Johannes Kepler's Accomplishments

Johannes Kepler was born December 27, 1571. He was a German mathematician, astronomer, astrologer, and a key figure in the seventeenth century. He is best known for his eponymous laws of planetary motion. He believed that God had created the world according to an intelligible plan that through the natural light of reason. Kepler's first major astronomical work, Mysterium Cosmographicum, was the first published defense of the Copernican system. On July nineteenth 1595 he had an epiphany. He realized that regular polygons bound one inscribed and one circumscribed circle at definite ratios, which, he reasoned, might be the geometrical basis of the universe. After this hypothesis failed he began to look into three-dimensional polyhedral. He realized
Mysterium was published late in 1596, and Kepler received his copies and began sending them to prominent astronomers and patrons early in 1597; it was not widely read, but it established Kepler's reputation as a highly skilled astronomer. The effusive dedication, to powerful patrons as well as to the men who controlled his position in Graz, also provided a crucial doorway into the patronage system. Though the details would be modified in light of his later work, Kepler never relinquished the Platonist polyhedral-spherist cosmology of Mysterium Cosmographicum. His subsequent main astronomical works were in some sense only further developments of it, concerned with finding more precise inner and outer dimensions for the spheres by calculating the eccentricities of the planetary orbits within it. In 1621 Kepler published an expanded second edition of Mysterium, half as long again as the first, detailing in footnotes the corrections and improvements he had achieved in the 25 years since its first