The Franklin Institute

The Franklin Institute’s four-story Foucault’s Pendulum mimics an experiment undertaken by French physicist Jean-Bernard-Leon Foucault early in 1851. The experiment proved the nature of the Earth’s daily rotation around its axis. The fact that the Earth is spinning and the pendulum is swinging creates this interesting effect. At 9:30 am, the museum starts the pendulum swinging in a North-South direction. During the day, the pendulum knocks down a peg every 20-25 minutes, making it appear to change direction. By 5:00 pm, half of the pegs have been knocked down.

Things to Do and See in Foucault’s Pendulum

  • Foucault Pendulum at The Franklin Institute
    See physics in action

    The pendulum swings all day starting at 9:30 am.

  • Foucault Pendulum at The Franklin Institute
    See a different view from another level

    The pendulum can be viewed from the 1st, 2nd, and 3rd floors of the science museum

Interactive Map



Map of the first floor, showing the locations of major, permanent exhibits, the Planetarium, and Foucault’s Pendulum.