Escape from Orbit
You may of heard how Galileo got into trouble for claiming that the Earth orbits the Sun. Did you know there were others that were saying the same thing? In the 16th century, Johannes Kepler was one of these. He was an astronomer who took measurements of the stars, but also an astrologer, producing horoscopes for the rich and powerful. Back then, the lines between science and mysticism were blurred and Isaac Newton himself was as much an alchemist as a scientist. Kepler took measurements of the movements of the planets, checking the measurements of other natural philosophers*. You can easily see planets with the naked eye, binoculars, or telescopes. They look like bright stars, but they move from night-to-night, giving them their name 'planetai' or 'wanderer'. Back in the 16th century six planets had been discovered. Kepler's idea of how they moved in their orbits was mixed with some ideas that we may find strange today. He combined his measurements with ideas th...