Unlike here in New York, where telling a cabbie to take you to even some of the most common intersections often result in a response of "Okay, how do I get there?", London cabdriver tests are notoriously difficult and complete. You don't just pass the test--you earn "The Knowledge," or the ins and outs of a massive and complex city from end to end. And, it turns out, the level of training needed to pass the test actually changes the structure of the brain, according to a new study.
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.