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
Foucault pendulum vector diagrams the pendulum is swinging or not. If the bob is not allowed to turn with the support-point one twist of the connecting wire will occur in one day at the pole. If the connection apparatus of the pendulum to the bob and to the support were in a fixed relationship (and the connection not allowed to twist, for example, using a rigid rod pinned into place between two sides of the support), then once the plane of the pendulum swing is established in one direction, that plane would be forced to turn with the support and connection. The Earth's rotation