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What in the devil is a Foucault Pendulum?

Named for the French physicist Jean Foucault (pronounced "foo-koh) who first used it in 1851 as the first satisfactory demonstration of the earth's rotation using laboratory apparatus rather than astronomical observations.  Setting pins on the floor in specific locations, the pendulum is set in motion, knocking over the pins as the earth spins beneath the pendulum.

Click here to see a demonstration of the pendulum in action as Captain Jim and crew tested the new atrium, tower, and pendulum as the museum expanded.  We hope you'll join us to see the completed project!

Galileo first developed the pendulum in 1581 to help clocks keep regular time. He noticed the chandelier swaying in the cathedral and applied it to a useful purpose-TIMING.

Leon Foucault's famous pendulum in 1851 proved the earth's rotation by the plane of the pendulum's swing rotating clockwise 11° per hour, making a full circle in 32.7 hours.

Foucault made his most famous pendulum when he suspended a 28 kg brass-coated lead bob with a 67 metre long wire from the dome of the Panthéon, Paris.

At the North Pole or the plane of oscillation of a pendulum remains fixed relative to the distant masses of the universe while Earth rotates underneath it, taking one sidereal day to complete a rotation.

The animation describes the motion of a Foucault Pendulum at a latitude of 30°N. The plane of oscillation rotates by an angle of −180° during one day, so after two days the plane returns to its original orientation.

So, relative to Earth, the plane of oscillation of a pendulum at the North Pole undergoes a full clockwise rotation in one day; a pendulum at the South Pole rotates counterclockwise.

Leon Foucault was best known for his demonstration of the Foucault pendulum, He also made an early measurement of the speed of light, discovered eddy currents, and is credited with naming the gyroscope.