Foucault Pendulum

A **Foucault pendulum** was conceived as an experiment to demonstrate the rotation of the Earth. It is a tall pendulum free to **oscillate** in any **vertical plane**. The first Foucault pendulum exhibited to the public was in **February 1851** in the **Meridian Room** of the **Paris Observatory**. In this year it was well known that the Earth moved. From the Earth the pendulum will appear to change its direction of swing over time without any outside input. In fact, it is actually the Earth which is rotating, while the pendulum continues to swing in the same plane relative to the rest of the Universe.