[MURG] - emulation difficulties

[Mitchell Porter]

>Deterministic differential equations, yes. (And you can safely
>ignore Penrose; he's a reasonably good mathematician but a complete
>moron at neuroscience. He's looking to find God in quantum
>microtubules, and wants it badly enough to discredit himself in the
>attempt.)
>
>
>well, I was referring to his five-fold symmetric crystals that he claimed 
>showed quantum effects at the classical level... I keep meaning to look it 
>up to see if there's any current work or new theories, but I never get 
>around to it

I think the most reasonable version of the microtubule idea is
that electrons delocalized along its length are, on one hand,
sensitive to transient magnetic fields created by the action
potential, and, on the other hand, control tubulin conformation
and thus molecular bonding on the microtubule surface. This
is a way for exotic many-body quantum effects to play a role
in the causal chain. Nancy Woolf at UCLA has some ideas on
how it would all relate to the psychopharmacology of cognition.

Penrose's hypothesis is, not just that the brain is a quantum
computer, but that it's a quantum oracle, in the sense that
Turing defined an oracle - a computer possessing an extra
computational primitive capable of implementing functions
which are not Turing-computable. There are delicate issues
of provability, finitude, rationality, and randomness here
('delicate' meaning I don't personally have a grip on them).
In the case of the quasicrystals, the infinite tiling is not
computable, but finite subpatterns *are*, and since every
real-life quasicrystal you can get at is only of finite extent,
it doesn't really constitute evidence of *noncomputable*
quantum jumps organizing the atoms.

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