Johannes Kepler was a German scientist who dedicated his life trying to understand the movement of celestial bodies. He is most famous for his three laws of planetary motion.
Johannes Kepler was a German scientist and mathematician. He was born on December 27, 1571 in Weil der Stadt, Germany. He won a scholarship to study religion at the University of Tübingen. While there, he studied the work of Nicolaus Copernicus and his ideas about a heliocentric system. Although there was no evidence to support the Copernican theory, Kepler publicly defended it. This was a dangerous position to take at the time as the Lutheran and Catholic churches were both against the theory.
Kepler is most famous for his work on planetary motion. Kepler assisted the Danish Scientist Tycho Brahe make observations of the solar system. Through these observations, he described the orbits of the planets in our solar system. He paid particular attention the the retrograde motion of Mars; Mars appeared to move backwards in the night sky. Brahe wouldn’t share all of his data with Kepler, restricting what Kepler could see. It wasn’t until Brahe died in 1601 that Kepler had full access to all of Brahe’s observations. From this detailed data, Kepler formulated his theory of planetary motion.
Kepler's theory stated three laws: Law of Orbits, Law of Area, and Law of Periods (or Law of Harmonies). The first states planets move around the sun in ellipses, which look like flattened circles or ovals. Before this, scientists had explained the apparent motion of the planets using epi-cycles, which are circles within circles. His second law states that the closer a planet is to the Sun in its orbit, the faster it will move (in proportion with its distance to the Sun). The third law relates the movement of the different planets. A planet which is far away from the Sun will have a longer revolution than a planet that is closer to the Sun, but the ratio of the squared period and cubed average distance remains the same.
(Revolution Period)2 / (Avg. Distance to Sun)3 is the same for each planet.
Kepler also studied a supernova, now known as Kepler’s Supernova, which appeared in 1604. He observed and made detailed notes for a year.
Kepler died on November 15, 1630 at age 58 in Regensburg, Bavaria.
“Truth is the daughter of time, and I feel no shame in being her midwife.”
“Nature uses as little as possible of anything.”