No One Is Quite Sure Why Ice Is Slippery
A thin, watery layer coating the surface of ice is what makes it slick. Despite a great deal of theorizing over the centuries, though, it isn't entirely clear why that layer forms.
Behold the Manifold, the Concept that Changed How Mathematicians View Space
In the mid-19th century, Bernhard Riemann conceived of a new way to think about mathematical spaces, providing the foundation for modern geometry and physics.