Ripples: the one shape water draws on its own

Water has no interest in shapes, except this one. A drop falls, and a circle starts moving outward at a speed that never changes its mind. The strange part is that the circle keeps its geometry while losing its conviction, wider and fainter with every second, until the surface goes back to pretending nothing happened.

What the rings actually do is take the reflection apart. The bank, the trees, the one cloud that was sitting there whole a moment ago get cut into strips and shuffled, then reassembled in the order they came from. Shutter speed decides which version you keep: fast enough and you count the rings, slow enough and every circle smears into a soft grey that looks like weather rather than water.

On a screen the ripple is unusually polite. It gives you a centre without putting anything in it, so icons sit between the rings instead of on top of a subject. It is also one of the few still images that a person half believes is about to move, which is a good thing to have open behind everything else you are doing.