4. Revolution of the Spheres

Joshua Barnes -- Fall 1999

Last: 3. Ancient Astronomy Next: 5. Formation of the Solar System

The `revolution' described in this week's lecture is a revolution in human thinking. Copernicus started the revolution by recognizing the Earth as one of several similar planets, but he still used laws of planetary motion different from the laws applicable to motion on Earth. Newton completed the revolution by showing that planetary motion and terrestrial motion obey exactly the same laws. Between these two are Kepler, who wrote down the first correct laws of planetary motion, and Galileo, who found observational evidence for the Copernican system and clarified the nature of motion on Earth.


Web Resources:

Further Reading:

Homework 4: Planetary Positions, due 9/20.

Quiz 4: Kepler's Laws

Joshua E. Barnes (barnes@ifa.hawaii.edu)
Last modified: September 17, 1999