Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site heurikon.UUCP Path: utzoo!watmath!clyde!floyd!harpo!seismo!uwvax!heurikon!jeff From: jeff@heurikon.UUCP Newsgroups: net.physics Subject: Atomic clocks - Who knows if they're correct? Message-ID: <229@heurikon.UUCP> Date: Thu, 16-Feb-84 01:53:14 EST Article-I.D.: heurikon.229 Posted: Thu Feb 16 01:53:14 1984 Date-Received: Sat, 18-Feb-84 03:21:19 EST Organization: Heurikon Corp., Madison WI Lines: 27 Einstein's Universe was on TV (again) last week. I pick up a little bit more each time I watch it. But, I have a question about atomic clocks and what the heck the correct "time" means: What if the NBS atomic clock went out? A power failure perhaps, or a critical component goes berserk. They have a backup clock, you say? Okay, make it a catastrophic event like an earthquake. Anyway, *ALL* the NBS clocks stop. (Also, assume that our sister atomic clocks in Europe also go on the fritz or were down for maintenance. Let Murphy loose: "Previously unneeded backup systems will all fail at the same instant the primary unit looses power.") How would they reset the NBS clock? And how would anyone know if it was set correctly? What would be used as a standard? And what problems would develop it it were wrong, anyway? I know it's important to have syncronization between various places or events, but what's so important about knowing what time it is in *absolute* terms? Post responses, please. Thanks. -- /"""\ Jeffrey Mattox, Heurikon Corp, Madison, WI |O.O| {harpo, hao, philabs}!seismo!uwvax!heurikon!jeff (news & mail) \_=_/ ihnp4!heurikon!jeff (mail - fast)