The Foucault pendulum at the Griffith Observatory in Los Angeles

© GIPhotoStock/Science Photo Library

The Foucault pendulum at the Griffith Observatory in Los Angeles

French physicist Léon Foucault first demonstrated his pendulum experiment in 1851 in Paris. Since then, it’s become a mainstay of science centers and museums around the world. His simple, elegant device—little more than a weight on a wire, with suspending hardware that allows the pendulum to swing in any direction—is considered the first to prove the rotation of the Earth on its axis. This Foucault pendulum swings in the central rotunda of the Griffith Observatory in Los Angeles.