[sci.philosophy.tech] Mercury's day and other mysteries

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

weemba@garnet.berkeley.edu (Obnoxious Math Grad Student) (04/04/88)

In article <1149@3comvax.3Com.Com>, michaelm@vax (Michael McNeil) writes:
>So, if science really expects and thus *creates* whatever it discovers,
>how could it possibly be that Mercury rotates with respect to the sun?

Beats me.  I'd like to mention a more recent example of the same: this
past year Sky&Telescope reported that some high school students, as part
of a science project, found that a certain asteroid's period of rotation
was twice(?)/half(?) the rate previously assumed.

Let me recommend Pickering _Inventing Quarks_.  It's a beautifully writ-
ten history of HEP (high energy physics) from 1960-1980, stressing the
above philosophical point of view.  This is done partly to favor this
philosophical stance, but also as a counter to the standard scientist's
history, which tends to falsify so many things with the bias provided
by the successful theory.  This kind of false reconstruction is peda-
gogically useful, but it is philosophically very misleading.

ucbvax!garnet!weemba	Matthew P Wiener/Brahms Gang/Berkeley CA 94720

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