Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!dali.cs.montana.edu!uakari.primate.wisc.edu!aplcen!uunet!dlogics!dsa From: dsa@dlogics.COM (David Angulo) Newsgroups: comp.ai Subject: Re: Artificial vs. ''real'' intelligence Summary: Quite a claim! Message-ID: <600@dlogics.COM> Date: 10 Jul 90 20:05:40 GMT References: <1990Jul2.182411.4441@king.mcs.drexel.edu> Organization: Datalogics Inc., Chicago Lines: 35 In article , tim@cstr.ed.ac.uk (Tim Bradshaw) writes: > I have a paper by Deutch where he proves something he > calls the `physical Church-Turing principle': > > Every finitely realizable physical system can be perfectly > simulated by a universal model computing machine operating by > finite means. > Well, I only majored in Physics in college. I do not even pretend to be an "expert." Also, I haven't read this reference and perhaps you're misquoting it; however, I don't think that this is possible as current physical theories do not explain everything known about the universe so if this guy can perfectly model the universe I would think that the physics community would look on him like a god. Just to show the complexities of QM theory (and this is a WELL UNDERSTOOD phenomenon not one of those as yet unexplainable ones), if you put a particle (let's call it an electron just so we can picture it) into a box and made the walls of the box such that it would take an infinate amount of energy to get the particle past that wall, with our a priori notions of matter, we would expect that the particle is doomed to stay in the box for all time. However, if we work out the wave equation for that particle and use that to calculate the probability densities over the spatial coordinates, we find that the particle has a finite probability of being outside of the box. This is not just theoretical. This is the basis of the principle of tunnelling on which all semiconductor technology is based. Maybe you can clarify what this "Deutch" was talking about and when he said it? -- David S. Angulo (312) 266-3134 Datalogics Internet: dsa@dlogics.com 441 W. Huron UUCP: ..!uunet!dlogics!dsa Chicago, Il. 60610 FAX: (312) 266-4473