More than 100 years ago scientists and business leaders feuded over the incipient U.S. electrical grid: Should it rely on alternating current (AC) or direct current (DC)? Both are used to transmit electricity—DC flows steadily in one direction, whereas AC varies direction periodically. Thomas Edison championed DC as the better option—and even publicly electrocuted stray animals with AC to convince the public that it posed a danger. By the early 20th century AC prevailed, however,