Foucault pendulum with a 67-m-long wire from the dome of the Panthéon, Paris. The plane of the pendulum's swing rotated clockwise approximately 11.3° per hour, making a full circle in approximately 31.8 hours. The original bob used in 1851 at the Panthéon was moved in 1855 to the Conservatoire des Arts et Métiers in Paris. A second temporary installation was made for the 50th anniversary in 1902. During museum reconstruction in the 1990s, the original pendulum was temporarily displayed at the Panthéon (1995), but was later returned to the Musée des Arts et Métiers before it reopened in 2000. On April 6,
Foucault pendulum Earth, "F" is the component of the Coriolis force in the "x"-direction and "F" is the component of the Coriolis force in the "y"-direction. The restoring force, in the small-angle approximation, is given by Using Newton's laws of motion this leads to the system of equations Switching to complex coordinates , the equations read To first order in Ω/"ω" this equation has the solution If time is measured in days, then and the pendulum rotates by an angle of −2π sin("φ") during one day. Many physical systems precess in a similar manner to a Foucault pendulum. As early as 1836,