Isaac Newton was born in 1643, and was a physicist and mathematician. He developed the principles of modern physics, including the laws of motion, and is credited as one of the great minds of the 17th century Scientific Revolution. Newton made discoveries in optics, motion and mathematics. His momentous book on physics, Principia, contains information on nearly all of the essential concepts of physics ultimately helping him to explain the laws of motion and the theory of gravity. The Apple Myth, which there are many of, according to this common myth, Newton was sitting under an apple tree when a fruit fell and hit him on the head, inspiring him to suddenly come up with the theory of gravity. While there is no evidence that the apple actually hit Newton on the head, he did see an apple fall from a tree, leading him to wonder why it fell straight down and not at an angle. Consequently, he began exploring the theories of motion and gravity.