How was Leonardo da Vinci able to think so far "outside the box" that he envisaged developments in engineering, astronomy, and anatomy that were only realized centuries later? The list of da Vinci's "firsts" is astonishing: he asserted that "the sun does not move" more than a generation before Copernicus; he reasoned that fatty deposits in narrowed arteries were caused by an unhealthy diet; he drew the first designs for a parachute, armored car, machine gun, diving suit, helicopter, and a flying machine that anticipates the modern hang glider, not to mention history's first humanoid robot. NOVA joins Walter Isaacson, author of the acclaimed recent biography, on a journey to Italy to explore the impact of da Vinci's art on his science and his science on his art.