OBJECTIVE:
Mathematically verify the validity of Kepler’s Third Law by analyzing the motion of Pluto’s moons.
MATERIALS:
- Access to the Internet
- Calculator
THEORY:
This activity will demonstrate the power and usefulness of
Johannes Kepler’s Third Law, sometimes called his Harmonic Law.
Kepler spent nineteen years of painful trial and error, looking for
something – anything – that all the planets had in common.
Each planet had the sun at one focus of its elliptical orbit, but that
was all. The motion, the speed, of each planet seemed unrelated
to the others, and that shook Kepler’s faith in God as the master
of geometry. When in 1619 he finally stumbled on the
mathematical connection in his Third Law, he found that longsought connection that linked all the planets together in some
mathematical way. And was he ever excited! See the quote from
Kepler in the box, at the left. In Kepler’s time, most people
believed that the earth was only a few thousand years old. If
Kepler were alive today he would say that God has waited for
billions of years!