Kepler rule #2 never sunk in for me; the other two rules seemed fairly intuitive. Kepler was Tycho Brahe's lab assistant, I think. Tycho was a curious chap. In

Kepler rule #2 never sunk in for me; the other two rules seemed fairly intuitive. Kepler was Tycho Brahe's lab assistant, I think. Tycho was a curious chap. In addition to his brass nose, I believe he also had a "person of restricted stature" as a servant; that doesn't seem to be mentioned in his wikipedia article.