🚀 go-pugleaf

In article <51010@sun.uucp> livesey@sun.uucp (Jon Livesey) writes:
>
> [discussion of gnomons, Babylonian observations deleted]
>
>	As well as eclipses, the Babylonians collected observations of
>Venus accurate enough to allow dating of earlier records back to
>around 2000bc.  The Babylonians themselves might not have been able to
>carry out this dating over very long periods since they had no very
>good model of the movement of astronomical bodies, yet astronomical
>prediction is always an attractive goal, and the next few hundred
>years of astronomy saw the development of such models, mainly by the
>Greeks, the Arabs, and finally Western Europe.
>
>  [more discussion of later history deleted]
>

There are, also, surviving records of tabulations of positions of the
other naked-eye visible planets.  We (the students in a class I took
on Babylonian and Greek astronomy) translated a cuneiform tablet which
contained the postions of the first stationary points of Jupiter over
several hundred years.  The tablet was written near the middle of the
period it covered, and thus contained both observational data and
calculted predictions, as well as some text that explained the
calculation method.  (The professor supplied the translation for the
text, as none of us read ancient Babylonian, except for numbers and
zodiacal signs.)

The positions were given in terms of degrees and minutes of arc around
the zodiac.  This zodiac was divided into twelve signs that
corresponded pretty closely to their current divisions (I think).  I
can't remember the date of the table off the top of my head, but I can
look it up if anyone's interested.

One of the points stressed in the course was that as far as we know,
the Babylonians didn't make any attempts to model the movements of the
stars or planets *physically*, just mathematically, along the lines of
"if it (the planet) is at this point in the sky now, where will it be
tomorrow or a hundred years from now?".  The Greeks, on the other
hand, spent most of their time trying to figure out what physical
system would account for the observed phenomema, and came up with all
sorts of amazing Earth-centered systems.

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