The cozy little village of Rjukan, Norway, is a delightful place to live—except during the dark days of winter. Located in a valley at the foot of the towering Gaustatoppen Mountain, the town receives no direct sunlight for nearly half of the year. Residents had long considered the idea of placing mirrors at the top of the mountain to reflect the sun. But the concept was not feasible until recently. In 2005, a local artist began “The Mirror Project” to bring together people who could turn the idea into reality. Eight years later, in October 2013, the mirrors went into…