X-Message-Number: 9243 From: Thomas Donaldson <> Subject: Re: CryoNet #9238 - #9239 Date: Wed, 4 Mar 1998 23:56:43 -0800 (PST) Hi everyone! Well, Mike! What is this digital business and why is it important? I even gave you a reference to a paper in which a machine was described which was PROVABLY not a Turing machine (a neural net with incommensurable lengths of message-paths between nodes). What did you think of it? You must have reasons to brush off something like that so easily. Moreover, in what way is being digital important to understanding how we work? Sure, we need to know how we work on lots of levels. But just what do we gain by assuming that on one of these we may be "digital" --- which seems to me to be (simply put) the notion that a good model for how we work on that level would basically have us working always in integers, like a complex collection of cubic blocks on a 3 dimensional surface. Yes, it is useful to model some things in computers, and computers are digital. But our models are models, not the real thing. And if the connections between our neurons are incommensurable, then we probably can't be modelled by Turing machines. This is not a disaster, it simply says we have to use other models. It does not require much ingenuity to provide such models. As you may remember me saying on other occasions, I have no problem with the idea that we may somehow and someday construct a "brain" capable of the same kind of thinking that we do and the same kind of perceiving, too. But I think we are on very shaky ground if we blithely assume that this "brain" will be a digital computer of any kind. I will make that a much stronger statement: a very good way to misunderstand completely how humans or other animals work is to assume that their brains act like computers. Sure, some parts of our brains can be modeled with computer models, but the model is not the thing. I look forward to your answer. Best and long long life to everyone, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=9243