Cheers,
Pierre J. Boulos
Department of Philosophy
The University of Western Ontario
University of Windsor
pboulos@julian.uwo.ca
boulos@uwindsor.ca
> -----Original Message-----
> From: James A Landau <JJJRLandau@aol.com>
> Sent: Sunday, March 21, 1999 5:57 PM
> To: historia-matematica@chasque.apc.org
> Subject: Re: [HM] Mathematical Physics
>
>
> At 12:34:27 EST on 99-03-20 jongsma@dordt.edu (Calvin Jongsma)
> wrote:
>
> > When did mathematical astronomy become thought of as an
> > instrumental theory (useful for prediction, but not a theory of
> > what really happens)?
> > Does this go back to Ptolemy? Earlier? Later?
> > And what about the other mixed mathematical sciences
> > (optics, mechanics, etc): were they also viewed in instrumental
> > terms, or was it only astronomy?
>
> In December 1998 as part of the thread
>
> Re: [HM] earliest writing discovered, contained numbers
>
> we had a discussion of how astronomy came to be. One of the few
> conclusions reached was that most agricultural societies need
> some form of calendars so that the farmers know when to plant
> their crops.
>
> For example, on 98-12-27 at 00:32:43 EST, Everdell@aol.com (Bill
> Everdell) said:
>
> > *Much* more serious problem for agriculturists, I think, is when
> > to put that seed in the ground early enough to give you food
> > before you run out of last year's store and end up eating that
> > seed, and late enough so the seed won't freeze. But calendar
> > math seems to be already around rudimentarily before writing. I
> > think it's astronomical calendar calculation that must have
> > given early farmers the greatest need for the most demanding
> > math.
>
> Hence quite a number of early societies invented astronomy for
> purely practical purposes, including
> - deciding when to plant
> - predicting eclipses (which are quite scary if they happen
> without warning)
> - astrology (whatever you may think of astrology, you have to
> admit that it is a practical application of astronomy)
> - timing of religious festivals
>
> If I understand your usage of "instrumental" correctly, then
> astronomy started out almost everywhere as an instrumental
> discipline, which in a few societies later went off into theory.
>
>
> The thread also contained an inconclusive discussion of whether
> early agriculturists needed math (e.g. geometry for surveying,
> arithmetic for computing quantities of seed grain). Does this
> also mean that early geometry and arithmetic meet your definition
> of "instrumental"?
>
>
> Back to your original question. I think you have things
> backwards, and astronomy started out everywhere as an
> instrumental field and only in a few places turned theoretical.
>
> **********************************************************
>
> Ptolemy actually came relatively late in the history of
> astronomy. Chinese astronomy goes back some four thousand years,
> maybe more. Ptolemy is closer in time to us than to the first
> Chinese astronomers.
>
> There is a theory, not necessarily correct but at least
> plausible, that Stonehenge was an astronomical observatory, or at
> least a piece of instrumentation for predicting eclipses.
>
> ***********************************************************
>
> Until 1802 astronomy was almost entirely astrometry, that is, the
> study of the positions and movements of the stars, Sun, Moon, and
> planets. (In 1802 Wollaston discovered the dark lines in the
> Sun's spectrum, and this work, and more importantly Fraunhofer's
> work on spectroscopy starting in 1814, created the field of
> astrophysics).
>
> I do not wish to claim that Ptolemy was/was not primarily a
> theorist interested in the how of the universe, but his work and
> that of other Greek, Alexandrian, and later theorists was still
> immensely practical. They provided not just theories but
> practical techniques for predicting the position of the Sun,
> Moon, planets, and stars far in advance.
>
> This was not easy. Think of how recent our current Gregorian
> calendar is! Astrology was important to the Medieval world (and
> to a lot of our contemporaries as well!) so the predictions of
> the positions of the planets was important. Also there was
> celestial navigation, and various religious purposes, such as the
> timing of Easter or for Muslims the direction in which to face to
> pray towards Mecca.
>
> I claim, I think without too much exaggeration, that until the
> invention of astrophysics by Wollaston and Fraunhofer, astronomy
> was primarily an applied rather than a pure science.
>
> Discussion, anyone?
>
> -- James A Landau
>