Foucault’s Pendulum Time Lapse

Even though you can’t feel it, the Earth is turning under your feet, causing the Sun, the moon, and the stars to rise and set in the sky. We can also demonstrate this with Foucault’s Pendulum. Leon Foucault was a French physicist who, in 1851, was able to demonstrate the Earth’s rotation by swinging a heavy mass at the end of a long cable. Over the course of a day, the direction the pendulum swings seems to change, slowly moving in a full circle. What we see is actually the earth turning beneath the pendulum. The speed at which the pendulum precesses depends on its latitude. Here at the Orange Coast College Planetarium, with a latitude of , our pendulum makes a complete 360 degree precession about once every 43 hours. video credit: Brett McNevin