BEAUTY and Magnets

摘要

David durlach was a child when he discovered electromagnets. But not until he was in high school did it strike him like a poem that each winding of a wire coil increases the strength of its magnetic field. At that point, he remembers, he started winding electromagnets until his wrists got tired. Once, when a coil grew to the size of an acorn squash and the weight of a bowling ball, he lugged it over to a wall socket and plugged it in. By some miracle the fuses held, but lights throughout the house grew dim. "My parents asked me not to plug it in in the evenings when they were trying to read," he recalls.