Re: AUH/MWI/UDA (Was: Everything is Just a Memory)

From: Alastair Malcolm <amalcolm.domain.name.hidden>
Date: Tue, 8 Feb 2000 20:15:38 -0000

----- Original Message -----
From: Fred Chen <flipsu5.domain.name.hidden>

> Can it be argued that the "simplicity" (of QM interpretation,
computational
> implementation) of MWI gives it a larger measure among other
possibilities? Or
> is it the large number of worlds generated by MWI splittings that would do
this?

Russell's paper implies simplicity alone is sufficient, but in case it is
not totally watertight (I am not competent to fully assess this), here is a
(pretty Heath-Robinson) argument showing how splittings might conceivably
contribute:

Suppose the minimum functional bit string length for a specification of
Everett many worlds is n. Then we are comparing the measure of SAS's of all
combinations/interpretations of bits up to n. (Bits above n could 'multiply
up' whatever has been specified below n either via different possible
interpretations, different 'don't care' bit combinations, or direct
'multiplier' bit-string segments, dependent (at least partly) on the
particular version of the AUH chosen. Effectively these factors above n
'cancel through' for all different combinations/interpretations of the first
n bits, and so can be ignored.)

Now, in order to 'out-measure' Everett, a theory would have to produce the
complexity needed for SAS's well *within* the n bits, so that the surplus
bits can be used to outnumber the worlds/SAS's produced in the splittings of
Everett's theory, or else it must itself produce Everett-like splittings
(and SAS's) with less than n bits (that is, with greater simplicity than
Everett). There is little indication where such a theory could possibly come
from.

But if there were some theory of similar simplicity to Everett specifying
SAS's in a single world (say something approaching a good old-fashioned
all-Newtonian universe), then it would be the Everett splittings themselves
that would be responsible for the dominant measure (and explain why we see
interference fringes).

Alastair
Received on Tue Feb 08 2000 - 12:26:18 PST