Balance rules us all. Our bodies need both light and darkness to keep natural processes humming along properly — including our vision and sleep. And while we may instinctively fear the dark, perpetual light can be just as frightening. Were we transported to a planet with three suns and no darkness, we’d look nice and tan. We'd also most likely spiral into madness, because darkness is essential to good rest. The brutality of sleep deprivation is a worse threat than anything that might be lurking in dark corners.
For those living within 50 miles of the Arctic Circle, an existence assaulted by constant light isn’t hypothetical. In parts of Russia and Iceland, the sun only sets for five or six short hours in the summertime. In the Norwegian town of Nordkapp, the sun shines for 1,800 hours, or 75 days, before setting. In the northernmost parts of Finland, Norway and Alaska, the world is bright and alive for weeks on end. Perpetual daylight allows for fun and excitement — especially after the drab winter — but it also robs people of their sense of time and normal cycles, and, oftentimes, makes sleep a struggle.
Darkness is as powerful a cue for sleep as light is. The suprachiasmatic nucleus, the brain structure that controls the sleep-and-wakefulness-regulating circadian rhythm, is housed at the intersection of our optic nerves. When light floods our eyes and optic nerves, processes are signalled and we start to wake up; when light wanes and darkness approaches, our brains are prompted to produce the sleep-inducing hormone melatonin. Without darkness, the signal doesn’t get transmitted.
“Melatonin signals that it’s dark and it’s time to sleep,” says Abel Bult-Ito, a professor of neurobiology in the Department of Biology and Wildlife at the University of Alaska in Fairbanks. “Generally the melatonin starts to rise one to two hours before people start to sleep.”
This system, Bult-Ito says, presents a unique problem in the [Arctic] summer. “People are exposed to light during what normally should be the dark period or the nocturnal period, especially at the end of the day or at night.”
The midnight sun follows the polar night, a protracted period of darkness where, in extreme northern areas, the sun doesn't rise at all between November and January. Several people interviewed for this story described the long darkness of polar night as depressing.
Jason King, a 25-year-old active duty service member of the Air Force, has been stationed in Eielson Air Force Base, near Fairbanks, Alaska for just over two years. He said there’s little to do in the winter other than sit by his computer.
“By January I start to get a little stir crazy,” King said. “When the summer finally hits, I just want to be outside as much as I can.”
That makes sense: Seasonal Affective Disorder kicks in during standard-fare winter for many people, leaving them with sapped energy and emotional distress. Sleep doctors often recommend a light box to patients with such symptoms, as grey, wintry skies have left them without regulatory signals and vitamins. There is no real solution, however, for too much sunlight. There is no darkness machine.
While we’d like to think otherwise, humans are creatures of routine. Without the natural order of things, we slowly unravel. Just consider Al Pacino’s harried, sleep-deprived detective in Christopher Nolan’s “Insomnia.” He chases a criminal to the deepest parts of Alaska, where perpetual sunlight (along with some personal issues) holds his sleep hostage. Rather quickly, he begins to go crazy.
“It’s a bit maddening,” said Grant, a 32-yeard old accountant who grew up in Anchorage and spent many summers in the most remote parts of Alaska. “The dark and cold force you to stay inside and lose your mind a bit; the extreme daylight is a different beast: It’s beautiful and you want to stay outside and enjoy it longer, especially because of the winter you just endured, but then you quickly lose track of the day and find yourself having trouble sleeping.”
Surprisingly, not all folks living in 24-hour darkness experience depression. Psychological studies on Tromsø, Norway, situated 200 miles from the Arctic circle, found remarkably low rates of depression among the island town's 70,000 residents, despite them living under a month-long blanket of darkness.
One thing is for certain: The lack of darkness screws with your sense of time. A source who worked a temporary job in Alaska told us that while she fell asleep fine, she would jolt awake up at 3am, panicked about sleeping through her morning shift.
King experienced a similar time confusion. “My first summer I was camping and fishing, and planned to go to bed around midnight so I didn't waste my whole Saturday sleeping,” King said. “It felt like I blinked, looked at my phone and it was almost 5am.”
There are precautions to take. Alaskan residents say that in summer, bedroom windows become shabby, multi-textural monuments to the human need for darkness. To block out light, many cover windows with blackout shades, bed sheets or whatever fabric they have on hand. Others tape tinfoil to the glass, covering the blank spaces that curtains don't reach. Sleep masks, too, are a common defense.
Eyemasks and tinfoiled windows are a means of adapting to a way of life. But does it always have to be that way?
There’s evidence that animals — and possibly people — can adapt their circadian rhythms to the extreme light and dark of the arctic winter. Bult-Ito has studied the circadian rhythms of mice and voles, a species of Alaskan rodent. In his research, he noticed that mice and vole strains with weaker circadian rhythms found it easier to shift their clocks in response to light pulse. He also saw that voles, whose lifespans average three to six months, would adapt their circadian rhythms within two or three generations.
Given his research, Bult-Ito believes it’s possible that animals and people could evolve to develop an elastic circadian rhythm that responds to the extreme light and darkness of the Arctic Circle.
“My hypothesis for humans is that people who have lived in the arctic for many generations, such as the Alaskan native peoples, would have rhythms that are easily shifted to keep up with the large day length changes in the north,” he said.
Only time will tell. As for Bult-Ito, himself a Netherlands native, shifting his circadian rhythm wasn’t as easy. Sleeping during the polar night and midnight sun took a long period of trial and error. After living in Fairbanks for 17 years, he’s finally settled into a seasonal routine.
What’s his secret?
“I tried to block out the light in the bedroom with sheets and stuff but I realized it was a lot easier and cheaper to just put an eye mask on,” he said.
It'll have to do. That is, until evolution changes the game.