page_title: Hedy Lamarr
section_title: Frequency-hopping spread spectrum
hierarchical_section_title: Hedy Lamarr / Inventor / Frequency-hopping spread spectrum
caption_attribution_description: English: Patent for Secret Communication System
context_page_description: Hedy Lamarr, born Hedwig Eva Maria Kiesler, was an Austrian-American actress, inventor, and film producer. She was part of 30 films in an acting career spanning 28 years, and co-invented an early version of frequency-hopping spread spectrum.
  Lamarr was born in Vienna, Austria-Hungary, and acted in a number of Austrian, German, and Czech films in her brief early film career, including the controversial Ecstasy. In 1937, she fled from her husband, a wealthy Austrian ammunition manufacturer, secretly moving to Paris and then onward to London. There she met Louis B. Mayer, head of Metro-Goldwyn-Mayer studio, who offered her a movie contract in Hollywood, where he began promoting her as "the world's most beautiful woman".
  She became a star with her performance in Algiers, her first film made in the United States. She starred opposite Clark Gable in Boom Town and Comrade X, and Jimmy Stewart in Come Live with Me and Ziegfeld Girl. Her other MGM films include Lady of the Tropics, H.M. Pulham, Esq., as well as Crossroads and White Cargo; she was also borrowed by Warner Bros. for The Conspirators, and by RKO for Experiment Perilous.
context_section_description: During World War II, Lamarr learned that radio-controlled torpedoes, an emerging technology in naval war, could easily be jammed and set off course. She thought of creating a frequency-hopping signal that could not be tracked or jammed. She conceived an idea and contacted her friend, composer and pianist George Antheil, to help her implement it. Together they developed a device for doing that, when he succeeded by synchronizing a miniaturized player-piano mechanism with radio signals. They drafted designs for the frequency-hopping system, which they patented. Antheil recalled:
  We began talking about the war, which, in the late summer of 1940, was looking most extremely black. Hedy said that she did not feel very comfortable, sitting there in Hollywood and making lots of money when things were in such a state. She said that she knew a good deal about munitions and various secret weapons ... and that she was thinking seriously of quitting MGM and going to Washington, D.C., to offer her services to the newly established National Inventors Council.
  Their invention was granted a patent under US Patent 2,292,387 on August 11, 1942 (filed using her married name Hedy Kiesler Markey). However, it was technologically difficult to implement, and at the time the US Navy was not receptive to considering inventions coming from outside the military. Nevertheless, it was classified in the "red hot" category. It was first adapted in 1957 to develop a sonobuoy before the expiration of the patent, although this was denied by the Navy. At the time of the Cuban Missile Crisis in 1962, an updated version of their design was installed on Navy ships. Today, various spread-spectrum techniques are incorporated into Bluetooth technology and are similar to methods used in legacy versions of Wi-Fi. Lamarr and Antheil's contributions were formally recognized in the late twentieth and early twenty-first centuries.
caption: Copy of U.S. patent for "Secret Communication System"
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