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. Every computer program creates a
universe. 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.
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.
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
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