Galileo was a great Italian scientist in the17th century. When he was studying at school, his classmates called him "debater". His questions are unusual and often make it difficult for teachers to answer them.

At that time, people who studied science believed Aristotle and regarded the words of the Greek philosopher more than 2,000 years ago as unchangeable truth. If someone doubts Aristotle, people will blame him: "What do you mean? Is it necessary to violate the truth of mankind? "

Aristotle once said, "Two iron balls, one weighing 10 pounds and the other weighing 10 pounds, fall from a height at the same time. Those who weigh 10 pounds must land first, and the speed is 10 pounds 10 times. " This sentence made Galileo doubt. He thought: if this sentence is right, then tie two iron balls together, and the slow one will slow down the fast one, and the falling speed should be slower than the iron ball of 10 kg; However, if the two iron balls tied together are regarded as a whole, their weight is 1 1 lb, and the falling speed should be faster than that of the iron ball with1lb. In this way, two opposite conclusions can be drawn from one fact. How do you explain this?

Galileo repeated many experiments with this question, and the results proved that Aristotle's statement was indeed wrong. Two iron balls with different weights fall from a height at the same time and always land at the same time. The speed at which the iron ball falls has nothing to do with its weight. Galileo was only 25 years old and had become a professor of mathematics. He announced the results of the experiment to the students, and announced that he would do a public experiment on the leaning tower of Pisa.

The news spread quickly. On that day, many people gathered around the leaning tower to see who was the winner of this question: Aristotle, an ancient philosopher, or Galileo, a young math professor? Some said, "This young man is so bold that he wants to find fault with Aristotle!" Some said, "After a while, he won't be stubborn. The fact is ruthless and will make him lose face! " "

Galileo appeared at the top of the leaning tower. He holds a 1 lb iron ball in his right hand and a1lb iron ball in his left hand. Two iron balls were released at the same time and fell from the air. After a while, people around the leaning tower couldn't help shouting in surprise, because everyone saw two iron balls fall to the ground at the same time, just like Galileo said. At this time, everyone realized that everything said by a great philosopher like Aristotle was not right.