Posted by Pat on October 20, 1999 at 22:03:29:
In Reply to: Sagan the historian posted by Tom on October 20, 1999 at 16:54:34:
Tom:
Sagan's treatment of Kepler and other 17th-century scientists
: can be found in Chapter III.
Pat: As you can see, Sagan did nothing to hide Kepler's Platonic and Aristotlian roots. The story is only made more vivid by Sagan's contrast of the conflict and resolution in Kepler as he slowly let go of the old and accepted modern science.
I have the book before me. Here's p57 from Chapter III:
"There were only six planets known in Kepler's time: Mercury, Venus, Earth, Mars, Jupiter and Saturn. Kepler wondered why only six? Why not twenty or a hundred? Why did they have the spacing between their orbits that Copernicus deduced? No one had ever asked such questions before. There were known to be five regular or "Platonic" solids, whose sides were regular polygons, as known to the ancient Greek mathemeticians after the time of Pythagoras. Kepler thought that the two numbers were connected, that the reason there were only six planets was because there were only five regular solids, and that these solids, inscribed or nested one within another, would specify the distances of these planets from the Sun. In these perfect forms, he believed he had recognized the invisible supporting structures for the spheres of the six planets. He called his revelation The Cosmic Mystery. The connection between the solids of Pythagoras and the dispostion of the planets could admit but one explaination: the Hand of God, Geometer."