Sometimes at night, scientists stare out at the vast universe, and they wonder whats out there. They wonder if its wondering about us. They wonder if whatever's out there is, at that very moment, looking down and marveling at the Great Wall of China or the glimmering lights of our magnificent cities. Or the giant faces of our fast-food mascots.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.