Léon Foucault Léon Foucault Jean Bernard Léon Foucault (; 18 September 1819 – 11 February 1868) was a French physicist best known for his demonstration of the Foucault pendulum, a device demonstrating the effect of the Earth's rotation. He also made an early measurement of the speed of light, discovered eddy currents, and is credited with naming the gyroscope. Foucault was the son of a publisher in Paris, where he was born on 18 September 1819. After an education received chiefly at home, he studied medicine, which he abandoned in favour of physics due to a blood phobia. He first directed his
Foucault pendulum vector diagrams time increases because the central axis of the pendulum is aligned with the axis of rotation of the Earth at the North Pole and then the angle of misalignment increases as the latitude decreases to the point of perpendicularity at the Equator. The angular velocity in relation to the rotation of the Earth's axis that is imparted to the pendulum bob decreases with the cosine of the degree of misalignment of the central axis of the pendulum in comparison to the axis of rotation of the Earth. There are zero degrees of misalignment at the North Pole and the cosine