Final answer:
The spinning of the Earth on its axis is called rotation, responsible for day and night, and takes about 24 hours to complete. The Earth also undergoes precession, a slow wobble of its axis, occurring over a 26,000-year cycle.
Step-by-step explanation:
The spinning of the Earth on its axis is called rotation. This rotation is why we experience day and night. Each complete turn takes approximately 24 hours, which we refer to as a day. This spinning movement is similar to that of a spinning top or a gyroscope. Earth not only rotates on its axis but also exhibits another motion called precession. Precession refers to the slow wobble of Earth's axis as it spins, which is comparable to the wobble seen in a slowing spinning top. This motion occurs over a cycle of approximately 26,000 years and leads to changes in the celestial coordinates and affects seasonal timings over long periods.
The turning of the Earth was spectacularly demonstrated in the 19th century by physicist Jean Foucault, using an enormous pendulum, known as the Foucault pendulum. This experiment proved that the Earth is rotating beneath us. As a result, celestial objects such as stars appear to rise and set due to Earth's rotation. Additionally, Earth acts like a gigantic gyroscope with its angular momentum along its axis, currently pointing towards Polaris, the North Star.