Johannes Kepler and His Scientific Contributions By Katelyn

Johannes Kepler and His Scientific Contributions By Katelyn Cooper

Apprenticeship • Lived from 1571 -1630 • German moved to Prague to become Brahe’s apprentice • Brahe told him to watch the orbit of Mars, so Brahe could continue with his theory on the solar system • He kept him occupied with the orbit of Mars because Brahe didn’t trust Kepler, he thought one day, Kepler would eclipse him as the premier astronomer of his time.

Kepler’s Theory • Kepler believed in the Copernican System, which placed the sun directly in the center of the planets orbits. • Kepler realized Aristotle was wrong when he said that the orbits of planets were circular. In the system Copernican assumed they were circular also. • Kepler proved that theory was not wrong but the shape of the orbit was, the orbits were flattened circles, also known as ellipses.

First Law of Planetary Motion • Kepler’s first law stated that the sun was not the center of planet’s orbits but at one focus. • Which means the sun’s distance is constantly changing.

Equal Area Law of Planetary Motion • The line joining the planet to the Sun sweeps out equal areas in equal times as the planet travels around the ellipse. • The planet moves faster when it is closer to the sun. • 2 parts: the perihelion and the aphelion

Harmonic Law of Planetary Motion • The ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semimajor axes. • Kepler's Third Law implies that the period for a planet to orbit the Sun increases rapidly with the radius of its orbit.

• P represents the planet’s period of revolution • R represents the planets axis’

Interactive Sites • Kepler's First Law • Simulation of Orbit

Bibliography • "Johannes Kepler: the Laws of Planetary Motion. " Johannes Kepler: the Laws of Planetary Motion. 15 May 2006 <http: //csep 10. phys. utk. edu/astr 161/lect/history/ kepler. html>. • Spaulding, Nancy E. Earth Science. Dallas: Mc. Dougal Littell, 1999. 405 -406. • Porter, Roy, and Marilyn Ogilvie. Dictionary of Scientists. 3 rd ed. Vol. 1. Great Brittain: Helican, 2000. 554 -557.