William Gurstelle has been writing for Make: magazine pretty much since the beginning. Besides 40 or so “ReMaking History” columns, his work there has included do-it-yourself pieces on a gravity-powered catapult, a taffy-pulling machine, a Taser-powered potato cannon, and an ornithopter. He’s also a bestselling author, a registered engineer, and a popular speaker on the world of science and technology.