How many of you like HP41C calculators?

From: Brian L. Stuart <blstuart_at_bellsouth.net>
Date: Thu Nov 20 23:36:34 2003

der Mouse wrote:
>> But is not LIFE on the molecular level some thing like a bunch
>> computing machines that computes structure rather than logic.
>
> Something like, maybe. But since chemical interactions involve
> randomness randomness coming from the underlying quantum mechanics and
> thus being, as far as we can tell, true randomness...nothing
> deterministic is an accurate model.

To make another semi-random connection here, von Neumann was
very into the emergent behavior of simple automata known as
cellular automata. IIRC he was the first to prove that there
existed self-replicating CAs.

> And that includes nondeterminstic Turing machines, as I studied them,
> since they don't pick one possible transition randomly but instead take
> all possible transitions (which is why the power set construction works
> to determinize such a machine).

Interestingly there does exist a model called a probabilistic automata
that operates in just that way. In fact, if you define what accept
means the right way for the model, it can be shown that there are
non-Turing
languages that can be accepted by a PA.

Brian L. Stuart
Received on Thu Nov 20 2003 - 23:36:34 GMT