The Foucault Pendulum: Unveiling Earth’s Rotation 🌎 The Foucault Pendulum is a visual demonstration of the Earth’s rotation. Named after Jean Bernard Leon Foucault, the French physicist who invented it, the Foucault Pendulum was first exhibited in 1851 at the World’s Fair in Paris Throughout the day, the direction of the pendulum’s swing appears to change. Actually, Earth is turning under the pendulum as it swings. At Houston’s latitude (30° N.) the pendulum will precess through 180° or halfway