Johannes Kepler (1571-1630)

1. Johannes Kepler (1571-1630) • “Since we astronomers are priests of the highest God in regard to the book of nature, it befits us to be thoughtful, not of the glory of our minds, but rather, above all else, of the glory of God.”

2. Fast facts • Kepler was born and raised in Germany. • He went to college at the University of Tübingen. • He intended to become an ordained minister, but he had no money to support himself through school so he worked in the field of mathematics.

3. Fast facts • He taught math at the University of Graz in Austria. • He left due to religious persecution and went to Prague. • Johannes became an astronomer named Tycho Brahe’s assitant.

4. Accomplishments • After Tycho Brahe’s death, Kepler finished his planetary tables. Kepler was able to prove the heliocentric theory right and Tycho Brahe wrong. • Kepler also came up with the three laws of planetary motion. • He wrote a book called, “The Cosmographic Mystery,” along with many hymns, poems, and the first science fiction novel entitled, “The Dream.”

5. Accomplishments • Kepler invented an influential pre-calculus and a variation of the logarithm. • He examined the applications of math in optics and he also studied the telescope in great detail.

6. Three Laws of Planetary Motion • First Law: The orbit of a planet traces out the path of an ellipse with the sun at one of its two foci.

7. Three Laws of Planetary Motion • Second Law: A planet changes its speed according to its distance from the sun and the line joining the planet to the sun sweeps out equal areas in equal times.

8. Three Laws of Planetary Motion • Third Law: The squares of the periods of the planets are proportional to the cubes of their semimajor axes: Ta2 / Tb2 = Ra3 / Rb3 • The first cosmological model (see right)

9. Personal Life • Kepler had 5 children, 3 of which died during infancy, with his first wife, named Barbara Müller. They did not have a good relationship. • With his second wife, an orphan named Susanna Reuttinger, he had 7 children, 2 of which survived to adulthood. • Kepler died of a severe cold, possibly pneumonia, after going on a trip to seek the $50,000 dollars that the state owed him. They still owed it to him when he died.

10. What does he believe? • Kepler was an extremely strong Christian who grew up in the Lutheran church. He was one of the first people to believe in and prove the existence of a young earth. • He was very passionate about both God and science. One biographer sums it up like this, “It penetrates his entire creativity… it is this feeling for religion which above all lends [us] the special warmth which we experience with such pleasure when reading [Kepler’s theological and scientific studies]…at every opportunity the name of God crosses his lips.”

11. What does he believe? • Unlike many other astronomers, Kepler did not believe in such mystical things as horoscopes. He was, however, forced to write them in order to save himself from starvation. • The same biographer states that Kepler’s view of man’s chief purpose in life is as follows, “As the bird is created to sing, so, according to his convictions, is man created for his pleasure both in contemplating the magnificence of nature and in inquiring into her secrets, not for the purpose of extracting practical uses but to arrive at a deeper knowledge of the creator.”

12. The End! Created by Cara Dobrovodsky