Explanation: Origin of the Earth

• A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the earth.
• One of the earlier and popular arguments was by German philosopher Immanuel Kant. Mathematician Laplace revised it in 1796. It is known as Nebular Hypothesis. The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, which was slowly rotating.
• Later in 1900, Chamberlain and Moulton considered that a wandering star approached the sun. As a result, a cigar-shaped extension of material was separated from the solar surface.
• As the passing star moved away, the material separated from the solar surface continued to revolve around the sun and it slowly condensed into planets.
• Sir James Jeans and later Sir Harold Jeffrey supported this argument. At a later date, the arguments considered of a companion to the sun to have been coexisting. These arguments are called binary theories.
• In 1950, Otto Schmidt in Russia and Carl Weizascar in Germany somewhat revised the ‘nebular hypothesis’, though differing in details. They considered that the sun was surrounded by solar nebula containing mostly the hydrogen and helium along with what may be termed as dust.
• The friction and collision of particles led to formation of a disk-shaped cloud and the planets were formed through the process of accretion.

Source: NCERT Class 11