eer of the 16th century. His grasp of the connection between art and science is glimpsed in this quotation: ôStudy the science of art. Study the art of science. Develop your sensesùespecially learn how to see. Realize that everything connects to everything else" (1). Da Vinci followed his own advice. He dissected corpses and made intensive nature studies, sketching everything from plants to people. His sketchbooks are filled with nature studies and imaginative sketches of futuristic machines and other inventions. His comprehension of the scientific principles underlying his inventions is no doubt due in part to his avid observation of everything around him and his precise documentation of everything he saw and thought about. His drawings illustrating rolling friction led to his invention of the standard cage that prevents balls and rollers from rubbing against each other through the leveraging of the lift:drag ratio (2, Fig. 1). His understanding of hydraulics, his scheme for canalizing rivers, and the large number of ingenious machines and gadgets he devised (including a machine gun, a parachute, an underwater diving suit, and several flying devices, among scores of others), stand the test of todayÆs science. In recent years on a Science Channel program, da VinciÆs drawings were used to build actual prototypes of his ideasàand they worked (3).
In the synergy that has often precipitated great advances throughout history, da VinciÆs ideas and art came at a time when the world was uniquely poised to receive themùat the beginning of the scientific renaissance that heralded the upcoming Scientific Revolution. Some of the concepts that fascinated da Vinci were part of the scientific thought of that day. The categories of motion were extremely important in pre-Newtonian science; perfect circular motion, for example, was viewed as ôan unquestioned cosmological principle, which gave consistency to the whole theory of astr...