## Foucault’s Pendulum Proves Earth is Rotating Sphere

Foucault’s pendulum proves Earth’s rotation. In the Northern Hemisphere, the pendulum rotates clockwise. In the Southern Hemisphere, it rotates counterclockwise. The pendulum turns faster if it is closer to the pole. On the Equator, the pendulum does not rotate.

Flat-Earthers invented various excuses to discredit Foucault’s pendulum. In reality, anyone not near the Equator can easily repeat the experiment, and it will give the expected result.

## Misconception and Strawman Arguments About Foucault’s Pendulum

The Coriolis effect acts on objects moving closer to or away from Earth’s axis of rotation. A swinging pendulum does that continuously while staying in the same place. Foucault’s pendulum is built very large to swing for a very long time so that we can observe the slow precession of the pendulum caused by Earth’s rotation.

Earth’s rotation does not cause a pendulum at rest to begin swinging, and flat-Earthers use that as “proof” that Foucault’s pendulums are manipulated. In reality, nobody claims the swinging motion of Foucault’s pendulum is caused by Earth’s rotation. The fact that Earth’s rotation does not cause a pendulum to swing does not disprove Earth’s rotation or the Coriolis effect.

## Foucault Gyroscope

In 1851, Léon Foucault used a pendulum to demonstrate the rotation of the Earth. Despite his success, he was not fully satisfied with the pendulum experiment because of the dependency on the sine of latitude, which the public found difficult to understand. He later designed a device which he named ‘gyroscope.’

A spinning gyroscope keeps a constant axis of rotation in space, so it should slowly rotate with respect to an observer attached to the rotating Earth. The challenge was technical; it would need to have minimal friction, and it has to be able to spin for a sufficient duration so that the precession due to Earth’s rotation can be observed.