Kepler

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.