Re: being inside a universe

From: Bruno Marchal <>
Date: Thu, 4 Jul 2002 16:07:42 +0200

At 10:28 -0700 3/07/2002, Hal Finney wrote:
>On Thu, Jun 27, 2002 at 03:59:49PM +0200, Bruno Marchal wrote:
>> Now, and we have discussed this before, I have no understanding of the
>> expression "being inside a universe".
>Isn't it necessary to back up here, and to first define what is a
>universe? And then, what does it mean for something (not a conscious
>observer) to be inside a universe? And only then to ask what it means
>to be a conscious observer inside a universe, which I think is what
>Bruno was getting at?
>If we adopt a simple Schmidhuber formulation, a universe corresponds
>to the output of a computer program.

Or try this nuance: an universal story corresponds to the *running* of
a computer program.

>Every computer program creates a

In a very large sense of the word "universe". Perhaps a little too large
sense imo.

>In general, universes are created by more than one computer
>program. The measure of a universe is proportional to the number of
>computer programs which create it.

Glad you say so. This is *not* true for Schmidhuber and those who
keep an absolute interpretation of the SSA (cf Bostrom Self-Sampling
Assumption). Big and slow programs are discrimate away by Juergen,
I argued this cannot be done a priori.

>Obviously most computer programs will not create "interesting" universes.
>I have been reading Wolfram's book A New Kind of Science. He shows
>that programs tend to generate one of four different kinds of output:
>simple, repetitive, random, or structured. Only the last category
>create outputs that we might recognize as a universe like our own, one
>with persistent structure and potentially complex dynamics. The other
>categories would produce "universes" that have no meaningful structure
>and which we can ignore.

Wolfram ignores the distinction between first and third person point of view.
Look for works by Svozil and Rossler for physicist-based motivations
for a similar distinction (named exo and endo physics by Rossler).

>Asking whether something is inside a particular universe means asking
>whether this "something" corresponds to a structure which exists in the
>output of the program that defines the universe. Somewhere there is a
>program which defines our own universe, and if we look at the output of
>that program we would see structures corresponding to atoms, to planets,
>to galaxies, etc. We can then say that these objects exist inside
>that universe.

I don't think we can look into an "output" in that way. For the same
reason we cannot look at your sleeping brain for seeing if you are
dreaming about a banana. This is again linked to the 1/3 distinction.

>Then we can apply the same rule to conscious observers. We can define
>a conscious observer as a particular computational structure, and if we
>can locate such a structure inside the program output that corresponds
>to a universe, then we can say that the observer is inside that universe.
>This seems to be a much more naive and literal interpretation of the all
>universe model than what most of our contributors have been discussing
>lately. Are there flaws in this simple formulation which require a more
>subtle approach?

I would say the flaws are both in the too much static view of a computer
output programs, where I think "universe" are first person emergent on the
running of all computations.

Received on Thu Jul 04 2002 - 07:04:03 PDT

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