MGM billed her as “the world’s most beautiful woman” but her brain was just as beautiful. Hedwig Kiesler, a Viennese Jew, took the name Hedy Lamarr in Hollywood, where she made her mark as an actress in the 1930s. Lamarr did something deeper in the 1940s: she invented—and patented—a radio guidance system meant to make Allied torpedos undetectable, an idea that would point the way to Bluetooth technology. Lamarr never returned to Vienna during her life, but she is buried there. This exhibition honors a prodigal daughter. —L.J.