When scientists struggle to explain the weird implications of quantum mechanics, in which electrons can spin simultaneously clockwise and counterclockwise or dart here and there at the same time, they often fall back on a scenario concocted more than a half-century ago by the physicist Erwin Schrodinger.
Put a cat in a box, he proposed, and rig up a Rube Goldberg contraption involving a hammer, a vial of poison and a quantum triggering device. If an electron is in one position, the hammer will remain safely cocked. But if the electron moves into the opposite location, the hammer will drop, smashing...