Sundial Solargraph

Sundials are exquisite. Quietly and with no moving parts, a shadow and a line give excellent time. Solargraphs are brute force archives of the sun's presence in our lives. The 2022 sundial solargraph shows the "shark fin" of a sundial silhouetted in the foreground of the rising solar arcs.

Solargraph with sundial in foreground, above, paired with panorama of same sundial.

A panorama featuring the same sundial sets the scene. The pinhole of the solargraph can is level with the base of the sundial. While the gnomon (the leading edge of the "shark fin") is machined straight and points toward the north celestial pole, the edge appears slightly curved. Despite the wide-field distortion, every arc of the sun intersects the gnomon at a right angle.

Left of the "shark fin" is a short but straight power pole. Right of center is a black walnut tree with a well defined trunk. It's branches appear differently in the pair of images. The panorama suggests the tree has drooping leafy branches, while the solargraph shows an inverted trident of scrawny branches. And in those lower winter arcs, the sun seems bright.

When the sun is reaching summer heights, the dense leaves block much of the sunlight from reaching the pinhole, despite the longer days defined by longer arcs. Months later, the lower branches have lost their leaves when the sun is seasonally low. The unimpeded sunlight passes through the pinhole and strikes the black-and-white photographic paper inside the can.

The December 2022 solstice coincided with the onslaught of a historic winter storm, so the can remained in place several extra days.