Re: Universes with different laws?

From: Marchal <>
Date: Sun Aug 19 09:38:27 2001

Fred Chen wrote:

>The MWI of quantum mechanics (where worlds share common laws and
>characteristics) and the multiverse concept from Tegmark, Schmidhuber, Lewis
>and others ...

An inattentive reading of some of my posts could give the idea
that I (Bruno) belong among the others. To prevent misunderstanding let
me make precise that *in some sense* (explained below) I am closer to
Everett/Deutsch/qm-MWI than Tegmark, Schmidhuber, Lewis.
(Although nuances could be added but I prefer to remain short).

>... (all logically possible universes exist, including those with
>different laws and characteristics)

I believe, like David Deutsch says, that "all
logically possible universe" is a quasi-contradictory notion.
To give a reasonable semantics of *that* "all", you need something
bigger ...

In the comp approach, the "everything" is the running
of all programs,
(which *can* be defined mathematically, and is universal in a sense
deepened by Church Thesis).

The laws of physics are eventually derived
from average possible consistent point of views, and made *necessary*,
The very idea of a "physical universe with other laws" is just

But then any notion of even one universe/multiverse, is given a
phenomenological derivation, without the need to postulate one.

>are very similar, but they are actually
>independent concepts. It is an interesting perspective you bring up where
>all possible universes could actually be MWI-type splittings of a computer
>running a program.

This is common in Schmidhuber and me. But Schmidhuber, to sum up
crudely is like a sort of Bohmian Computationalist, in the sense that
Juergen attachs the "private mind" of the observer to a single
and this just doesn't work with the comp hypothesis, once we take
account of the first and third person (and other point of view nuances)

Of course DD postulate a uni/multiverse from a theory (QM) which
is partly empirically infered.
I infer only the arithmetical truth, but I give an
explanation why sound machines believe in universe(s).

I show that comp leads to idealism (UDA). No problem abandoning comp at
that point. But I don't see a contradiction. Quite the contrary
when I translate the UDA in ``the sound machine language", thank
to the work of Godel, Lob, Solovay,(+ Boolos, Goldblatt, Visser, ...)
I got quantum logic for the description of ``probability 1" on the
UD* indeterminacy domain, so the QM confirms a posteriori comp.

Received on Sun Aug 19 2001 - 09:38:27 PDT

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:07 PST