I enjoyed these passages in A. Roger Ekirch’s At Day’s Close: Night in Times Past, a well-known and well-liked work of social history, where he describes how the term “nightfall” reveals an older way of thinking about night. Not as the absence of light, but as an actual substance descending from the sky. As he points out, “falling” is not in fact an accurate visual description of what happens at sundown:

Rather than falling, night, to the watchful eye, rises. Emerging first in the valleys, shadows slowly ascend sloping hillsides. Fading rays known as “sunsuckers” dart upward behind clouds as if being inhaled for another day. While pastures and woodlands are lost to gloom, the western sky remains aglow even as the sun draws low beneath the horizon. …

Darkness signified more than the temporary absence of light. According to popular cosmology, night actually fell each evening with the descent of noxious vapors from the sky. Night, wrote Richard Niccols in 1610, “did powre grim darknesse downe.” Kept at bay by daylight, descending mists reportedly contributed, no less than the sun’s departure, to the onset of darkness. In Herefordshire, nightfall was known as “drop night.” Some individuals described themselves “within night,” as if enveloped by a mammoth black cloud; in fact, criminal prosecutions in Scottish courts routinely referred to offenses having been committed “under cloud of night.” …

In his essay “On Nightfall, What It Is, and Whether It Falls on Us,” the sixteenth-century French physician Laurent Joubert derided popular fears… he disputed the prevailing notion that “nightfall is a certain rheumatic quality in the evening and night air that falls from the sky.” “There is no evil quality in nightfall air,” he insisted, with night itself being “nothing more than the obscurity or darkness of the air as a result of the absence of the sun.” All the same, the traditional wisdom about nightfall persisted for many years.

The idea of sixteenth-century pamphleteers duking it out over the reality of nightfall, in a sort of archaic version of internet flame wars over climate change, is somehow very pleasing.