earth-rotation

In 1851, Léon Foucault hung a 67-meter pendulum from the Pantheon dome and watched its plane rotate. Here is the physics of why that single swing proved Earth spins.

Earth spins at 1,674 km/h at the equator. If it suddenly stopped, supersonic winds would devastate the surface. If it slowed gradually, the consequences are still severe — a 6-month day, ocean redistribution, and a collapsing magnetic field.

At the equator, you're moving at 1,674 km/h because the Earth is rotating. You can't feel it. Here's the Newtonian mechanics and relativistic physics that explain why — and the real clues that reveal Earth's rotation.