of gray. It is saying, in other words, that White
> Rabbit universes are just as likely as well ordered one - something
> that contradicts the previous section on the white rabbit problem.
>
> Instead, I assume that \psi does contain information about the
> liklihood of each branch,

That would be one form of the additional postulate which Van Esch says is
necessary to derive the Born Rule - so there is no conflict with his result.

Brent Meeker
Received on Sun Aug 21 2005 - 23:57:00 PDT