Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site hou2g.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!houxm!hou2g!stekas From: stekas@hou2g.UUCP (J.STEKAS) Newsgroups: net.physics Subject: Re: Atomic clocks - Who knows if they're correct? Message-ID: <175@hou2g.UUCP> Date: Mon, 20-Feb-84 18:11:26 EST Article-I.D.: hou2g.175 Posted: Mon Feb 20 18:11:26 1984 Date-Received: Tue, 21-Feb-84 08:01:46 EST References: <229@heurikon.UUCP>, <163@ihopa.UUCP> Organization: Bell Labs, Holmdel NJ Lines: 19 Since there is no such thing as absolute time, no clock can be constructed which is correct in an absolute sense. To wonder when an atomic clock will get out of synch with the sun is missing the point. The atomic clock has replaced astronomical standards because the physical processes which govern the atomic clock are better understood and can be better controlled. Atomic clocks also have a great advantage in that they are transportable. Dirac has suggested that the ratio of the gravitational force to the electromagnetic force is changing with time. That means that if astro- nomical standards of length and time are used, elecromagnetic forces would be increasing with time. If atomic (E&M) standards are used, then gravity would be weakening. Lunar laser ranging experiments were done to measure the effect, and the last I heard the evidence favored Dirac. Jim decreasing with respect to the electromagnetic force. When atomic and astronomical clocks disagree,