Galileo was observing

In 1581, there was a 17-year-old young man at the University of Pisa in Italy. He did not believe what teachers said like ordinary students. He liked to think independently and often asked professors some strange questions. For example, Aristotle's works are classics read as students. Every sentence in them is regarded as truth and no one doubts it. However, the young man said: Scientific truth needs to be tested through actual observation and scientific experiments, and not everything Aristotle said is necessarily correct. Look how arrogant he is! Therefore, everyone regarded him as an "arrogant student."

Not long after, people suddenly realized that this "arrogant student" turned out to be a genius. In his fifth year, he left school before receiving his diploma because he could not afford his tuition. But he came home soon. In 1586, he published the mathematical paper "Specific Gravity", which caused a sensation in the Italian mathematical community. In 1589, the University of Pisa hired the ungraduated student to return to the university to teach. In 1590, he published a long paper "On Gravity", which was the first to propose the law of free fall, arguing that no matter how big or heavy an object, in the process of free fall, except for the influence of air resistance, their accelerations are exactly the same, negating Aristotle's principle of weight, speed and lightness. In order to prove the law he proposed to the whole school, he gave a famous experiment on the Leaning Tower of Pisa. A ten-pound iron ball and a one-pound iron ball landed from the Leaning Tower at the same time. Practice proved the correctness of his theory.

This student was Galileo. He was born on February 15, 1564. It was with this "arrogant" courage to dare to explore and not blindly follow, and the spirit of practicing and dedicating himself to the pursuit of truth. Through perseverance, he made great achievements in physics, mathematics, astronomy and other scientific fields, and became one of the founders of modern natural sciences in Europe.

Galileo discovered the four moons of Jupiter