michaelm@vax.3Com.Com (Michael McNeil) (04/02/88)
In article <8087@agate.BERKELEY.EDU> weemba@garnet.berkeley.edu (Obnoxious Math Grad Student) writes: >In article <26193@cca.CCA.COM>, g-rh@cca (Richard Harter) writes: >> Gee, when I saw the word Mercury, I thought you were going to mention >>the "fact" that Mercury is tidally locked to the Sun with the same side >>always facing the Sun -- a "fact" confirmed both by theory and careful >>observation. > >Ironically enough, the classical observations fit the correct rotation rate >better than they did the assumed one, but no one had ever checked. Mercury >is *very* difficult to observe. I'm quite fond of the case of Mercury's rotation, because I believe it's perhaps the clearest example in recent scientific history of a completely unexpected discovery, even by the discoverers. There's a current among some of the more Idealistically inclined, which holds that science never "discovers" anything -- instead it *creates* what it "discovers." E.g., atoms didn't exist until scientists started believing, and looking, for them -- whereupon they popped into "existence" via real wishful thinking. As far as I know, no one on Earth by the time of the 1960's expected Mercury to rotate at any rate other than 1:1 locked-in tidal motion. The examples of our Moon with the Earth, and the moons of Jupiter with it, were simply too strong, and no one seriously doubted that Mercury did likewise. The radio astronomers who discovered the real rotation of Mercury were looking for something else entirely -- but the evidence contained within the data they collected was too clear to be overlooked. So, if science really expects and thus *creates* whatever it discovers, how could it possibly be that Mercury rotates with respect to the sun? Michael McNeil 3Com Corporation Santa Clara, California {hplabs|fortune|idi|ihnp4|tolerant|allegra|glacier|olhqma} !oliveb!3comvax!michaelm All of these endeavors are based on the belief that existence should have a completely harmonious structure. Today we have less ground than ever before for allowing ourselves to be forced away from this wonderful belief. Albert Einstein, *Essays in Science*, 1934
merlyn@rose3.rosemount.com (Brian Westley) (04/06/88)
Mercury isn't totally unaffected by tidal locking. It's day:year ratio is 2:3. What's the mystery? Merlyn LeRoy