Template:Are You Sure/January 15

Diagram of a Kovalevskaya top, a symmetric top in which two moments of inertia are equal, the third is half as large, and the center of gravity is located in the plane perpendicular to the symmetry axis (parallel to the plane of the two equal points).

• ... that Johannes Schöner was pioneer in the history of globe making, and that he played a significant role in the events that led up to the publishing of Copernicus' De revolutionibus in Nürnberg in 1543? • ... that a Kovalevskaya top is a symmetric top in which two moments of inertia are equal, the third is half as large, and the center of gravity is located in the plane perpendicular to the symmetry axis (parallel to the plane of the two equal points)?