Galileo was born in Pisa， Italy（意大利比萨） in 1564. He liked drawing and making things. He was the oldest child in his family. He made many toys for his younger sisters and brothers. At the age of 17， Galileo went to study in the University of Pisa（比薩大学）. Because of his father’s wish（希望）， Galileo learned to be a doctor. But he was not very interested in medicine（医学）.
　　Galileo’s favorite place in the university was the library. He often went there to read books. He studied Math and Physics there on his own.
　　Galileo didn’t finish his study at the University of Pisa because his family was too poor. But he kept on（继续） studying on his own. He  published（发表） many papers（论文） and got a lot of honors（荣誉）. Then he got a job at the University of Pisa as a professor（教授）. He was very excited. He put all his energy（精力） into science. After three years， Galileo got an offer（获得工作机会） from the University of Padua（帕多瓦大学）.
　　Galileo gave all of his life to science. In his later life， he was blind（失明的）. But he never stopped his research（研究）.
　　Galileo did a great experiment（实验） on the Leaning Tower of Pisa（比萨斜塔） in 1590. At that time， people believed if two different things fell（落下） at the same time， the heavier one would land（着地） first. Galileo dropped（扔下） two iron（铁） balls of different weights（重量） from the tower. They landed on the ground at the same time. Galileo corrected（改正） people from a 1，900-year-old wrong idea.
　　● Law of a Free Falling Body（自由落体定律）
　　● The Earth is not the center of the universe（宇宙）. It is rotating（旋转） around the sun.
　　● A very useful invention（发明）——Galilean telescope（伽利略望远镜）. It helps people look into space.
　　Galileo found（发现） the four moons of Jupiter（木星的卫星）. To remember him， people call them Galilean satellites（伽利略卫星）.