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 vectors on opposite sides of the pendulum. The evaluation is to identify whether the vectors on each side of the pendulum swing are 1) balanced in the same direction, 2) acting in the same plane, or 3) unbalanced or in opposing directions. If the vector components on opposite sides of the pendulum swing are balanced in the same direction or act in the same plane of the pendulum then the rotation of the Earth will not be observable in relation to the swing of the pendulum. If the plane of the pendulum swing establishes the "x"-"y" plane then the z-component