II.

Leonardo da Vinci

Leonardo is regarded as the consummate Renaissance man not primarily for his scientific accomplishments but because of his extraordinary range of achievements. Leonardo was a painter, sculptor, engineer, architect, physicist, biologist, and philosopher—and he was outstanding in each of these fields. Science influenced all of Leonardo’s activities; he believed in observing nature and carrying out experiments. As a painter, Leonardo studied the laws of optics and the optical structure of the eye; he studied human anatomy with the thoroughness of a medical surgeon to understand how to paint the torso. Leonardo’s ability to solve physics problems in the fields of static (stationary) and dynamic (moving) mechanics fortified his civil and military engineering work.

Leonardo excelled at physics. He anticipated the principle of inertia, which would be demonstrated by Galileo nearly a century later. The inertia principle is the idea that an isolated body, not in contact with anything, will continue moving at a constant velocity forever. Understanding this concept required deep insight since it is not at all easy to imagine an abstract idea such as an “isolated body.” Leonardo knew that the speed of a falling body increases over time. He knew that perpetual motion was impossible as a source of power, and he invented a mathematical scheme for proving the law of the lever. Leonardo worked on the flow of water through pipes, designing an irrigation system and channels. He studied wave motion on water and extended this study to waves in the air and the laws of sound.

Leonardo dismissed with contempt all the work of alchemists, astrologers, and magicians. To him, nature was orderly and subject to logical laws. In most of his scientific work, Leonardo was 100 years ahead of his time.