Subscribe to ITN News: http://bit.ly/itnytsub Giant mirrors have been positioned on top of a hill in Norway to shine light into the dark valley town of Rjukan. The sides of the valley are so steep and the mountain so high that the town of Rjukan was in shadow for almost half the year until the new invention was added. The mirrors are controlled by a computer that follows the path of the sun, adjusting to the best angle to catch the rays and reflect them onto the town centre. Report by Sarah Joh