Earth's Rotation Day

Léon Foucault was a French mathematician and astronomer who is best known for his invention of a pendulum which demonstrates the rotation of the earth. But he was also a master inventor, and he contributed to many different branches of science.

The pendulum is not a perpetual motion machine. The Foucault Pendulum is named for the French physicist Jean Foucault (pronounced "Foo-koh), who first used it in 1851 to demonstrate the rotation of the earth. It was the first satisfactory demonstration of the earth's rotation using laboratory apparatus rather than astronomical observations.

In fact, he’s said to have fainted on seeing blood for the first time. Not surprisingly, he dropped out of medical school. Fortunately, he had other talents, and his aptitude for mechanics and invention was soon recognized. With almost no formal training, he succeeded in building a boat, a mechanical telegraph, and a steam engine.