[ExI] Some new angle about AI

[The Avantguardian]

----- Original Message ----
> From: Stathis Papaioannou <stathisp at gmail.com>
> To: scerir <scerir at libero.it>; ExI chat list <extropy-chat at lists.extropy.org>
> Sent: Tue, December 29, 2009 4:01:54 PM
> Subject: Re: [ExI] Some new angle about AI

> > We can find "uncomputability"  in quantum physics (i.e. essential randomness,
> > contextuality, etc.) but also in classical physics. So it is possible that the
> > brain does in fact utilise, in a technical meaning, uncomputable physics.
> > Speaking of elaboration of information by the brain (here supposed to be a
> > complex quantum system), according to a speculation the mind/brain might 
> encode
> > "propositions" in quantum states, and then might "measure" these quantum 
> states
> > to test the "truth values" of the propositions. Random outcomes given by
> > measurements associated with the propositions should mean that the "truth
> > values" are uncertain, that is to say that the propositions are undecidable
> > (within the context of that mind/brain, and its stored information). But it is
> > just a speculation.
> 
> We can compute probabilistic answers, often with high certainty, where
> true randomness is evolved (eg. I predict that I won't quantum tunnel
> to the other side of the Earth), or we can use pseudorandom number
> generators. I don't think anyone has shown a situation where true
> random can be distinguished from pseudorandom, but even if that should
> be a stumbling block in simulating a brain, it would be possible to
> bypass it by including a true random source, such as radioactive
> decay, in the machine.

> By uncomputable I was thinking not of randomness but of solving
> undecidable problems, such as the halting problem. Quantum computers
> can't do that.

I appreciate that you accept that possibility that the brain may be uncomputable so I won't belabor that point. But randomness is not as cut and dry as you seem to think. The only measurable difference between randomness and predetermined chaos seems to be a priori knowledge of the system dynamics. Furthermore chaos theory, essentially an uncomputable branch of classical physics as suggested by Serafino, blurs the distinction between randomness and undecidability by recursion.
 
For example Conway's "Game of Life" is undecidable at high iterations despite using a very simple set of rules which could be considered to be a canon of physical law in the greatly simplified microcosm of the game. In other words, based on an initial configuation of pixels the only way to determine whether the resultant pattern will stabilize as an infinite loop or go "extinct" is to actually run the program and see what happens.
 
Similarly despite the fact that fluid turbulence is known to be governed by the Navier-Stokes equation, turbulent flow is similarly uncomputable.. This is the main reason why long-term weather prediction is not currently possible and why one cant predict the shapes of clouds or the dispersion patterns of fallen autumn leaves. These are all *deterministic* systems yet the mind is so boggled by the recursive complexity and sensitivity to initial conditions thereof that it hides its ignorance under the security blanket of *randomness*.     


Stuart LaForge 


"Science has not yet mastered prophecy. We predict too much for the next year and yet far too little for the next ten." - Neil Armstrong