Asri-unix.508 net.space utcsrgv!utzoo!decvax!ucbvax!menlo70!sri-unix!JGA@MIT-MC Thu Jan 14 10:27:46 1982 Question on Michelson-Morley experiment From: John G. Aspinall The Michelson-Morely experiment has been repeated many times. A summary of a number of these experiments appeared in a review article by Shankland et al. [1] in 1955. The best test I could find a reference to, is one using lasers in 1964 [2]. (I found pointers to both these references in "Special Relativity", by French.) In none of these experiments, was there any detected fringe shift that could be ascribed to ether motion. Later experiments put successively lower bounds on any possible motion. In the laser experiment, "... No change in beat frequency ... was detectable within the accuracy of the measurement (about +/- 3kHz). This was less than 1/1000 of the change that one would calculate from an ether-wind hypothesis...." (Quote from French.) Now fringe shift (or beat frequency shift - same thing) is proportional to the square of the velocity difference, so this means that any motion is down by a factor of more than 30 from the ether-wind hypothesis. This is certainly not the detected motion that Stine claims. I haven't read the Stine column, and I would be interested to hear if the letters section in following months had any complaints about this in it, but I will inject one personal note here. This is the sort of thing that gives SF a very bad name - if we (the collective SF community, editors especially) let this sort of thing go unchallenged, then we deserve the reputation of not being able to distinguish fact from fiction. SF might as well be all fantasy. Any claims to being intelligent speculation about "what might happen" go out the window, in the eyes of many. Agreed, there is a line to be drawn between stifling creative thought, and "print everything as fact", but you don't overcome "math anxiety" by telling the student that all answers are right. Likewise you don't encourage intelligent speculation about OUR world, by ignoring what we know already. [1] Shankland et al., Rev. Mod. Phys., 27, 167, (1955). [2] Jaseja et al., Phys. Rev. 133, A1221, (1964). John Aspinall. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.