Re: A rotating Earth?

[Digby Willard <dwillard@MAIL.CENTRAL.STPAUL.K12.MN.US>]

> It is interested that the volume by Copernicus had two parts.  The first
> in which Copernicus showed that choosing to have the earth move lead to
> great simplications in the sorts of models one had to build...indeed
> each planet no longer had to have the major epicycle...interest clue
> no?  But the second and longer part of the book where he tried in detail
> to make the model work failed miserably, yielding a result no less
> complicated that Ptolemy's.  Given that Copernicus was a neoplatonist
> who believed in the simple perfection of the heavens, to him his book
> must have been a failure.  I suggest to my students that Copernicus, the
> person we wrongly identify as first suggesting the earth went around the
> sun was for all intents and purposes a reactionary failure.


My understanding (still not from Kuhn...I don't have one) was that
Copernicus developed his model primarily because he was offended by
Ptolemy's departures from uniform circular motion.  That jibes with him
being a neoplatonist, assuming that a neoplatonist is one who expects the
universe to be perfect in a geometric way.  Ptolemy's model had everything
moving in circles, but not everything moved uniformly.  In the Copernican
model, everything went uniformly on circles.  As with Ptolemy's model,
there were circles moving on circles moving on circles.  So Copernicus'
model wasn't simpler, but it was more likely to satisfy his neoplatonic
demand for geometric perfection.

Also understood that Copernicus did not publish until he was close to
death, and that historians were not certain he lived long enough to see a
published copy of his work.  He was a priest, and I had thought that he had
been afraid of the consequences of publication.  But maybe he wasn't
satisfied with the results of his work, and only published when he realized
he wasn't going to get anything better?

I await comment, correction, clarification.

Digby