Jake Bowersox, Grade 7
Johannes Kepler was a famous mathematician and astronomer who formulated the three laws of planetary motion. He thought of himself as a mathematician and a historian.
Kepler was born on 27 December 1571 in Germany. As a child Johannes was often sick. His hands were crippled and his eyesight was impaired after he contracted smallpox. His mother Katharina Guldenmann was a herbalist who helped her father manage an inn. Katharina was accused of practicing witchcraft and was imprisoned for fourteen months. Throughout her trial, Kepler was said to be by her side.
Kepler's father Heinrich died while was fighting as a mercenary in Holland when Johannes was only 5 years old.
Many noted that Johannes was especially gifted in mathematics from a young age. His mother inspired him by taking him out at night to show him interesting things in the heavens, including a comet and a lunar eclipse. He saw a comet when he was six and a lunar eclipse when he was nine. He remembered for his lifetime the experience of seeing the moon turn red (“blood moon”) during an eclipse.
Kepler was a man who thought of science and religion as working together. He was a pious Lutheran whose writings include theology. He said, “God is the beginning and end of scientific research and striving.”
"I wanted to become a theologian," he wrote. "For a long time I was restless. Now, however, behold how through my effort God is being celebrated in astronomy."
Kepler said, "We astronomers are priests of the highest God in regard to the book of nature."
He wanted to go into ministry and sought ordination after seminary, but instead he went to University of Tübingen where he studied Greek, Hebrew, geocentric astronomy, and mathematics. In his first year there Kepler received excellent grades for everything except mathematics.
Kepler taught math at a seminary school in Graz, Austria and was assistant to the court mathematician for Emperor Rudolph II. In 1600 he moved to Prague to research with Tycho Brahe. From Tycho's death in 1601 until the ouster of Emperor Rudolph II in 1612, Kepler was Europe's most respected mathematician.
Kepler married Barbara Muller in 1597. She was a widow with a young daughter. In the first year of their marriage, they had two daughters who died in infancy. Three more children followed, but Barbara’s health was failing and she died in 1612.
In 1613, Kepler married 24 year old Susanna Reuttinger. The first three children born from this marriage died in infancy.
Kepler's contribution to Science
He invented a better version of the refracting telescope. He used Tycho Brahe's Tables to prove the Laws of Planetary Motion.
Law of Ellipses
Kepler's first law - also known as the law of ellipses - says that planets orbit the sun in an oval path called an ellipse. The path the planets orbit the sun is an ellipse, with the the sun in the middle.
The Law of Equal Areas
Kepler's second law - also known as the law of equal areas - describes the speed at which any given planet will move while orbiting the sun. The speed at which any planet moves through space is constantly changing. A planet moves fastest when it is closest to the sun and slowest when it is furthest from the sun. An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time.
The Law of Harmonies
Kepler's third law - also known as the law of harmonies - compares the orbital period and radius of orbit of a planet to those of other planets. Unlike Kepler's first and second laws that describe the motion characteristics of a single planet, the third law makes a comparison between the motion characteristics of different planets. The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun.
Kepler died on 5 November 1630. He should be remembered and honored as a scientist through whose efforts God is celebrated in astronomy. He built on the work of two earlier Christians: Copernicus and Galileo.
Related reading: Kepler's Laws of Planetary Motion