Kepler's law is the law about planetary motion discovered by Kepler. He published two laws on planetary motion in his "New Astronomy" in 1609, and in 1618, he discovered the third law. Kepler was fortunate to have the very precise astronomical data observed and collected by the famous Danish astronomer Tycho Brahe for more than 20 years. Around 1605, based on Brahe’s planetary position data and using Copernicus’s theory of uniform circular motion, it was found through 4 years of calculations that Tycho’s observed data and calculations had an error of 8’. Kepler firmly believed Tycho His data is correct, so he questioned the "perfect" movement of God (uniform circular motion). After nearly 6 years of extensive calculations, Kepler came up with the first law and the second law. After another 10 years After a lot of calculations, the third law was reached. Kepler's laws gave Aristotelian and Ptolemaic great challenges in astronomy and physics. He advocated that the earth is constantly moving; the planetary orbit is not an epicycle, but an ellipse; the speed of the planet's revolution is not constant. These arguments greatly shaken the astronomy and physics at that time. After almost a century of researching the star and moon and forgetting to sleep and eat, physicists are finally able to explain the truth with physical theories. Newton used his second law and the law of universal gravitation to rigorously prove Kepler's law in mathematics and let people understand its physical meaning.
