“Come and see the Earth rotate!”
This is the formula used by Léon Foucault in the invitations addressed to the public, during the installation of his pendulum at the Pantheon in Paris in 1851.
This experiment can be repeated as soon as a sufficiently high hanging point is available (3 meters is enough). This is the only way to highlight the rotation of the Earth, from Earth.
Everyone leaves with their photo in front of the pendulum.
Foucault’s pendulum in Le Panthéon, in Paris © Benjamin Gavaudo
Duration of activity: Observe the pendulum at several times of the day.
The group discussion and explanation may last longer or shorter, depending on the level and educational ambition. Some calculations are at Terminale S level.
Subjects: Mathematics, Physics
Level: All levels
Key messages:
- The Earth rotates
- Understanding the Coriolis “force,” which gives storms their shape