books.google.com.au - From Hipparchus and Ptolemy in the ancient world, through Copernicus and Brahe in the sixteenth century, astronomers had used geometrical models to give a kinematic account of the movements of the sun, moon, and planets. Johannes Kepler revolutionized this most ancient of sciences by being the first...http://books.google.com.au/books/about/Kepler_s_Physical_Astronomy.html?id=pxCYAeOqJg8C&utm_source=gb-gplus-shareKepler's Physical Astronomy
