Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!rutgers!sri-spam!sri-unix!hplabs!pyramid!ctnews!gypsy!andrew!KFL@MX.LCS.MIT.EDU From: KFL@MX.LCS.MIT.EDU Newsgroups: sci.physics Subject: Speed of light Message-ID: <241@sri-arpa.ARPA> Date: Thu, 6-Nov-86 23:57:34 EST Article-I.D.: sri-arpa.241 Posted: Thu Nov 6 23:57:34 1986 Date-Received: Sat, 8-Nov-86 05:34:30 EST Lines: 35 From: "Keith F. Lynch" From: "James J. Lippard" ... When asked to explain how we can see stars millions of light years away if the universe is very young, [a creationist] ... indicated that the speed of light is decreasing. In ... 1934 ... Frank R. Edmondson ... said that by 1941, conditions would have changed enough that it would be possible to determine [whether the speed of light is decreasing] ... Can anybody tell me what was finally determined? For the past ten years it has been possible to measure the speed of light to 9 place precision. During that period no change has been measured. One might argue that it only recently stopped slowing down I suppose. A more common creationist answer to the question is that the light was created in transit, complete with information about nonexistant supernova explosions, fictitious recessional velocities, spectral spectral lines, etc. Another common answer is that we are mistaken about the scale of the universe and everything we see is within 6000 light years or so. A less common answer is that scientists have good evidence for creationism (including a small universe) and are deliberately deceiving the rest of us to promote irreligion or secular humanism or free love or whatever. Since 1982 the length of the meter (and hence of the inch, mile, etc) has been defined in terms of the length of the second and the speed of light. This means that the speed of light is now constant by definition. This also means that since 1982, nobody has measured the speed of light. Anyone who thought he was doing so was actually measuring the length of the meter! ...Keith