RE: Is the universe computable?

From: Hal Finney <hal.domain.name.hidden>
Date: Mon, 3 Nov 2003 22:23:36 -0800

IMO the best idea we have discussed for why the universe is and remains
lawful is that the set of descriptions (equivalently, programs) for
the universes are governed by the Universal Distribution. This is the
description where a string whose shortest description has length n bits
is given measure 1 / 2^n.

An heuristic argument for this distribution is that if programs are
self delimiting, then there are 2^x more programs of length n+x than
of length n, created by appending the 2^x x-bit strings to each n-bit
program. Since the appended x bits are never executed, all 2^(n+x)
of these programs are the same as the basic 2^n programs.

A program which says "obey these simple laws" is shorter than a program
which says "obey these simple laws for a zillion steps, then start
obeying these other laws", or a program that says "obey these simple laws
everywhere except where this incredibly complicated configuration occurs,
and then do this complicated other thing."

Hal Finney
Received on Tue Nov 04 2003 - 01:25:59 PST