hi all. re: t'hooft's paper. I have skimmed t'hoofts recent paper considering a local hidden variable theory for QM. I believe it is identical to a very simple model Ive been developing for years but only recently came up with a nice analogy.
consider a set of speakers and a microphone. let the speakers vary sinusoidally. describing this system mathematically gives rise to a wave equation and a superposition of waves. also, a hilbert space of parameters controlling the speakers. (in t'hoofts paper, this is a set of simple harmonic oscillators) now imagine the microphone is actually a digitizer. now consider the LSB, least significant bit. that bit has a 50% chance of "firing" when a wave passes thru the speaker. but no matter what you do to the setup, you cannot increase this probability. it appears to me the "firing LSB" is analogous to the detection of a photon in quantum theory. now, this is classical physics LHV (local hidden variable) theory totally consistent with QM in a limited domain. why? bells thm supposedly rules out such a construction. the answer is very simple. the hidden variables determine detection probabilities, and may sometimes specify "no event". if you study bells thm very carefully, you will find it cannot rule out this possibility. (note, this is not the same as the detector efficiency loophole noted in the literature.) Ive been promoting this theory on my mailing list: http://groups.yahoo.com/group/qm2/ (am always looking for a good mathematician or qm theorist to collaborate with. would like to write a paper on the subject but havent been able to get the free time so far.)