October 23, 2013 Rjukan's 3,500 residents, tucked in a shadowed valley, have finally realized the dream of one of the town's founders: giant mirrors to focus the warmth of the sun.
September 11, 2013 We know a lot. But we don't know everything. In fact, science still has quite a few "big" questions left to answer. Physicist Marcelo Gleiser pokes at 10 of them, questions highlighted in a new book naming the most difficult scientific problems of our time.
May 5, 2013 The Solar Impulse, an airplane traveling across the United States using only solar power, is in Phoenix today, after reaching Arizona from California Saturday. It took the plane about 20 hours to travel from Mountain View, Calif., near San Francisco.
March 27, 2013 Creators of a solar-powered aircraft hope to fly it day and night across the U.S. with no fuel, and eventually around the world. It's a quixotic — some might call it nutty — undertaking. But the creators hope the flight helps challenge assumptions about what solar technology can do.