Tycho Brahe had always insisted on the theory of celestial motion, but his extensive observations were used by Kepler to prove that the earth revolves around the sun.
In the 16th century, the Danish astronomical observer Tycho Brahe discovered a new star in the constellation Cassiopeia, and he observed it for more than ten months and saw the process of the star from bright to vanished, which broke the traditional theory that "the star does not change". Now we know that this is not the creation of a new star, but the process by which a star so dark that it is almost invisible before it disappears.
Tycho's attempts to discover the parallax effect of stars, the change in the orientation of stars caused by the Earth's orbit, were unsuccessful through accurate star position measurements. He then began to oppose Copernicus's theory of earth motion, and proposed a cosmic system in which the earth was stationary at the center of the universe, the planets orbited the sun, and the sun led the planets around the earth.
After Tycho's death, his assistant Kepler used the observations accumulated by Tycho for many years, carefully analyzed and studied, and proposed the three laws of planetary motion, namely Kepler's three laws, which laid the foundation for Newton's law of universal gravitation.
In 1609, Kepler proposed his first two laws of planetary motion in The New Astronomy. The first law is the law about the orbits of planets moving around the sun, holding that the orbit of each planet is an ellipse and that the sun is located on a focal point of this elliptical orbit. The second law is the law of the speed of the planets, which holds that the planets are closest to the sun, and the closest to the sun is the fastest, and vice versa, the distance between the planets and the sun is the same. Ten years later, he published the third law of planetary motion, which states that the farther a planet is from the sun, the longer its cycle, and the square of its period is proportional to the cube of the distance to the sun.
In addition, Kepler speculated that comets always have their tails away from the Sun because of the presence of a solar wind that blows them away, which is the first to be involved in the field of light pressure. Hotspot Engine Program