X-Message-Number: 12723 From: "John Clark" <> Subject: The Nanotech Fantasy Date: Fri, 5 Nov 1999 12:54:19 -0500 In #12710 On Thu, 4 Nov 1999 Charles Platt <> Wrote: >Industrial robots routinely assemble cars that are all basically the same >on a particular production line. Robots do not, and cannot, and will not >for the foreseeable future, repair car which are wrecked in many >different ways. I'll believe in brain repair by nanotechnology just as soon as >I see those car-repairing robots. I discussed this same topic with James Halperin when he was writing his book "The first Immortal" and I gave 6 reasons to support my view that a Nanotechnology repair line would be fundamentally easier (but still not easy!) than a macroscopic repair line: 1) The parts a macroscopic repair line uses would be very expensive, the parts that Nanotechnology uses, atoms, are very cheap. 2) A macroscopic repair line must use many thousands or millions of different types of parts and it must learn how to use all of them. At the most, Nanotechnology uses 92 different parts (the elements) but in the real world almost everything we know of is made of only about 20 parts, and for life about 10. 3) All the many different parts a macroscopic repair line uses are fragile, and fragile in different ways, the machine must learn the proper handling techniques for them all or it will destroy the parts before it can use them. There is no way you can damage the parts Nanotechnology deals with. 4) None of the parts in a macroscopic factory are absolutely identical. Despite our best efforts, individual variation still exists, and so we must deal with each part slightly differently and compensate for the variation in the assembly process if we want the finished product to work properly, that often takes intelligence. On the other hand, according to the laws of Physics one hydrogen atom is absolutely identical to another hydrogen atom and can be treated in exactly the same way. Atoms have no scratches on them to tell them apart. 5) Nanotechnology can manipulate matter without ever leaving the digital domain. You may have to deal with a rod 27 carbon atoms long, or 28 atoms long, but you never have to worry about a rod 27.5601334 atoms long. A Macro assembler wouldn't have that luxury when it tried to build a seat cover from a sheet of leather. 6) Most of the parts a macroscopic repair line uses would have to be very complex and the ways they interact with other macroscopic parts would be even more complex. Think of the windshield of a car, it interacts poorly with the engine block, and even with the windshield frame the interaction must be managed with great skill or you'll have a disaster. Nanotechnology is like building with Lego blocks, you can build structures of arbitrary complexity, yet there are only a few different types of blocks and they interact with other blocks in only a few different ways. It's easy to develop an algorithm to examine any Lego object and then build a duplicate, it's very far from easy to find an algorithm that would do the same with the complex parts in a car. John K Clark Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12723