Re: Measure, madness, and Max

From: <hal.domain.name.hidden>
Date: Thu, 21 Jan 1999 10:09:58 -0800

Gilles HENRI, <Gilles.Henri.domain.name.hidden>, writes:
> I'd like to insist again that there is no precise meaning of the question
> whether "you" exist or not in some world. The notion of identity exists
> only because of your memory, and implies a sufficiently classical evolution
> of the world for this memory to be conserved. This is a problem for QS,
> which I did not realize at once. The branching event following a quantum
> measurement is by far the most rapid event we can conceive, since its
> duration decreases exponentially with the number of particles. This is much
> more rapid than any "mechanical" process like the triggering of a gun
> (unless you could realize a vacuum instability that would propagate at the
> speed of light and destroy the whole observable universe. Does anybody know
> how?).

It's not clear that branching is an "event" as such. It is more of a
process, a constant, continual process of splitting.

> So before tempting any suicide, you are already split in two (or
> more) components. For the part of you that has been branched on the wrong
> way, the suicide attempt has almost no chance to transport" or couple you
> to the "right " world. It will couple you most probably to a universe
> compatible with
> 1) your own survival and 2) with the greatest measure.

I see identity in a larger sense. Consider the example proposed
by Jacques, where the universe is infinitely large, and there are an
infinite number of exact, perfect, indistinguishable copies of me spread
throughout the universe. (Each of those copies exists within a region
of space, billions of light years across, which is observationally
indistinguishable from our own.)

I would consider "my identity" to encompass all of those beings, infinite
in number, whose mental states are exactly the same as my own. There is
no meaning to the question, "which one am I?" All of us think that in
unison.

Or consider Wei's experiment, where we have an intelligent computer program
and it is running synchronized on two computers. I would say that the
identity of the computer program is instantiated equally on both
computers.

Now, suppose in the computer case that we flip a coin, and we will give
one of the computer programs a bad experience, and one of them a good
experience. We flip the coin and it turns out that the computer on the
left will get the bad experience. However, it has an automated system
which, upon seeing the coin flip, automatically shuts off that computer.
The computer program itself is not aware of the results of the coin flip.

This is analogous to quantum suicide where you have arranged an automated
system to kill you when something bad happens (say, you failed to win the
lottery), but before you become aware of the result.

We would probably agree that the consciousness of the computer will
never experience being shut down. I would further say that there is no
change in its experience from the shut down; as far as its consciousness
is concerned, it always experiences the good result from the coin flip
and never the bad result.

It is not a matter of consciousness "transporting" from one computer to
the other. Rather, with both computers in identical states, there is
nothing to distinguish one computer's instantiation of consciousness
from the other's. The consciousness is not aware of how many computers
it is instantiated on. So when one stops, it makes no difference.

> It may be a universe
> where you survive miraculously without sequels, or one where you are
> severely injured and where you may not like to live!. It may also be one
> where "you" lost totally the memory of your past, because the worlds where
> this condition is satisfied have a measure null or negligible. so in some
> sense "you" is no more "you". So if you know that the gun is going to be
> triggered, for example by some alarm; it would be a good idea to stop
> immediately this experiment...If you are not convinced, what do you think
> of a "delayed" suicide experiment where you wait for one day before
> triggering the gun?

At any given time, what you will experience is among the least unlikely
events which allow you to stay alive, and which are consistent with your
conscious state. If you don't know what the results are of the lottery,
and if your suicide machine is sufficiently reliable, then the least
unlikely event is that you won the lottery. If you know that you didn't
win the lottery then the least unlikely event may be some of the outcomes
you describe: the suicide machine may break; you may turn out to be insane
(this is the outcome in Greg Egan's novel Permutation City); you may be
injured rather than killed, etc.

Hal
Received on Thu Jan 21 1999 - 10:21:05 PST