science
A soap bubble is a small machine for solving a difficult mathematical problem: find the surface of minimum area enclosing a given volume. The fact that bubbles solve this problem instantly, by physics, has occupied mathematicians for two centuries — from Plateau's experiments with iron-wire frame...
history
For 2000 years, philosophers insisted nature abhors a vacuum. Then a student of Galileo built a tube of mercury in 1643 and showed that the abhorrence was a mistake. The history of vacuum is the history of the slow recognition that emptiness is not what we thought it was.
science
The standard schoolroom answer (the moon pulls the water up) is incomplete enough to be misleading. The full answer involves differential gravity, two bulges in opposite hemispheres, the moon's slow recession from Earth at 3.8 cm per year, and a harmonic decomposition due to a Liverpool as
science
Every snowflake is six-sided. The reason is buried in the geometry of how water molecules pack into ice. The history of how this was discovered involves a Vermont farmer with a microscope and 5000 photographs that changed crystallography.