Foucault pendulum Foucault pendulum The Foucault pendulum ( ; ) or Foucault's pendulum is a simple device named after French physicist Léon Foucault and conceived as an experiment to demonstrate the Earth's rotation. The pendulum was introduced in 1851 and was the first experiment to give simple, direct evidence of the earth's rotation. Today, Foucault pendulums are popular displays in science museums and universities. The first public exhibition of a Foucault pendulum took place in February 1851 in the Meridian of the Paris Observatory. A few weeks later, Foucault made his most famous pendulum when he suspended a 28-kg brass-coated lead bob
Panthéon cross of the dome, which was retained in compromise, is again visible during the current major restoration project. In 1851, physicist Léon Foucault demonstrated the rotation of the Earth by constructing a Foucault pendulum beneath the central dome. The original sphere from the pendulum was temporarily displayed at the Panthéon in the 1990s (starting in 1995) during renovations at the Musée des Arts et Métiers. The original pendulum was later returned to the Musée des Arts et Métiers, and a copy is now displayed at the Panthéon. It has been listed since 1920 as a "monument historique" by the French