regarding quantum neural computer announcement

[Paul_Gleichauf@B.GP.CS.CMU.EDU]

Fellow Connectionists,
	Michael Dyer has raised some interesting issues
reminiscent of past discussions that were inspired by Roger
Penrose's book "The Emperors New Mind".  Whether they have 
anything to do with Dr. Kak's paper, or his very sketchy initial
announcement, will require some careful reading.
	I am sure that we want to be a bit cautious about getting
into a debate about quantum computation and its ostensible
relationship to intelligence or consciousness. In particular, the
notion that there exist deterministic equations that govern the
evolution of a pure particle description is subject to very strict
limitations.  One of the problems with chaos based deterministic
equations that might be hypothesized as governing quantum theory
is the assumption that there are  "hidden variables" that evolve 
such systems. The coefficents of the governing equations, which are
so important in chaotic systems, have a very strictly proscribed
role in quantum theory.  These include the prohibition of local
hidden variables as coefficents for such equations. This is a
very tought hurdle for chaotic model of quantum mechanics. There are
papers by J. S. Bell that first breached the issue of the viability
of hidden variables on terms of verifiable experimental predictions
that are in contradiction with those of quantum mechanics.  They,
and other technical references to this subject, are collected in
Quantum Theory and Measurement, Ed. by J.A. Wheeler and W. Zurek,
Princeton University Press, 1983.
	In a useful sense the equations of quantum theory are quite
deterministic, it is just that they determine the development of
wavefunctions which are used to compute the probabilty of
measurements.  The measured results are probabilistic, the
fundamental theoretical building blocks of the theory are not.
	An interesting sidebar is that fairly recent efforts to
prove the computational power of so-called quantum computers has not
expanded the definition of computability beyond Turing machines.
There are some papers which are referenced by Penrose in
his book, and there have been some serious efforts to build some
real devices that test the theory and have produced consistent
results. So if some of us are looking to the quantum to provide more
computational power than Turing's machine, we may either have a much
more fundamental problem to examine, the foundation of quantum
mechanics, or we may be looking to false gods.
	Quantum mechanics really is a theory of probability
amplitudes, and its predictions are consistent with experiments. I
know of no evidence yet that the predictions of quantum mechanics
are not Turing computatable. I regard my own hopes that there are as
romantic notions not substantiated by science. Maybe that is why so
many of us have apparently responded to Dr. Kak's announcement as if
it claims not only the potential of quantum computation to solve
artifical intelligence problems, but the necessity.

							Paul