Galileo Galilei is known by his first name. He was born on February 15, 1564. He was born in Pisa, Italy, to Vincenzio and Giulia Galilei. His father was a music teacher. He was ten years old when he and his family settled in Florence, Italy, in 1574. He was seventeen when he began studying medicine at the University of Pisa in 1581. He was not, however, very interested in the subject and eventually convinced his father to let him go. He then spent some time as a mathematics teacher. He began experimenting with pendulums, balls and toy boats. He became a professor of mathematics at the University of Pisa in 1589. He also taught astronomy and studied motion. “Stories tell that Galileo dropped heavy and light weights from the Leaning Tower of Pisa. This showed that objects of different weights fell at the same speed. Galileo tested this by dropping different things from the same height. (Lin, p. 10) In 1592 he moved to the University of Padua as a professor of mathematics. He stayed there for 18 years to continue his study of movement. He also studied the effect of heat on liquids and developed a simple thermometer. (By...