# Re: How To Live In A Simulation

From: Lee Corbin (lcorbin@ricochet.net)
Date: Sun Mar 18 2001 - 23:33:06 MST

If the laws of physics as we know them today are correct, then
"this" has to be a simulation, yet in addition also has to be the
real thing.

First, the denotation "this" is a pointer, but a pointer to more
than one instance. The instances need not be completely
identical, but merely indistinguishable from some perspective. For
an elementary example, you (a) can't be certain that your brain
isn't in a jar in Moscow, nor (b) be certain that (in the
simulation in which you are reading this) there is nothing beyond
the walls of your room, nor (c) can be certain that this isn't the
conventional "real thing", nor, most importantly, can you be sure
that not all three are true at once!

I believe that all three are true by necessity. If you haven't
Deutsch's "The Fabric of Reality". As everyone should know, David
Deutsch, who is a founder of quantum computation, makes a case for
MWI that cannot be ignored.

Although his book is filled with a number of suggestive phrases,
what is missing---and what perhaps no one has yet supplied---is a
quasi-mathematical model that enables us to coherently speak about
the many-worlds, and the overall density or probability of events
in the multiverse. We are left with equating "improbable" with
"has a low density or measure among the many-worlds". In fact, I
have recommended for many years the "Many Worlds Normalization
Principle", which says that there are almost no moral or
psychological consequences that follow from one's realization that
one's self is really multiple copies living in multiple worlds.

Robin Hanson pointed out to me in 1989 the first of just a few
exceptions to the Many Worlds Normalization Principle that I know
of. His exception we call "you can't beat the odds", which
refers, for example, to the following scenario: if the a priori
odds of something bad happening to you are .9, then even after
you've experienced the .1 escape, you must still admit that in
most worlds, the bad thing happened to you anyway.

Regarding the simulation that we are living in: if it is a
simulation, then it is identical to an actual sheaf of worlds in
which the situation arose by the usual laws of physics unmediated
by any simulator. Since these are identical from your
perspective, you might as well regard yourself living in a real
world; but it's equally true that you are living in simulations
too. I think that Nick Bostrom's calculations in

http://www.nickbostrom.com/Simulation.doc are correct, or at least
the spirit behind them is correct, because each of the other
worlds also has a propensity to develop simulation techniques.
(This is an example of the Many Worlds Normalization principle:
in this case, the existence of many worlds does not change the
quantitative picture.)

What does change is that regardless of all the simulations, you
are living in a bottom-level reality too.

Lee Corbin

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