Hedy Lamarr

Hedwig Kiesler was born in Vienna and was acting in films by her late teens. At 19 she married Fritz Mandl, one of the richest arms manufacturers in Austria, who controlled where she went and whom she saw but took her to dinners where military technology was discussed. In 1937 she left him, made her way to London and then to Hollywood, where Louis B. Mayer renamed her Hedy Lamarr and billed her as the most beautiful woman in the world.

She found acting dull and set up an inventing table in her house. When war came she wanted to help defeat the country she had fled. She knew radio-guided torpedoes could be jammed by the enemy. With the composer George Antheil she designed a system in which transmitter and receiver hopped together through a sequence of 88 frequencies, so that a jammer could never find the signal. They were granted a patent in August 1942 and gave it to the US Navy, which filed it away and suggested she sell war bonds instead.

The idea was rediscovered in the 1950s and used on Navy ships during the Cuban missile crisis, after the patent had expired. Frequency hopping became one of the foundations of spread-spectrum radio, which is used in Bluetooth, Wi-Fi and GPS.

She received an award from the Electronic Frontier Foundation in 1997, three years before her death. She said she was glad someone had finally noticed.