THE ORIGIN AND EVOLUTION OF THE EARTH
The fascination with the night sky and celestial bodies like stars is a universal human experience that spans across cultures and ages. This curiosity has led to various theories and hypotheses about the origin of Earth and the universe as a whole. Below are some key points explaining the early theories concerning the origin of Earth and the broader universe.
The ‘Nebular Hypothesis’, originally proposed by Immanuel Kant and later revised by Laplace, posits that the solar system formed from a giant rotating cloud of gas and dust. According to this theory, the young Sun was at the centre of this cloud, and the planets formed from the material that didn’t fall into the Sun.
Both Schmidt and Weizsäcker updated the Nebular Hypothesis in the 1950s. While their theories differed in details, both agreed that the solar nebula surrounding the young Sun mainly consisted of hydrogen and helium, along with other particles commonly referred to as dust. The formation of planets, according to this revision, occurred through a process known as accretion — where particles in the rotating disk-shaped cloud gradually clumped together due to gravitational forces, friction, and collision.