Nagle@cup.portal.com (John - Nagle) (12/26/89)
1. Remember that the physical world has noise. The uncertanty principle limits the precision of any analog simulation. 2. Recent work has resulted in an effective way to solve N-body problems to an arbitrary level of precision and with high speed. See "The Rapid Evaluation of Potential Fields in Particle Systems", by L.F. Greengard, MIT Press, 1988. ISBN 0-262-07110-X. Systems with over a million bodies are now being solved using these techniques. 3. Biological neurons are rather noisy components. If you would like to see this for yourself, stop by the Exploratorium in San Francisco, where a slug neuron has been wired up to a signal source and a scope, and you can play with the inputs while watching the output. The overall behavior of a neural system doesn't seem to be that sensitive to the exact transfer function of each neuron. If it were, of course, brains would be much more fragile than they are. This comment applies to both biological and synthetic neural systems.