Video: Astronomy: The Unbelievable European Genius of Kepler 400 Years ago – Kepler’s Third Law of Motion – Law of Periods (Astronomy)

[Just look at what this White man figured out using an ink pen as his only writing tool. I didn't even know about the 3rd law. You can weigh planets and moons using this formula from 400 years ago. Jan]

Here’s the video: https://www.youtube.com/watch?v=KbXVpdlmYZo