Foucault’s Pendulum

It is a pendulum free to swing in any direction for about 24 hours. Foucault’s first pendulum was presented to the public in 1851, and consisted of a 28 kg sphere suspended from the dome of the Pantheon in Paris with a 67 m long wire. In an inertial system, it would always have drawn lines in the same direction, but it did not.

At any latitude of the Earth, except along the equator line, the pendulum’s plane of oscillation is observed to rotate. At the North Pole and the South Pole, rotation occurs on a sidereal day: the plane of oscillation remains stationary while the Earth rotates, in accordance with Newton’s law of motion.

Foucault’s pendulum is an easy experiment demonstrating the Earth’s rotation. … At the north or south pole, the pendulum is moving in a fixed plane (if we disregard the fact that the Earth is also revolving through space), so the plane of the pendulum seems to rotate through 360° as the Earth makes one full rotation.

Labtrek produces Foucault pendulums for universities, exhibits, science festivals. The main feature of our pendulums is that they do not require periodic maintenance or calibration. We have a pendulum swinging unsupervised since 2006 in “Palazzo della Ragione” Padua, Italy.