Meet Johannes Kepler: Eight Minutes of Arc

The war with Mars

Kepler inherited Tycho Brahe's peerless observations and tried for years to fit Mars into the perfect circles every astronomer since antiquity assumed. The best fit missed by eight minutes of arc — a sliver. Most would have shrugged. Kepler declared those eight minutes the road to reforming all astronomy.

The ellipse

Killing his beloved circles gave him the ellipse, three laws of planetary motion, and the foundation Newton built gravity upon. He did it while casting horoscopes to eat and defending his mother in a witch trial. Devotion to data over beauty, under conditions nobody would envy.

Why they belong at your table

Seat him for the courage to let evidence break your favorite idea. He'll ask what your eight arcminutes are — the discrepancy you keep ignoring.