[extropy-chat] Role of MWI and Time Travel (was: Are ancestor simulations immoral?)

[scerir]

Lee Corbin:
Remember that QM under MWI is a completely 
deterministic theory, and that "free will" 
is an awkward concept in deterministic systems.

# I may be wrong - since I don't like Everett's
theory, and MWI, and Many Minds, and even the 
Relational theories by Rovelli, Mermin, etc. - 
but MWI is a deterministic theory in a very specific 
sense.
One can say that the quantum states of QM evolve 
deterministically in time. One can say that Everett's
or MWI Universal Wavefunction evolves deterministically
in time. (There are hints, though, that even this statement
is somehow simplistic, since there are strange cases, 
pointed out, i.e., by David Z. Albert [1]).  
But that has nothing to do with the definiteness
of the predicted outcome of the possible measurement
performable on a specific system while it is in a given 
prepared state. Even within MWI one cannot predict,
in a deterministic way, the definite outcome of the 
possible measurement performable on a specific system 
(leaving apart the peculiar case of the quantum Zeno 
effect, in which there is no branching of worlds).



Russell Wallace:
Physics _has nothing whatsoever to do with free will_. 

# I don't know if physics has something to do with
human free will. The problem seems to be the free will 
of simple systems [2], which is more subtle, since the
Bell - Kochen & Specker theorems [3] aborted the so 
called 'value definiteness' of quantum states. 

s.

[1] Barrett, J. A. and D. Z. Albert (1995) 
"On What It Takes to Be a World" 
Topoi, 14(1): 35-37
http://www.lps.uci.edu/home/fac-staff/faculty/barrett/papers.html

[2] John Conway, Simon Kochen
"The Free Will Theorem"
http://www.arxiv.org/abs/quant-ph/0604079

[3] Kochen & Specker Theorem
http://plato.stanford.edu/entries/kochen-specker/