Johannes Kepler and Planetary Motion


Thales and Pythagoras suggested that the natural world could be understood. Aristotle dared to imagine what was beyond the Earth. Plato encouraged thought about the universe, even if he did take astronomy one step forward and two steps backward.

Copernicus followed in Ptolemy’s wake, devising the revolutionary heliocentric (sun-centric) model of the universe. Tycho Brahe may have (incorrectly) rejected that model, but he did make some of the most detailed night sky observations yet.

What’s more, by Johannes Kepler’s time, Tycho had cast doubt on the idea of uniform circular motion that had plagued astronomy for centuries.

At last, the world was ready for a more mathematical take on a question that had confounded philosophers, mathematicians, and classical astronomers alike: how do the planets truly move through space?

By standing on the shoulders of giants, Johannes Kepler was finally able to devise his three laws of planetary motion, which are still the leading mathematical theory today. Continue reading