Galileo Galilei

Galileo did more than anyone to make nature speak the language of mathematics. He found that falling bodies obey simple laws, built a telescope and saw mountains on the moon, moons around Jupiter, and the phases of Venus — evidence that the heavens were neither perfect nor turning around us. The book of nature, he wrote, is written in the characters of geometry. His defense of Copernicus brought him before the Inquisition, which forced him to recant and condemned him to house arrest for his last years. The method he modeled — measure, idealize, test — became the engine of modern science.