Reality in the multiverse

From: Hal Finney <hal.domain.name.hidden>
Date: Wed, 27 Jul 2005 22:43:42 -0700 (PDT)

One problem with "reality" in the context of multiverse theories is that
it may mean different things to different people.

If we assume (for analytical purposes) that some form of multiverse
exists, then ultimately the reality is the multiverse. But it seems that
each person is constrained only to see one universe out of the multiverse.
For him, that universe is all that is real, the rest of the multiverse
is irrelevant. So already there is confusion over whether we should
include the other worlds of the multiverse in "reality".

I have been exploring the concept that the Universal Distribution exists
and is "real". Reality in this model is every computer program execution,
or equivalently (I would claim, but it is not too important here) every
information pattern.

This is a sort of "multiverse", in that it includes multiple "universes".
Anything that can be created by a computer program exists, and arguably
universes fall into this category.

But it also includes other things. Chaotic information patterns
that would not seem to possess most of the properties of a universe
exist as well - without time, or causality, or dimensionality perhaps -
just raw noise.

And disembodied consciousnesses exist, too. We could each have our
information patterns, the processes that make up our minds, be produced by
programs which do not actually create the rest of the universe but simply
contain hard-coded sense impressions which are delivered by clockwork.

The UDist framework allows us to theoretically approximate the measure
of these various information objects, so we can say that some are more
"prominent" in the multiverse than others. But all exist, all are real,
in this model.

One of the points Bruno makes is that in these kinds of models,
the reality for a given observer is pretty complicated. Much of the
multiverse is irrelevant to him, but that doesn't mean he can focus on
just one universe as "real". The observer spans multiple universes and
multiple realities.

In the UDist framework, I would say it in this way: Many programs
create the information pattern corresponding to a given observer.
Some of those programs create the observer as part of a relatively
straightforward universe that corresponds fairly simply to his sense
impressions. Some programs create the observer within a universe that
has a far more subtle and complex relationship to what the observer
senses. In some universes the observer is part of a simulation a la
The Matrix, being run on artificial machines within that universe, so
that what the observer sees has little relation to the "true reality"
of that universe. And some programs create the information pattern as
I described above, without a real universe at all, so that the observer
in effect hallucinates the entire universe.

The point is that all of these programs exist, hence all contribute
measure to the observer. From the observer's perspective, all of these
are in a sense "real" to him. However, he can in principle calculate
(at least approximately) the numerical contribution made by each of
these programs, and perhaps it turns out that the vast majority of the
measure comes from just one of them. He might be justified in that case
in largely ignoring the others and saying that only that one is "real"
for him.

But for full precision he must still take into consideration all of
the programs that could create instances of his information pattern,
and consider all of them to be "real" to some extent. And then, perhaps,
he may choose to accept that the whole multiverse is real, even the parts
which do not affect him. Otherwise he has to say that all programs exist
which happen to include an information pattern corresponding to him,
the observer who is making this claim. That's not a very compelling
theoretical model.

Hal Finney
Received on Thu Jul 28 2005 - 02:37:01 PDT