Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: cphoenix@csli.stanford.edu (Chris Phoenix) Newsgroups: sci.nanotech Subject: Re: Is this stuff for real? Keywords: reality nanotech questions Message-ID: Date: 3 Mar 91 04:03:46 GMT Sender: nanotech@athos.rutgers.edu Organization: Center for the Study of Language and Information, Stanford U. Lines: 28 Approved: nanotech@aramis.rutgers.edu Josh writes: > The inefficiencies in cells > are the very thing that allow mutation, and for lifeforms, that's > good. But you couldn't build a nanobot to mutate unless you tried > very very hard to achieve that specific goal. From what I've heard, it is true that a nanomachine can be easily designed to avoid mutation. But I don't believe it would be that hard to build one that mutated. All you'd need is some encoding of the specification in a format such that a high (say, .01%) number of random changes to the spec produced something meaningful. Then program it to change 3 bits of the spec before it replicates itself. "genetic" algorithms work in finding good solutions to problems, and while I don't know much about them, it seems that there should be a way to code a machine spec so that it could be optimized in this way. I can't see why anyone would want to, though. Seems like once we get nanocomputers it would be easier to do a top-down design and simulation, and get a machine that does exactly what we want (we hope) rather than relying on chance. [Genetic algorithms are a good example of what I'm talking about. As an experiment, try writing a self-reproducing program in C that introduces random changes in itself, and still works. Genetic algorithms use highly inefficient production system mechanisms for the same reason cells do--because they are the only way (we know of) to make evolution actually work. --JoSH]