A Foucault pendulum is a spherical pendulum can swing freely in any vertical plane and able to oscillate for a long time (hours). Is used to demonstrate the rotation of the Earth and the Coriolis effect. It is named after its inventor, Léon Foucault.

There is a Foucault pendulum in the great entrance hall of the United Nations building in New York, and is often found in major science museums.

This photograph shows the pendulum in the Pantheon in Paris. Its historical importance lies in that he became the first demonstration in 1851. The pendulum was attached to the dome of the Pantheon in Paris, measuring 67 m and had a mass of 28 kg. Once released, the pendulum swung for 6 h. The period is 16.5 s, the pendulum is deflected 11 ° per hour. His full spin cycle takes just over 32 hours.

On April 6, 2010, the pendulum cable broke, causing irreparable damage to the pendulum and the marble floor of the famous cemetery.