Johannes Kepler

Johannes Kepler

Johannes Kepler (; German: [joˈhanəs ˈkɛplɐ, -nɛs -] (listen); 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of planetary motion, and his books Astronomia nova, Harmonice Mundi, and Epitome Astronomiae Copernicanae. These works also provided one of the foundations for Newton's theory of universal gravitation.Kepler was a mathematics teacher at a seminary school in Graz, where he became an associate of Prince Hans Ulrich von Eggenberg. Later he became an assistant to the astronomer Tycho Brahe in Prague, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. Read more on Wikipedia

Since 2007, the English Wikipedia page of Johannes Kepler has received more than 4,673,413 page views. His biography is available in 141 different languages on Wikipedia (up from 139 in 2019). Johannes Kepler is the 3rd most popular astronomer (up from 5th in 2019), the 11th most popular biography from Germany (up from 31st in 2019) and the most popular German Astronomer.

Johannes Kepler is most famous for his three laws of planetary motion. His first law states that the planets orbit the sun in ellipses, not circles. His second law states that a line connecting the planet to the sun sweeps out equal areas in equal times. His third law states that the square of the orbital period is proportional to the cube of the semi-major axis.