In the rush to assign/deny credit for the sine law, one does well to
recall Robert K. Merton's dictum that in science, "it's not yours until
you give it away." Hariot and Snel may have come across the relationship,
though, as David Fowler seems to suggest, it's easier to find it in the
former's papers if you know what you're looking for. But neither man
divulged his finding to the rest of the learned world. Descartes did,
loudly and proudly, in the Dioptrique of 1637. More important, he showed
what one could do with the law: solve the anaclastic problem, analyze the
optics of vision and calculate corrective lenses, explain the rainbow and
calculate its position (or rather explain why it appears where it does),
and relate the behavior of light to that of bodies moving through media
of differing densities. In short, he put a new mathematical optics on
the agenda of the science of his day, and subsequent investigators took
it from there. I should think the emergence of a powerful new model of
nature and an effective means of analyzing it are of much greater historical
significance than "international scientific credit-assigning". If the
goal of the course is to convey how science works, or more precisely how
in the 17th century it first came to work the way it does now, what
Descartes did with the law of refraction is far more important than
whether Hariot or Snel had it first.
Mike Mahoney
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Michael S. Mahoney Department of History Princeton University
mike@princeton.edu 303 Dickinson Hall Princeton, NJ 08544
phone 609-258-4157 fax 609-258-5326
WWW Home Page http://www.princeton.edu/~mike
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----------------------------Original message----------------------------
Thanks colleagues, and especially Susana Mataix, for the historical
information about Snell's/Descartes's Law. Based on sources not easy for me
to locate in several languages, one of which I don't read, it will be very
useful in my general history course that is just about to hit the "scientific
revolution" and the 17th century as an example of the messiness of
international scientific credit-assigning.
-Bill Everdell, Brooklyn