Earth’s Rotation Day 2024: Learn about Foucault Pendulum, day-night cycle

The world celebrates Earth’s Rotation Day on January 8 every year to commemorate the famous scientific demonstration by the French physicist Leon Foucault in 1851 to prove that the earth rotates on its axis.

Foucault Pendulum demonstration

Foucault used a pendulum, referred to since then as the Foucault Pendulum, to provide visual proof of the earth’s rotation. A long and heavy pendulum suspended from the roof of a high circular building, the Pantheon in Paris, was observed over a period of time, showing that its plane of oscillation rotated. This demonstration proved that the oscillation of the pendulum could only be explained by the earth rotating beneath it. It was the first simple, direct experiment to prove the theory.

Cause of day-night cycle

The earth’s rotation around its own axis causes day and night, and the change of seasons. It is the reason for our cycle of sleeping and waking. Scientists talk about a hypothetical line that connects the north pole and the south pole which determines the axis around which the earth rotates.

Foucault Pendulums displayed around the world

The Foucault Pendulum is displayed in museums and universities all over the world for people to observe and understand this scientific fact. The United Nations General Assembly building in New York also has one. There are about 11 locations in India where the Foucault Pendulum is displayed, including the New Parliament Building in New Delhi.

Earth’s Rotation Day serves to remind us about the manifold mysteries of our universe and should encourage us to explore and learn more about the planet we live on and the scientific explanations of everyday occurrences.