Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!rochester!pt.cs.cmu.edu!sei!sei.cmu.edu!firth From: firth@sei.cmu.edu (Robert Firth) Newsgroups: comp.ai Subject: Re: The Ignorant assumption Message-ID: <7059@aw.sei.cmu.edu> Date: 19 Sep 88 22:05:30 GMT References: <1369@garth.UUCP> <2346@uhccux.uhcc.hawaii.edu> <1383@garth.UUCP> <372@quintus.UUCP> <1390@garth.UUCP> <388@quintus.UUCP> Sender: netnews@sei.cmu.edu Reply-To: firth@bd.sei.cmu.edu (Robert Firth) Organization: Carnegie-Mellon University, SEI, Pgh, Pa Lines: 9 In article <388@quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes: >But is there any reason to suppose that the universe _is_ a Turing machine? None whatever. The conjecture is almost instantly disprovable: no Turing machine can output a true random number, but a physical system can. Since a function is surely "computable" if a physical system can be constructed that computes it, the existence of true random-number generators directly disproves the Church-Turing conjecture.