Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site lasspvax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!mhuxn!houxm!vax135!cornell!lasspvax!cpf From: cpf@lasspvax.UUCP (Courtenay Footman) Newsgroups: net.physics Subject: Re: Re: Question on FTL and quantum mechanics Message-ID: <146@lasspvax.UUCP> Date: Wed, 5-Dec-84 15:56:16 EST Article-I.D.: lasspvax.146 Posted: Wed Dec 5 15:56:16 1984 Date-Received: Fri, 7-Dec-84 01:39:16 EST References: <654@ames.UUCP> <6201@mcvax.UUCP> <274@mhuxm.UUCP> <> Reply-To: cpf@lasspvax.UUCP (Courtenay Footman) Distribution: net Organization: Theory Center (Cornell University) Lines: 37 Summary: In article <> gjk@talcott.UUCP (Greg J Kuperberg) writes: >> You ought to read up on tachyons which are particles moving faster >> than light. They can't slow down in the same way that we can't speed >> up to c. There is no known evidence of tachyons. > >Tachyons are dead. Some respected physicist published a paper on them >once. There were many replies, to the effect of, "you made a mistake in >your physics." The guy then said, "oops", and that was the end of it. Tachyons are not dead. In the latest Physics and Astronomy Clasification System, (PRL 26 Nov), classification 14.80.Pb exists, with the following definition: The Physics of Elementary Particles and Fields (the 1) Properties of specific particles and resonances (the 4) Others and hypothetical (the 80) Others (including tachyons) (the P; the b is a check sum) The last 4 Physics Abstracts (~two months worth) describe three papers with the word tachyons in the title. This is not a very active field, but neither is it "dead". It is true that most practicing physicists (including me) do not believe in tachyons and that tachyons seem to have serious diseases, most notably with causality. Also no evidence for tachyons has yet been found, and there is strong evidence that charged tachyons with a "mass" less than a few times the electron mass do not exist. (If they did, they would strongly affect the rate of light by light scattering; since QED correctly predicts this rate with the electron being the only light charged particle, other light charged particles, including tachyons, do not exist). However, some people are still doing research on the subject, and while I think most of them would also agree that tachyons probably don't exist, they would insist on the "probably". -- Courtenay Footman arpa: cpf@lnsvax Newman Lab. of Nuclear Studies usenet: cornell!lnsvax!cpf Cornell University