Atmospheric Optical Phenomena

Along the rim of a clear sky, two suns are said to appear side by side where there should be only one. Science explains that the light known as a sun dog (幻日, *genjitsu*) is nothing more than a mirror image conjured by ice crystals high in the atmosphere. Yet in older records, twin suns were feared as omens of catastrophe, and that dread has never quite faded.

An inverted city floating beyond the horizon — the superior mirage distorts a real landscape through layered air and projects it somewhere impossible. The *shiranui* (不知火) is counted among its kin: even now, along the coasts of Kyushu, columns of light are sometimes reported drifting across the sea on summer nights. Fishermen have passed the story down across centuries.

In the Brocken spectre, one's own shadow is cast enormous upon the fog, ringed by a vast halo of light. The figure, known as the "Brocken ghost," has long been spoken of in the same breath as accounts from mountain survivors who swore something was pursuing them through the mist.

In the last moments before dusk, as the sun slips beneath the waterline, a flash of green is said to appear for just an instant. The green flash, they say, may never be seen even once in a lifetime unless every condition aligns — and the sailors of old whispered that it was the final light released by the souls of the dead.

Crepuscular rays — the so-called "Jacob's ladder" — are the shafts of light that seem to pour down from breaks in the clouds toward the earth below. Their counterpart, anticrepuscular rays (反薄明光線, *han-hakumei-kōsen*), appear to converge on the opposite side of the sky, though few ever notice them. No one has confirmed what lies at the point where the light is headed.

Modern science holds that every atmospheric optical phenomenon can be described by the laws of physics. And yet — why do people chase the ends of rainbows, stop in their tracks at the sight of sun dogs, strain their eyes searching the haze for the mirrored city? If what the sky shows us is nothing more than the refraction of light, why does it move something so deep inside us?