How does Newton's law of gravitation support the heliocentric model?

Newton's law of gravitation supports the heliocentric model by explaining the elliptical orbits of planets around the sun.

Newton's law of universal gravitation states that every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. This law, combined with his laws of motion, provides a comprehensive explanation for the heliocentric model, which posits that the sun is at the centre of the solar system and the planets revolve around it in elliptical orbits.

The heliocentric model was first proposed by Nicolaus Copernicus in the 16th century, but it was not widely accepted until the 17th century, when Johannes Kepler refined it by introducing the concept of elliptical orbits. However, the reason why planets move in such orbits remained a mystery until Isaac Newton formulated his law of gravitation.

According to Newton's law, the force of gravity decreases with the square of the distance, which means that the gravitational pull of the sun on a planet is stronger when the planet is closer to the sun. This causes the planet to move faster when it is near the sun and slower when it is farther away, resulting in an elliptical orbit. Moreover, the law also explains why planets with larger masses have stronger gravitational pulls and therefore move in tighter orbits around the sun.

In addition, Newton's law of gravitation also supports the heliocentric model by explaining the phenomenon of planetary motion. According to his second law of motion, a body will move in a straight line at a constant speed unless acted upon by a force. In the case of a planet, the force of gravity from the sun constantly pulls it towards the sun, causing it to deviate from a straight line and move in an elliptical orbit instead.

In conclusion, Newton's law of gravitation provides a scientific basis for the heliocentric model by explaining the elliptical orbits of planets and the forces that cause them. It is a testament to the power of scientific theories that they can not only describe the natural world, but also predict its behaviour.