Photo: Deutsches Museum | Reinhard Krause
The Foucault Pendulum
Standstill at 1117 km/h
Weather station, transmission tower, vantage point and home of the pendulum: the tower of the Deutsches Museum is much more than the building’s landmark. The entrance on the first floor is located in the transition between the Model Railway and Bridges and Hydraulic Engineering exhibitions. Right next to the elevator, you can see a Foucault pendulum in action.
On display is a 30-kilogram lead ball that swings slowly back and forth on a 60-meter wire cable. Below the ball is a circular disc three meters in diameter, which indicates the cardinal points and on which more than 60 movable cones are placed in a semicircle. The sphere always oscillates in the same plane. Nevertheless, after a few minutes it knocks over one cone after the other, thus proving that the earth is rotating – under the pendulum. And it doesn't do so slowly at all: At our latitudes, the Earth’s rotation has a speed of around 1117 kilometers per hour.
The phenomenon is not only clearly visible: “Together with an experienced musical instrument maker, our workshops have developed a sophisticated mechanism that ensures that we can now also hear this rotation. And to appeal to even more senses, there is a new demonstration on which the rotation can even be felt,” says Daniela Schneevoigt, the curator in charge.