[Crito]

> I know that he disagrees the human mind is bound by physical laws.

Last I heard, Penrose appeals to quantum woo to claim that the human mind isn't strictly algorithmic. But sources of quantum randomness isn't enough to push you into dualism, quantum shit is part of our physical universe and while there is no proof that the human mind critically exploits quantum phenomena for it's computation, we can certainly build machines that have RNGs exploiting quantum randomness.

[cbennett]

> Penrose appeals to quantum woo to claim that the human mind isn't strictly algorithmic.

Penrose doesn't appeal to quantum woo, he has a quite well articulated set of assumptions and arguments , related to loop quantum gravity [1], about how objective collapse of the wave function may occur at bio-physically feasible decoherence times.

Now, whether you think his biophysical theories of consciousness are valid, or even required (whether you buy the microtubules argument/hypothesis), is one thing. But stating that Penrose- arguably the 20th century's foremost mathematical physicist- is a practicioner and/or a spreader of 'quantum woo'-- that belies a level of mis-informantion so catastrophically high that it renders your quoted statement indistinguishable from a pure ad-hominem.

[1] https://www.wikiwand.com/en/Loop_quantum_gravity

[cbennett]

@Chronos (can't reply for some reason, so I'm just replying to my own post and tagging you)

Its true that LQG is not known a natural schema to implement hyper-computation. However, since we don't well understand the time-dynamics of twistors ( how these operators may interact non-linearly through time), i don't see any a-priori reason why it is not a possible scheme for super-computation (you could make a good counter- response based on occam's razor, which I'd grant).

Look, lots of thereotical CS folks get disturbed by the idea of hyper-computation/super-turing machines, but in truth Turing machines are a toy model in comparison to true physics; as such, it doesn't take a whole lot more to get something more powerful; Siegelmann and colleagues have shown that real weighted, analog recurrent nets have super-turing abilities [1] [2]. While Aaronson and other raise good questions about physical realizability of such systems, a good thing to keep in mind is that these discussions often take place at computational 'limit' cases, eg solving intractable PSPACE problems, which may not be as relevant to more pedestrian problems solvable by biological systems. Central point: dynamically evolving systems iteratively exploring through (from) in-consistent systems towards more and more consistent ones have many of the same compelling qualities we would call 'super-turing'. Also see the lit on evolving turning machines.

Finally, while I don't agree with the magnitude your Pauling analogy, I certainly agree with you statement that Penrose is out of his depth here. While I do not , presently, buy his argument that quantum effects are necessary to realize consciousness, I remain open to the idea until we know more about BOTH physics and computation.

[1] http://www.mitpressjournals.org/doi/abs/10.1162/NECO_a_00263 [2] http://www.kurzweilai.net/super-turing-machine-learns-and-ev...

[Chronos]

LQG is not believed to allow hypercomputation, i.e. the solving of Turing-uncomputable problems. Penrose's entire argument is based on the idea that the human brain is a hypercomputer, which is why it cannot in principle be simulated by a computer (or any other machine).

It's worth noting that Penrose's field of expertise is General Relativity, not quantum physics, and definitely not Computer Science / philosophy of computation. I see the situation with Penrose as equivalent to Linus Pauling's unfortunate foray into Vitamin C pseudoscience late in his life.