What if you could visualize the rotation of Earth without needing to take a trip to space? The Foucault Pendulum, located in the Science Museum’s Rotunda, is designed to demonstrate Earth’s rotation on its axis.

The Foucault Pendulum (pronounced pen·juh·luhm) was invented by French physicist Jean Foucault (pronounced Foo-koh) in 1851 to demonstrate the rotation of the Earth. We still use these impressive devices today for the same purpose.

The Pendulum consists of a wire and a heavy symmetrical bob which hangs from the top of the Rotunda.

The pendulum swings back and forth as the Earth rotates on its axis and knocks down the 79 pegs encircling the metal sphere. It takes 19 hours and 43 minutes to knock down all the pegs.

Come join in the anticipation of seeing the pendulum swing and the excitement when it knocks down a peg!

Access to this exhibit does not require Science Museum admission.