Foucault Pendulums Prove Earth's Rotation?

A Foucault Pendulum shows that Earth is turning around like a spinning top.

Imagine you're on a merry-go-round at the park. When it spins, everything on it moves in a circle, but if you drop a ball, it seems to go straight away from you instead of staying with the spin. That’s because the ball keeps moving in the same direction while the merry-go-round turns underneath it.

A Foucault Pendulum works like that ball on the merry-go-round. It swings back and forth in one line, but if Earth is turning, the pendulum seems to change direction slowly over time. That’s because Earth is spinning under it, just like the merry-go-round spins under the ball.

Think of the pendulum as a clock that only swings left and right. If Earth wasn’t turning, the pendulum would always swing in the same line. But since Earth turns, like a giant spinning top, the direction of the pendulum’s swing appears to shift, showing Earth is moving.

This slow change lets scientists know Earth spins without needing a telescope or rocket, just a clever swinging rope and some patience!