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You’ve probably seen a Foucault pendulum in a museum. This Victorian-era science demonstration is named after physicist Léon Foucault and shows how the Earth rotates compared to a pendulum moving in a fixed plane. [RyanCreates] shows you how you can make your own , and it is surprisingly simple.

All you need is a heavy weight like a small mushroom anchor, fishing line, and a swivel — all things you can pick up at any sporting goods store. You’ll need a way to suspend it all, such as an eye hook in the ceiling.

In addition to the mechanical parts, the build calls for a camera to record the results and a lighter or other source of flame. The reason? To release the pendulum, you burn a thread that prevents it from swinging. This allows for a clean release with no sideways force.

The amount of your rotation depends on your latitude. At 33 degrees north, for example, you can expect 360*sin(33)/24 or 8.17 degrees per hour of rotation.…