History Lesson #105

  • Lesson 101: Johannes Kepler
  • Lesson 102: Galileo Galilei
  • Lesson 103: The Slide Rule
  • Lesson 104: John Napier

Johannes Kepler

Kepler is best known for his three planetary laws of motion. His first two laws are below:

  • The planets moved in elliptical orbits, as opposed to circular orbits.
  • The closer to the sun the planet is, the faster the speed.

Galileo Galilei

Galileo’s father wanted him to be a doctor. Galileo had accidentally gone into a lecture on geometry, and convinced his father to let him study math and philosophy. He observed a comet and a lunar eclipse, and that inspired him to do astronomy. He made his own version of the telescope once it came out.

The Slide Rule: invented by John Napier

John Napier saw a problem with the ability to do multiplication and division, so invented logs. Logs could be worked with by using the slide rule. John Napier would think about a problem and an invention that could help solve it. Unlike some people, he would make the invention, not just think about it.