Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!tektronix!hplabs!sri-unix!mikes@AMES-NAS.ARPA From: mikes@AMES-NAS.ARPA Newsgroups: net.physics Subject: none Message-ID: <317@sri-arpa.ARPA> Date: Tue, 25-Jun-85 21:22:57 EDT Article-I.D.: sri-arpa.317 Posted: Tue Jun 25 21:22:57 1985 Date-Received: Tue, 2-Jul-85 06:12:50 EDT Lines: 58 From: mikes@AMES-NAS.ARPA (Peter Mikes) et In reference to the topic raised by: Sender: "John A. McNelly.OsbuSouth"@Xerox.ARPA Subject: Re: Things that move faster than the speed of light To: physics@sri-unix.ARPA In-Reply-To: physics-request%SRI-UNIX:ARPA's message of 22 Jun 85 Message-Id: <850625-101837-1146@Xerox> >I just read "In Search Of Schrodinger's Cat," a book by John Gribbin, >intended to introduce laymen to the subject of quantum mechanics. Does >anybody have any comments on the following excerpt, with respect to >info. travelling faster than the speed of light? The first (long) >paragraph gives technical details on how the experiment works, the >second (short) paragraph gives the results of the experiment: that >information was transmitted instantaneously, faster than the speed >of light. [pp. 231-232] >>"The Sussex team, headed by Terry Clark, has tacked the problem of >>making measurements of quantum reality the other way around. Instead of The device being described looks like SQID = Superconductive Quantum Interference Device - however the topic you have introduced - namely the superluminal communication by means of quantum transition across macrosco- pic distances is more general - quite controversial, related to EPR and probably closely related to the 'future of QM'. I will give two references - both fairly accessible but more exact and technical than a popular book: 1) A.J.Legget: Schrodinger's cat and her Laboratory cousins. Contemporary Physics. Vol 25, No6, Nov/Dec 1984 pp583..598. ( The journal, by the way is a very readable review journal ppubli- shed in Europe - more oriented to application thNEn Rev.Mod.Phys.) 2)H.P.Stapp: Bell's theorem and the foundation of Quantum Mechanics. Am.J.Phys . April 1985. ( I do not have the pages on the preprint). Important fact about both is (and a ton of other papers over last 50 years) is that SLC ( SuperLuminalCommunication ) was not demonstrated in the labo- ratory - even though many ingenious experiments were proposed ( and at least on such tele-super-communicator is patented ) Some belive that it never will be demonstrated and the reason is that it is not clear what is collapsing when vawe function is measured ( a special case of the Quantum transition) : A quote from paper 2) above : According to Heisenberg, the probability function .. :"represents mixture of two things, partly a fact and partly our knowledge of a faCT: ...' It is in this aspect - interpretation of 'psi' where the foundations come in and make the whole issue very interesting.: