Galileo Galilei, though famous for his scientific achievements in astronomy, mathematics, and physics and infamous for his controversy with the church was, in fact, a devout Christian who saw not a divorce of religion and science but only a healthy marriage: "God is known by nature in his works, and by doctrine in his revealed word."

Galileo, who died this week in 1642, never got his university degree. He studied for four years and dropped out, then studied on his own for two years, living as a tutor and publishing solutions to complex problems. This brilliance got him the chair of mathematics at the University of Pisa, where he immediately made enemies.

The "natural philosophers" of his day made their discoveries debating the works of Aristotle. Galileo believed in observing nature under controlled conditions and describing the results mathematically. This difference alone created friction, but Galileo humiliated his enemies with public demonstrations of their errors—for example, Galileo proved, contra Aristotle, that bodies of different weights would fall at the same velocity. His enemies ran him off in two years.

In 1609 Galileo heard of a device to make distant objects appear closer: a telescope. The applications of such an instrument were immediately obvious to him. He quickly put together a telescope and displayed it to the Venetian Senate, which was so impressed, it immediately doubled his salary. That winter he turned his telescope on the sky and made some astounding discoveries. In complete contravention of accepted beliefs, he saw that the moon was not a smooth sphere, that Jupiter had moons, and that Venus had phases, indicating it orbited the sun. He published a small pamphlet describing his observations in 1610. ...