Slashdot is commenting today on an article by Martin Rees which discusses
the multiverse,
http://www.edge.org/documents/archive/edge116.html.
One point Rees made is the same one that Paul Davies got upset about in
the recent NY Times article discussed here,
http://archive.nytimes.com/2003/04/12/opinion/12DAVI.html. That is the
conclusion that we might very well be living in a simulation, if among
the multiverse are universes which run computational simulations of
other universes.
Maybe there is no well-defined "fact of the matter" as to whether we
are actually living in a "real" universe, or in a simulated one, if
infinite numbers of both exist. However what would happen is that to
get the measure of a universe, we would add together the measure of the
universe itself (perhaps based on Kolmogorov complexity), plus measure due
to additional copies of the universe being simulated in other universes.
We might also assume that simulations would be preferentially focused on
"interesting" universes, especially those where life evolves, and even
more those where intelligent life evolves and does interesting things.
The net effect is that those universes get a sort of boost in their
measure. I'm not sure how large it would be.
How would you relate the measure due to the base-level computation of a
"real" universe against the measure of a simulation of that same universe
as part of another universe? Are they equal, since both run the same
program? Does the simulation get reduced by a factor due to the measure
of the universe that hosts it? And is there a further reducing factor
due to the simulation using only a tiny fraction of the resources of
the host universe? It's not clear how to answer those questions.
However if we take the first view, that all computations are equivalent,
then this could be a very strong, indeed overwhelming effect. The measure
of intelligent-life-containing universes would be vastly greater than for
those which are unconscious. Intelligent life could and would conspire
to make itself more common in the multiverse.
Hal Finney
Received on Wed May 21 2003 - 03:27:23 PDT