Wherever you put it, Foucault's Pendulum swings from a motionless point while the earth rotates

beneath it. Every point of the universe is a fixed point: all you have to do is hang the Pendulum from it." Foucault's pendulum is an easy experiment demonstrating the Earth's rotation.

How does a Foucault pendulum keep swinging?

To keep the Foucault Pendulum going, one must replace the energy lost with each swing. ... This restores the energy lost during the swing and keeps the pendulum from stopping. It has no effect on the direction of the swing, and thus does not interfere with the demonstration that the earth is rotating.

How does Earth's rotation affect a pendulum?

And each time the pendulum swings; the Earth rotates a little more. ... You start the pendulum swinging in a perfect east-west direction. The Earth still rotates each time the weight goes through an arc, but now it's moving in exactly the same direction as the pendulum.