Another image from the day-one slide show I couldn't let get buried: James Nick Sears and his dad's amazing "persistence of vision" project, called the ORB. The ORB is hundreds of computer-controlled LEDs soldered into a ring that spins at an impressive 1,600 rpm. A computer synchronizes the LEDs to project animated digital images in full 3-D. —John Mahoney
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.