A Computationally Universal Field Computer

[Mitsu Hadeishi]

David Wolpert writes in response to Penio Penev regarding his recently
posted abstract:

>What's quite a bit more difficult is emulating an arbitrary (discrete
>space and time) Turing machine using a neural net with an *uncountably* 
>infinite "memory", and *continuum* dynamics of the signal through
>the net (i.e., signal dynamics governed by differential equations, rather 
>than by discrete time steps).

	I'm interested to know what effect noise or signal degradation
might have on your technique for emulating an arbitrary Turing machine
using your linear field computer.  I would imagine that you would get
some sort of statistical approximation of a Turing machine, for example
you'd have a certain (perhaps quite high) probability of correct
results.  Of course, real physical finite computers have exactly
the same problem, with the potential for memory failures and other
unexpected deviations from theory.  However, I was wondering
to what extent your technique for getting computational universality
was sensitive to noise and whether you addressed this issue in your
paper.

Mitsu Hadeishi
Open Mind