Leonardo’s Visualization of gravity as a form of acceleration

With limited measurement and mathematical tools, Leonardo da Vinci displays ingenious problem-solving. Here, we report a brilliant combination of Leonardo’s thought and physical experiments on the nature of acceleration of falling objects. In his note, Leonardo recorded that if a water-pouring vase moves transversally, mimicking the trajectory of a falling object, it generates an isosceles orthogonal triangle composed of falling material lining up as the hypotenuse and the vase trajectory forming one of the legs. On the hypotenuse, Leonardo wrote Equatione di Moti, or equalization of motions, noting the equivalence of the two orthogonal motions, one effected by gravity and the other prescribed by the experimenter. We present an analytical solution using Newtonian mechanics to confirm Leonardo’s “Equivalence principle”.