As unlikely as it sounds, newspaper editor Linton Hopkins, Jr. proposed using a portable traffic overpass to de-congest busy street intersections. Theoretically, it doesn't sound like a bad idea: traffic could move uninterrupted in both directions, and drivers would rejoice at never having to stop at a red light. Moreover, the bridge could be taken apart and installed where needed, for far less than the cost required by a permanent structure.
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.