In A Nutshell
Rjukan is a small village in Norway near the lower rim of the Arctic Circle. For six months each year, the town is bathed in darkness, too deep in the mountains to get any natural sunlight. So they created their own—by placing massive mirrors around the mountain ridges to reflect sunlight into the village.
The Whole Bushel
With a population of barely over 3,000 people and an inhospitable—though scenic—locale in the shadow of Norway’s tallest mountain, Rjukan could well be defined as a patch of humanity in the middle of nowhere. Built as an industrial checkpoint by the Norsk Hydro company in the early 1900s, the cost of bringing supplies and building materials into the valley was nearly twice as much as Norway’s national budget. Remote and isolated, Rjukan was barely more than an outpost for factory workers and their families until 1996, when the municipality upgraded Rjukan’s designation to “town.”
And there’s another problem that plagues the residents of Rjukan—from mid-September until early March, there is no sunlight.
At the extreme poles of the Earth, it’s not uncommon to have drastically lengthened days in the summer and near-total darkness during winter for weeks or months on end due to the way the Earth rotates in relation to the Sun. Norway lies about half in and half out of the Arctic Circle, and their summer period has given the country the name “Land of the Midnight Sun”—from May to July, the sun never completely dips below the horizon. However, that’s only in the northern regions, inside the Arctic Circle. The south of Norway has some reprieve from the endless daylight, though the sun can still shine for at least 20 hours a day.
Of course, constant daylight in the summer means the opposite is true for the winter, and the northern latitudes of Norway are plunged into darkness for around three months at the height of winter. Rjukan is well below the rim of the Arctic Circle, but they seriously got the short end of the stick in the daylight department—the town is completely surrounded by mountains, so even though other villages near them get the benefit of a sunrise, Rjukan just gets six long months of night. The effect is like holding a flashlight level with the outer rim of a bucket—it’s still shining, but anything inside the bucket is in perpetual shadow.
Deciding they’d had enough, the residents of Rjukan put into motion a project that would have made Wile E. Coyote proud—they erected three massive mirrors along the mountain ridge to reflect the Sun’s rays into the town square. The mirrors hang 450 meters (1,500 ft) over the town and rotate with the Sun’s trajectory to keep the sunbeam smack dab in the center of the town square the entire day. It cost 5 million kroner, or about $849,000, to build the device and airlift it to the top of the mountain. The resulting patch of light is 600 square meters (6,500 sq ft), and for the first time in 100 years, Rjukanians can feel the sun on their skin all year round.
Show Me The Proof
BBC: Mirrors finally bring winter sun to Rjukan in Norway
The Polar Night, Chris Burn