Re: This Week's Finds in Mathematical Physics (Week 207)

From: Robert J. Kolker (robert_kolker_at_hotmail.com)
Date: 08/06/04 

Date: Fri, 06 Aug 2004 17:56:05 GMT

John Baez wrote:

>
> According to Ted Bunn, whom I trust, Copernicus moved on to
> epicycles. Indeed Kepler must have been trying something like
> this when anomalies in the orbit of Mars pushed him into trying
> ellipses.

Both Kopernik and Galileo were philosophically wedded to uniform
circular motion. They bought the Aristotlean package, which is ironic,
since many of Galileos works showed Aristotle to be incorrect. Galileo
also did not get inertial quite right. He believed in circular inertia.
It was Descartes who got what came to be known as Newton's First Law,
correct.

Kepler was different and lucky. First, he had Tycho's numbers, which
were the best ever produced by naked eye astronomy. Second, Kepler was a
neo-Platonist who believed that the Sun ruled the motions of the planets
in some weird and wonderful fashion (Kepler had not worked out the
concept of force in sufficient detail). Third, Kepler was a fanatic and
an ueber anal retentive who would not give up until he had things right.

Kepler also believed the Moon influenced the tides on Earth. Galileo
repremanded Kepler for believing in such arcane "moonshine". The idea
that a body a quarter of a million miles distant could influence tides
was disdained by Galileo as mystical hogwash.

Bob Kolker

Relevant Pages
Quantcast