There are few things more beautiful in their simplicity than the rebounding columns of water that result from droplets hitting a larger body of liquid. It’s something we’ve all seen, time and time again, from raindrops to leaky sinks. With the advent of modern technology, we are able to see beyond normal time, and capture these transient moments on a scale of time and space without which we could not appreciate their brilliance.
How this beauty works: That particular shape, the droplets that rise up when another droplet strikes the pool, is called a “backjet”. The force of a falling droplet divides the liquid it falls into, creating a void and exerting pressure on the liquid around it. The molecules of water rush back together at high velocity, driven by surface tension and reacting to the pressure exerted by the displaced liquid. When that tiny hole snaps back together, the force drives excess water upward, creating the beautiful “backjet” you see here.
Along the edge of the flat, mushroom-like cap, tiny sub-droplets are breaking off in an almost fractal manner, each driven to division by an outward force that pinches them off and overpowers the surface tension.
See more of Markus Reugels’ stunning droplet photography at Colossal.