About 13,000 years ago, a chunk of a comet or asteroid hurtled into the atmosphere at a shallow angle, superheating the atmosphere around it as it careened toward the surface. The air grew hot enough to ignite plant material and melt rock below the object’s flight path. Within a few microseconds, atmospheric oxygen was consumed and the freed carbon atoms condensed into nanodiamond crystals.
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.