Kepler (JohannesKepler, 1571-1630), a German astronomer. Kepler was born on December 27, 1571 in a small German citizen family. He suffered a lot of misfortune as soon as he came into the world. Smallpox made him pockmarked, and scarlet fever damaged his eyes.
At the age of 17, Kepler entered the University of Tübingen to study theology, and in 1591 he received a master's degree in theology. But because his father was in debt, he had to drop out of school. Because of his frailty and sickness, his parents thought he was only suitable to be a pastor, because his career was easier. However, Kepler was very talented in mathematics. After he learned some theories about natural sciences, he discarded the idea of being a pastor and finally taught natural sciences at a university in Austria.
In 1600, the 30-year-old Kepler wrote a letter to Tycho, a Danish astronomer who had never known him before. He told Tycho about his achievements and ideas in astronomy. After Tycho saw it, he was amazed at Kepler's talent and immediately wrote to invite him to be his assistant. But only 10 months after Kepler came to Tycho, the old man died. Kepler inherited the very valuable information left by the old man, including the old man's observation of the movement of Mars.
Kepler used Tycho's accumulated observational data for many years to carefully analyze and study, and found that planets move along elliptical orbits, and proposed three laws of planetary motion (ie Kepler's law), which laid the foundation for Newton's discovery of the law of universal gravitation.
Based on Tycho's work, Kepler compiled a "Rudolph Table of Stars" after a lot of calculations, which lists the positions of 1,005 stars. This catalog is much more accurate than other catalogs, so until the mid-eighteenth century, the "Rudolph's Catalog" was still regarded as a treasure by astronomers and navigators, and its form remained almost unchanged to this day.
Kepler's main works include "Mystery of the Universe", "Optics", "Universal Harmony", "A Summary of Copernicus' Astronomy", "Comet Theory" and "The Strange Celestial Phenomenon in 1631". Among them, in "The Harmony of the Universe", Kepler found the simplest world system, requiring only 7 ellipses to describe the system of celestial motion; in "Theory of Comets", he pointed out that the tail of comets is always back The setting of the sun is caused by the sun repelling the material of the comet head. This is the correct prediction for the existence of radiation pressure half a century ago; in addition, Kepler also discovered the approximate law of atmospheric refraction. In order to commemorate Kepler's achievements, the International Astronomical Union decided to name the 1134 asteroid Kepler.