Explanation: 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.

Source: NCERT – Fundamental of Physical Geography