From: utzoo!decvax!duke!bek Newsgroups: net.physics Title: long superconductors Article-I.D.: duke.2883 Posted: Sat Jan 8 16:29:21 1983 Received: Sun Jan 9 02:29:07 1983 about that long superconductor... The original article claimed that such a wire would need to be cooled only at one end by a refrigerator with sufficient power to remove all the heat absorbed along the length of the wire. I think the concept is basically viable. my comments on opposing articles (so far) Someone thought that a heater at one end (ie. the environment) could heat up the whole wire (via the same logic used to validate the single refrigerator theory.) But note that the cold end has a superconductor working for it while the hot end does not. Thus the argument which says you can heat the wire from one end just like you cool if from the other is flawed. Someone said that if we could effect free heat transfer we would already being so to solve our energy problems. Don't I remember a similar statement made years ago with respect to man, wings, and flying? Someone noted that real wires get epilepsy when subjected to extreme temperature gradients. (probably the most sensible comment made so far, including mine.) OK, so there are start-up problems with the wire. Barrett Koster duke!bek