Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!andante!mit-eddie!bloom-beacon!think!ames!pasteur!ucbvax!DIAMOND.BBN.COM!dm From: dm@DIAMOND.BBN.COM.UUCP Newsgroups: comp.society.futures Subject: Re: The future of AI Message-ID: <8806291531.AA15519@quartz.BBN.COM> Date: 1 Jul 88 14:00:10 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 26 X-Unparsable-Date: 1988-06-29-11:31:19 >Actually, there are an infinite number of turning machines. Turing machines >may have an infinite number of states. In fact, one can argue that, >given the size of a neuron, and the size of a human head, there are a limited >number of neurons that will fit in a human's head, so a turing machine is >capable of more complex behavior then a human. >Michael Wolf Actually, as the person to whom you were replying pointed out, there are only a countable infinity of Turing machines (that is, Turing machines can be put into a one-to-one correspondence with the integers). I'll have to be convinced that there is an uncountable number of problems (seems plausible at first blush, but then, countable vs. uncountable infinities DON'T seem plausible at first blush, so I don't like rely on mere plausibility where levels of infinity are concerned). As regards your second point --- that our finite heads imply there are things we can't conceive --- Rudy Rucker explores this idea in great detail in his _Mind tools: the five levels of mathematical reality_. His meditation is inspired by Gregory Chaitin's algorithmic information theory (``You can't get a 20 pound theorem out of a 10 pound axiomatic system''), which is also described in the June, 1988 _Scientific American_ (in the article ``Randomness in arithmetic'').