Pendulum by Léon Foucault

Léon Foucault, Paris1851

Deutsches Museum

Deutsches Museum

In 1851, Léon Foucault used a pendulum in the Pantheon im Paris to prove the Earth’s rotation on its axis in relation of the fixed stars in the sky.
The pendulum is set in motion at 9.00 a.m. and then swings freely. You can see the progression of the Earth as the pendulum slowly swings towards the angles indicated on the floor. At the North or South Pole, at 90° latitude north and south, respectively, the perpendicular plane of swings of the pendulum changes in relation to the Earth’s surface. The Earth thus rotates beneath the plane of the pendulum’s suspension once every 24 hours.
At the Equator, 0° latitude, the rotation of the plane of the pendulum in relation to the Earth is an intermediate value within the extremes at the Pole and at the Equator. In Munich, the plane of the pendulum rotates by appproximately 11.15° per hour.
Pendulum wire length: 60 m
Mass of the pendulum ball: 30 kg
Demonstration starts at 9.00 a.m.

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  • Title: Pendulum by Léon Foucault
  • Creator: Léon Foucault, Paris
  • Date: 1851