On this date, December 27, 1571, Johannes Kepler was born.

[WestMichRad]

1. Kepler conjecture and Rudolphine tables

Mention of these sent me (happily) down a couple of rabbit holes! FYI:

The Kepler conjecture was his proposition for the maximum density achievable for close packing of spheres. It resulted from a query by Sir William Raleigh about the best way to pack cannonballs. A mathematical proof of Kepler’s solution was only achieved by computer in 1997.

The Rudolphine tables were published data (from Tycho Brahe and his team) of positions and motion of the stars and planets. While Brahe believed in the geo-heliocentric model, in which all revolved about the earth, Kepler showed that the data in fact supported a heliocentric model, in which the planets orbit our Sun and that there is no universal center.

Given the state of knowledge at that time, Kepler was an absolutely brilliant mathematician!