Galileo Galilei was an influential Italian scientist during the 1500s-1600s who made important contributions to the fields of motion, astronomy, and material strength classification. He accepted Copernicus' heliocentric model of the solar system and helped convert natural philosophy from a verbal to a more mathematical and experiment-based approach. The document provides biographical details about Galileo's background and career accomplishments as a philosopher, astronomer, and mathematician who helped advance scientific thought and methods.