Johannes Kepler Biography

William Martin

Mr. Percival

Astronomy Pd. 1

October 15^th, 2010

Johannes Kepler Biography

Johannes Kepler was born in 1571 in a town called Weil in Wurmberg, now located in Southwestern Germany.  In his early life, Kepler was very interested in religion and received a degree in theology, later entering the University of Tubingen, at the time renowned for its Protestant teachings, where he graduated in 1591. At this school, Kepler became very advanced in mathematics, and went on to take a teaching position at a small school in Austria. However, his small numbers of students gave Johannes much free time to pursue his newfound interest, astronomy.

A dedicated believer in Copernicus’s heliocentric theory, Kepler tested many of Copernicus’s observations for accuracy and accounted any errors and discrepancies to miscalculations or observations but was unwilling to move away from Copernicus’s theory. In 1600, an astronomer by the name of Tycho Brahe noted Kepler for his skills in mathematics and invited him to Prague to use Brahe’s observations to calculate the distances of the planets.  Brahe was known for taking some of the most consistent and detailed observations on record, and thus when he passed away shortly after in 1601 he left much for Kepler to work with and analyze. 

In 1610, Kepler got word of Galileo’s recent invention of the telescope and made a version for his own personal use shortly after. With this, he confirmed Galileo’s assertion of Jupiter’s planets and verified many other observations, taking some of his own along the way.

  Using his observations, Kepler finally strayed from the common beliefs of Aristotle and Copernicus and came to the conclusion that planets orbit in ellipses rather than circles. After recalculating the distances of the planets using Brahe’s observations, the numbers seemed to fit and Kepler had made one of the most important discoveries in astronomical history.

Using his newly found discovery, Kepler was able to establish three main laws, widely known as the laws of planetary motion. The first law states that the orbits of the planets are ellipses, with the sun as one focus of the ellipse.  The second law explains that the line joining the planet to the sun sweeps out equal areas in equal times as the planet travels around the ellipse. Kepler’s final law stated that the ratios of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes in the semi major axes, or better known P^2 = R^3.

           Although he died in 1630, because of his great contributions to the field of astronomy, Kepler is still regarded as one of the most important astronomers and mathematicians to ever live.  The impacts he made still form the backbone of astronomy and are used on a regular basis.