No study of Astronomy is complete without Kepler ! Did he not bequeth the Laws of Planetary Motion to the world ?
Astronomy is nothing but Mathematical Astrology and Kepler gave the world the three laws of Motion.
1) The planets move in elliptical orbits.
20 Planets move fastest at perihelion ( nearest point to Helios, the Sun ) and slowest at Aphelion ( the farthest point from the Sun ).
3)The squares of their sidereal periods ( orbital periods ) is equal to the cubes of their semi major axes.
The base of Western Astronomy is Kepler. First we study Kepler and then we study Laplace !
Previousy astronomers ( Hipparchus, Ptolemy, Brahe, Copernicus ) have used many geomertical models to give a mathematical account of the movement of the luminaries. Astronomy is a branch of Physics, declared Kepler. In this great book, Kepler’s Physical Astronomy, Bruce Stephenson demonstrates the importance of Kepler’s physical principles of planetary motion. A must book for students of Astronomy and Mathematical Astrology. Also for the creation of Astronomy and Astrology softwares. In any type of Astro software, let it be Indian, Western or Chinese Astrology, or Yahoo Astrology, this book contains great info which is good for the developer.