Sundog Skypools
By Jonathan Shock (photostream).
©Jonathan Shock, shown with permission

An English lake reflects and weaves a sky borne sundog into ever changing whorls, loops and pools of colour - skypools.

Order in the sky has transformed to a different
order of an aquatic kind.

In high and cold clouds, hexagonal ice crystals improbably aligned to float near horizontal and of uncanny geometric plus optical perfection make sundogs possible.

Water has its own optical perfection and order, microscopically it is far beyond that of the sundog's crystals.  How often do we wonder why water's surface is smooth and when vibration free mirrors light more precisely than the best crafted optics? Why is it not rough or wrinkled or fuzzy like cloud edges? Water's molecules jostle and attract. To keep a thermodynamic balance between energy, temperature and disorder its surface is forced incredibly flat - or more precisely, sculpted to Earth's curve - until, that is, temperature and disorder abruptly win over energy and it boils.

The English lake water has another order on a larger scale.  Wind and perhaps confinement at its shores can, when just so, induce its surface to oscillate in alternating hollows and rises.  Still water's perfect plane mirror is replaced by one that, even when time frozen by cameras, has curvature changing continuously from place to place.  Concavities of hollows grade smoothly to convex peaks.    These mirrors are the stuff of skypools.  There is no simple single reflective replication of the scene.  Instead, each element of sky and lake shore gets spun into multiple concentric ovals, sky then shore then sky and shore again.. ..and again.

Set time free and the pools and rings quickly change and move, so quickly that they can escape notice. And often they show only in small patches. Like so many of the best optical sights, they must be sought to be treasured.

About - Submit Optics Picture of the Day Galleries Previous Next Today Subscribe to Features on RSS Feed