On Wed, Dec 09, 1998 at 08:12:38PM -0500, Jacques M. Mallah wrote:
On the contrary, it's the same. That is easy to prove: suppose
the MWI was false but assume the universe is spacially infinite, so there
are other people like you in distant galaxies. Clearly they have no
bearing on what you do, so you should make the usual decisions, including
of course any suicide decisions. It is no different in the MWI; the only
difference is that the others are in different parts of wavefunction
configuration space, rather than regular space.
Unfortunately because currently accepted decision theory makes some
metaphysical assumptions, it can be compatible with a spacially infinite
universe but not with MWI. Basicly decision theory depends on the idea of
alternate realities and the notion that an individual chooses the actual
reality among the alternatives as he makes decisions and acts upon them.
But according to MWI, all alternatives are real and have predetermined
measures.
I can't figure out how to apply decision theory with the MWI. If you can,
show us how, and please include an example.
maybe the decision theory itself (I must confess that my only knowledge of
it comes from what Wei writes here) is somewhat metaphysical because it
assumes that an individual can actually change the evolution of the world
(acts upon it). In any model (not only MWI) where human beings are
nothing but rather complicated physical systems, free will is an illusion.
They evolve simply (including in their choices) following the physical
laws. So you can theoretically determine what would be the best choice
following some criteria, but you are never certain that a given physical
system will follow this way. In MWI, you can also calculate a best way, but
you are certain that other ways will be followed as well. In one world
interpretation, you can try to programm a system (or a brain) to maximise
the probability of evolving along a good way, but I think it is also true
in MWI (maximise the number of worlds where the good way is followed).
Gilles