There is a single belief so old and so widespread that it appears in nearly every culture humanity has ever produced, in societies that never met and never shared a word. The conviction that a look can harm you. The evil eye. The idea that a glance, especially one born of envy, can carry something across the air and into the person it lands on, souring their luck, sickening their child, cracking their fortune. Not a spoken curse. Just a look, covetous and lingering, from some

In the 1780s, in a laboratory in Bologna, a man named Luigi Galvani was dissecting a dead frog when his assistant’s metal scalpel touched an exposed nerve at the same moment a spark jumped from a nearby electrical machine. The dead frog’s leg kicked. Galvani froze. The animal was dead. He had killed it himself. And yet the leg had moved, as if for one instant the spark had reached down into dead tissue and called it briefly back to life. He hung frog legs on brass hooks from