"Oh ye seekers after perpetual motion, how many vain chimeras have you pursued? Go and take your place with the alchemists." — Leonardo da Vinci, 1494 Perpetual motion is the motion of bodies that continues forever in an unperturbed system. A perpetual motion machine is a hypothetical machine that can do work infinitely without an external energy source. This kind of machine is impossible, as it would violate either the first or second law of thermodynamics or both. Luckily for us, we're...