Foucault, Jean Bernard Léon

views updated

Foucault, Jean Bernard Léon (1819–68) French physician and physicist who invented the gyroscope. He used a pendulum (Foucault's pendulum) to prove that the Earth spins on its axis and devised a method to measure the absolute velocity of light (1850). With Armand Fizeau, he took the first clear photograph of the Sun. He also noted the occurrence of eddy currents, which became known as Foucault currents.

More From encyclopedia.com