Final answer:
Foucault's pendulum proved that the Earth is rotating on its axis. This was shown by the pendulum's shifting plane of oscillation while knocking over sequential targets, indicating Earth's movement beneath the fixed oscillation plane. This unambiguous demonstration confirmed Earth's rotation independently of celestial observations.
Step-by-step explanation:
The French physicist Jean Foucault set up a large pendulum in the Pantheon in Paris in 1851, demonstrated and proved that the Earth is turning on its axis
As the pendulum swung, its plane of oscillation shifted gradually, knocking over targets in a circle over the course of several hours, which showed that the pendulum’s plane remained fixed in space while the Earth turned beneath it. This provided clear evidence of Earth's rotation, independent of observations of the sky.
Everyday examples of pendulums are seen in old-fashioned clocks and children’s swings. These devices exhibit simple harmonic motion when their displacements are small.
The Foucault pendulum is a sophisticated and large-scale example that demonstrates Earth's rotation in a unique way, contrasting with non-pendulum clocks like wristwatches that use a balance wheel and spring for timekeeping.
Other ways to prove that Earth is turning could involve studying the effects of the spinning Earth on the oceans and the atmosphere, such as the phenomenon known as the Coriolis effect.