Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site sunybcs.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!rocksvax!sunybcs!ugzannin From: ugzannin@sunybcs.UUCP (Adrian Zannin) Newsgroups: net.startrek Subject: Re: Re: New discussion Message-ID: <2487@sunybcs.UUCP> Date: Tue, 12-Nov-85 19:57:23 EST Article-I.D.: sunybcs.2487 Posted: Tue Nov 12 19:57:23 1985 Date-Received: Thu, 14-Nov-85 01:01:23 EST References: <353@uw-june.UUCP> <8500013@orstcs.UUCP> <198@ur-tut.UUCP> Distribution: net Organization: SUNY/Buffalo Computer Science Lines: 29 > In article <8500013@orstcs.UUCP> jamesp@orstcs.UUCP (jamesp) writes: > >This is called "Cherenkov Radiation," and happens all the time. Often a > >subatomic particle is moving faster than the speed of light in a medium (for > >example, the speed of light in water is much less than the speed of light in a > >vacuum -- ever seen a picture of a nuclear reactor with that beautiful > >sky-blue "radioactive" glow? That's caused by lots of alpha and beta > >particles ripping through the water faster than the speed of light.) > > WHAT??? The speed of light in water is much less than the speed of light > in a vacuum???? AAAUUUGHH!! Einstein just rolled over! I always thought: > 'The speed of light is the same for all observers, no matter what his > frame of reference'... If what you say is true, then all kinds of phenomena > would open up simply by exceeding this 'slower' speed in water... Eek! Well, that is true. The speed of light is the same for all observers, no matter what his frame of reference *provided that the light is travelling through the same medium for both observers*. The speed of light *does* change when it passes through different mediums. This is why the different wavelengths of light are split apart from each other as the light passes through a prism. (You are familiar with this concept, yes?) The last line of the first posting should have specified the speed of light with respect to which medium... -- Adrian Zannin ..{allegra,bbncca,decvax,dual,rocksvax,watmath,sbcs}!sunybcs!ugzannin CSNET: ugzannin@Buffalo.CSNET ARPANET: ugzannin%Buffalo@csnet-relay.ARPA BITNET: ugzannin@sunybcs.BITNET