Leonardo

Leonardo wrote:

"A fall of water strikes the water below and produces three motions: the first is that which, having struck the standing water, dives into it, and this has five branches, because the water which is divided in the dive is divided into five parts; of which the middle one plunges to the bottom, and the four lateral ones turn upward, curling in various directions.

The second movement is the rebound of the air which plunges down with the water and returns to the surface, breaking through the wave that covers it, and throwing into the air spray and droplets; and then it expands over the surrounding water in the form of bubbles.

The third movement is that of the wave generated by the impact, which spreads outwards in circles that gradually widen until they spend themselves against the banks, or die away into smoothness."

In his extended notes on this observation, Leonardo goes on to catalog fourteen distinct micro-actions occurring simultaneously—including the friction between falling air and water, the sub-surface cavitation, the formation and bursting of bubbles, and the counter-rotating lateral vortices.

As his biographer Walter Isaacson says, “Try noticing all that when you next fill a sink.”  Genius is incomprehensible.