Earth's rotation Foucault in 1851, which consisted of a lead-filled brass sphere suspended from the top of the Panthéon in Paris. Because of the Earth's rotation under the swinging pendulum, the pendulum's plane of oscillation appears to rotate at a rate depending on latitude. At the latitude of Paris the predicted and observed shift was about clockwise per hour. Foucault pendulums now swing in museums around the world. Earth's rotation period relative to the Sun (solar noon to solar noon) is its "true solar day" or "apparent solar day". It depends on the Earth's orbital motion and is thus affected by changes
Foucault pendulum vector diagrams with increasing latitude). The plane of the pendulum swing, however, is independent of the surface velocity vectors underneath the swing since there is only one point of connection. The point of connection is configured such that the plane of pendulum swing is free to swing in any direction in relation to the structure of the connection point. The pendulum swing at the poles remains aligned toward a star if not forced to rotate with the support. As a result, it is observable that the Earth turns underneath the plane of swing of the pendulum. The reason the rotation of the