What's New:

January 5, 2007

There now exists yet another almost-elliptical animation, this time in Chapter 30, where Kepler develops his table of Sun-Earth distances.

December 17, 2006

Based on an idea from Michelle, Chapter 21 now has its own page with animations. Now the real false hypothesis is available, rather than only an algebraic attempt to make a catenary.

December 7, 2006

Chapter 9 is now complete, with more animations, and with corrections.