RE: Measure, madness, and Max

From: <hal.domain.name.hidden>
Date: Mon, 18 Jan 1999 22:48:08 -0800

I disagree with the reasoning of Jacques Mallah regarding quantum suicide.
Jacques claims that in a Many-Worlds universe, someone has no reason
to expect the results of a suicide attempt to be different from what
they would be if there were just one world. I and many other people
argue, instead, that in a MW universe, suicide would eliminate you from
some successor "branches", but that you would go on living in others.
Since you cannot experience your own nonexistence, those successor
branches where you do not exist are irrelevant to you (just as are
branches where all life is impossible). Your personal experience is
that the suicide never works.

(Of course this prediction is completely different from in a single-world
model, where the outcome would be that you continue to remain alive in
the single world with some probability, or that you completely cease to
exist, forever and completely.)

As with many of us, I conceived of these ideas independently. For me
it was when I was in college, about 25 years ago.

There are a number of points on which I believe we can agree:

 - When you attempt a quantum suicide, you remain alive in some
   branches but die in others.

 - The measure of those branches of the world in which you are alive
   afterwards is less than the measure of the branch in which you
   attempted the suicide.

 - In some branches where there are continuations of your present
   existence, you live forever. However the measure of these branches
   is very small.

These depend implicitly on a certain flavor of the MWI, to wit:

 - The universe is composed of multiple distinct worlds, each of which
   is continually branching into multiple daughter worlds.

 - A person's consciousness splits when the universe splits (just like all
   the other parts of the universe do). Each person has continuations
   which are the future versions of themselves, which are separate
   consciousnesses in each daughter branch of the universe.

Jacques also makes another point, which I find somewhat questionable but
which may be valid:

 - Our current conscious experiences can be taken to be "typical" in
   that they are drawn randomly from the set of all of "our" conscious
   experiences, over all the universes.

I question this for a couple of reasons:

 - This is similar in flavor to the Carter-Leslie "Doomsday" argument which
   says that we are typical specimens from the entire history of our race,
   and hence the human race is likely going to die out in a few hundred
   years. This argument is not at all well accepted among philosophers.

 - In the MWI example, it's not clear whether I should be a random sample
   among all instances of "me", or perhaps I should be a random sample
   among all conscious observers in all the universes, human, alien, or
   other. It seems harder to draw conclusions in the latter case.

Jacques has suggested that if you were going to live forever, this last
argument would predict that you would already find yourself very old
(exactly what is predicted with regard to the human race in the Doomsday
argument). However if we assume that the measure of those branches in
which you live forever is small (as it almost surely would be), then
in fact the observation that you are relatively young is consistent with
there being branches where you will live forever.

I would be interested in hearing to what extent Jacques (or anyone
else who disagrees with the conclusion of the quantum suicide argument)
agrees with the various points above.

Hal
Received on Mon Jan 18 1999 - 22:59:16 PST