What Is Kepler's Third Law?

Kepler's third law is also called the law of planetary motion. The common expression of Kepler's third law is: for all planets orbiting the ellipse orbit centered on the sun , the ratio of the cube of the semi-major axis of the ellipse orbit to the square of the period is constant.

Kepler's original statement in Cosmic Harmony : all planets orbiting an ellipse orbiting the sun

The law of gravity is derived using Kepler's third law, so it cannot be used anymore.

Conditions of establishment

Kepler's law is a universal law that applies to everything

Kepler's law challenged the Aristotles and Ptolemies to astronomy and physics. His argument broke the old ideas in astronomy and physics left by Aristotle.

An important feat of Kepler's law was that in 1684, Newton deciphered the secret of astronomical motion, the law of universal gravitation, based on Kepler's law and the law of motion he studied. ^[13]

Kepler's Three Laws is a revolution in astronomy. It destroyed Ptolemy's complicated universe system, perfected and simplified Copernicus' heliocentric universe system. It is of great inspiration to future generations to find out the mystery of the structure of the solar system, and it provides important hints for the establishment of classical mechanics and the discovery of Newton's law of universal gravitation. ^{[twenty three]}