Isaac Newton believed everything in the physical universe could be described using mathematical relationships. His law of gravity explained why objects fall downwards, how the moon causes the tides, and why planets and comets orbit the sun. While his work has been added to over the years, his basic approach remains at the heart of the scientific worldview. Yet Newton also believed the universe was created to a precise and rational design—a design that was fully understood by the earliest people. Newton considered it his life's work to rediscover this knowledge. In chasing his impossible goal, Newton managed to contribute more to our understanding of the universe than anyone else in history.