Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!umix!umich!itivax!m-net!russ From: russ@m-net.UUCP (Russ Cage) Newsgroups: sci.misc Subject: Re: Engines of Creation: Nanotechnology Message-ID: <1445@m-net.UUCP> Date: Thu, 26-Nov-87 10:12:02 EST Article-I.D.: m-net.1445 Posted: Thu Nov 26 10:12:02 1987 Date-Received: Mon, 30-Nov-87 03:34:40 EST References: <799@sbcs.sunysb.edu> <2698@drivax.UUCP> <1063@sugar.UUCP> <2411@watcgl.waterloo.edu> Reply-To: russ@m-net.UUCP (Russ Cage) Organization: M-NET, Ann Arbor, MI Lines: 16 Keywords: nanotechnology foresight drexler Summary: Stopping Gray Goo is like solving the halting problem. In <2411@watcgl.waterloo.edu> kdmoen@watcgl.waterloo.edu (Doug Moen) writes: >peter@sugar.UUCP (Peter da Silva) writes: >>Even Drexler is uneasy about the "Grey Goo". >[...] 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. -- The above are the official opinions and figures of Robust Software, Inc. Will you come quietly, or must I use earplugs? Russ Cage, Robust Software Inc. (313) 662-4147 {sw1a7,umix}!m-net!rsi