Dava Sobel, the author of Galileo's Daughter: A Historical Memoir of Science, Faith, and Love, contributed this essay, which uses video and text to recount Galileo's contributions to science and to explain how he reconciled his religious beliefs with his sometimes-contradictory experimental results. The essay also includes insights into the combativeness that existed between natural philosophers in the Aristotelian tradition and mathematically-oriented physicists like Galileo. Putting Galileo's life in perspective -- his inventiveness served him well in an age of technological infancy -- it's easy to understand why Albert Einstein, in honoring both his contributions to astronomy and physics and his role as pioneer and visionary, called Galileo the "father" of modern science.