in the small town of Weil der Stadt in Swabia and moved to
nearby Leonberg with his parents in 1576, Kepler is now chiefly remembered for discovering the three laws of planetary motion that bear his name published in 1609 and 1619. As much of his correspondence survived, we know a significant amount of Keplerís life and character. He did important work in optics, discovered two new regular polyhedra, gave the first mathematical treatment of close packing of equal spheres which led to an explanation of the shape of the cells of a honeycomb, gave the first proof of how logarithms worked and devised a method of finding the volumes of solids of revolution that can be seen as contributing to the development of calculus. Moreover, he calculated the most exact astronomical tables then known, whose continued accuracy did much to establish the truth of heliocentric astronomy.