Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!uwvax!umn-d-ub!umn-cs!mmm!cipher From: cipher@mmm.UUCP (Andre Guirard) Newsgroups: sci.misc Subject: Re: Engines of Creation: Nanotechnology Message-ID: <1526@mmm.UUCP> Date: Mon, 30-Nov-87 11:33:27 EST Article-I.D.: mmm.1526 Posted: Mon Nov 30 11:33:27 1987 Date-Received: Thu, 3-Dec-87 07:20:26 EST References: <799@sbcs.sunysb.edu> <2698@drivax.UUCP> <1063@sugar.UUCP> <2411@watcgl.waterloo.edu> <1445@m-net.UUCP> Reply-To: cipher@mmm.UUCP (Andre Guirard) Organization: Software & Electronics Resource Center/3M Lines: 23 Keywords: nanotechnology foresight drexler In article <1445@m-net.UUCP> russ@m-net.UUCP (Russ Cage) writes: >In <2411@watcgl.waterloo.edu> kdmoen@watcgl.waterloo.edu (Doug Moen) writes: >>[...] If it *does* turn out to be possible to build Grey Goo, >>then by the time fabrication technology catches up, perhaps we can have >>a wide spectrum of Goo killing techniques already available. >You have to find it first. The difficulty is that, in order to decide >if a particular bit of nanomachinery is Gray Goo (or a part thereof), >you have to analyze its program to see if it ever quits reproducing. >This is exactly equivalent to the halting problem, which is insoluble. Fortunately solving the halting problem is not necessary to controlling Grey Goo. Better safe than sorry: we kill any nanomachinery that we can't prove will stop reproducing in a reasonable amount of time. After all, there is little practical difference between something that never stops reproducing and something that stops after 100 million years. -- o Andre Guirard < ' The race is not always to the swift... "Thai green beads" / > but it's a pretty safe bet. ihnp4!mmm!cipher '