As we know from Genesis, God is “famously keen on maintaining boundaries between domains”, says Charles Foster in Literary Review. “He separated the light from the darkness,” we are told, “and called the light ‘day’, and the darkness ‘night’.” But that’s something we humans have been undoing: in much of the world, lights are so ubiquitous that night has effectively been cancelled. The night sky in Hong Kong shines 1,200 times more brightly than if it were unilluminated. Millions will “never see the constellations” central to the stories humans tell about the cosmos. The “gentle” hubris of firelight has been supplanted by engineers planning to put artificial moons in space, pumping out light eight times stronger than the real thing.
Light pollution is a “dangerously under-recognised horseman” of the environmental apocalypse. One third of all vertebrate species and nearly two thirds of invertebrates are nocturnal: “mess with the night” and you jeopardise their existence. We’re also destroying our own biological clocks, built around a cycle of night and day that began 4.5 billion years ago. Part of our obsession with banishing the dark is “atavism” – the fear that if the lights go off, we’ll once again “be at the mercy of the sabre-toothed tigers”. But I think we’re also scared of what true darkness “will show us of ourselves”. For the sake of our environment, we must challenge our dependence on artificiality. “Let us take back the night,” as the author Johan Eklöf puts it. “Carpe noctem.”