552 years ago today, on February 19, 1473 (January 23, 1473, the 1473 lunar calendar), Copernicus, the founder of the sun-centered theory, was born. Copernicus likes to have a small fish port on the border of Poland and on the coast of the Baltic Sea. It was an ancient castle called Fromberg. In the northwest corner of the castle, there is an arrow tower. This arrow tower is the observatory where the world-famous astronomer Copernicus observed astronomy, and the famous "Copernicus Tower" in the history of astronomy. Since the 17th century, it has been preserved as a sacred place for astronomy to this day. Every year, thousands of scientific workers come to pay homage to this scientist's great hard work for mankind. On February 19, 1473, Copernicus, the great astronomer and founder of the theory of earth motion, was born at the home of an ordinary businessman in the city of Torun, Poland. In 1491, he went to the University of Krakow, the then capital of Poland, to study astronomy and mathematics. In 1496, he followed the advice of his uncle Ukas and went to Italy to study Canon Law. However, during his stay in Italy, he never stopped studying astronomy for a moment. He conducted countless astronomical observations and measurements and collected a large amount of astronomical data. In 1506, Copernicus returned to his motherland. He first lived in Helsberg, the official residence of his uncle, Bishop Ucas, sorted out the astronomical data he collected from Italy and wrote "On the Hypothesis of the Movement of Celestial Bodies", which is actually an outline of the "Heliocentric Theory". When his uncle died of illness in 1912, he moved to Fort Fromberg and stayed there until his death. In Fort Fromberg, he bought the arrow tower and built a small observatory. Whether in midsummer or in severe winter, he used homemade crude instruments to observe astronomy day and night. He ignored the persecution of the Church and the surveillance of spies and spies. Even when the war broke out between Poland and the Teutonic Knights in 1519 and the castle was full of blood and fire, Copernicus still climbed to the turret every day and insisted on his astronomical observation work. In this way, he spent his life completing the observation of celestial bodies and writing the immortal masterpiece-"Movement of Celestial Bodies". This is an epoch-making work. Its publication began a new era of human cosmology. Engels called it the "Declaration of Independence" that liberated natural science from religious theology. Copernicus Monument