Puddles: The City Printed Upside Down

A puddle does not need depth to work as a mirror. Two or three millimetres of standing water on asphalt gives a surface flat enough to reflect, and the dark road underneath acts like the black backing behind glass, so almost nothing from below competes with the image. That is why the same rain that makes a pale concrete plaza look merely wet turns a black street into a sheet of signs and windows.

Angle does most of the rest. Water reflects only about two percent of the light that meets it head-on, but as the line of sight drops toward the surface the share climbs steeply, past half at grazing angles. People who come home with good puddle shots tend to crouch with the lens a hand's width above the ground, where a puddle the size of a doormat can hold an entire tower. Stand up and the same puddle goes back to showing grey sky and grit.

The reflection is also rarely still. A passing car, a drop from an awning or a breath of wind breaks the neon into bands, and it takes a second or two to settle again. Frames caught in that calm interval make good wallpapers for a reason that is easy to miss: the upper half is busy and the lower half repeats it darker and softer, so icons along the bottom of the screen sit on a quieter copy of the city.