Hedy Lamarr

Hedy Lamarr

Hedy Lamarr (1914-2000) was an Austrian-American film actress and inventor. As far as we know, she is the only person to get a star on the Hollywood Walk of Fame and a patent in the field of radio-controlled torpedoes.

In 1941, Lamarr and the composer George Antheil developed a radio guidance system for torpedoes. Using a code stored on a punched paper tape, the system would synchronise random frequencies (“frequency hopping”) between a receiver and a transmitter to decrease the risk of jamming. It is one of the techniques we today call spread-spectrum.

In 1997, Lamarr and Antheil received the Electronic Frontier Foundation Pioneer Award and the Bulbie Gnass Spirit of Achievement Bronze Award. In 2014, they were inducted into the U.S. National Inventors Hall of Fame in 2014.


Hedwig Eva Maria Kiesler was born in Vienna, Austria on November 9, 1914. She was the only child of Gertrud “Trude” Kiesler (born Lichtwitz; 1894–1977) and Emil Kiesler (1880–1935).

Emil had been born into a Galician-Jewish family in Lemberg (now Lviv, Ukraine) and Gertrude was born into an upper-class Hungarian-Jewish family in Budapest. Gertrude had converted to Catholicism and was a practising Christian who raised Hedwig in the Christian faith.

Hedwig Kiesler had a budding acting career in Europe in her teens, but that came to a stop when the 18-year-old Kiesler married the very rich 33-year-old Austrian military arms merchant and munitions manufacturer Friedrich Mandl in Vienna. Her parents did not approve of him, chiefly due to this ties to Benito Mussolini and Adolf Hitler. (Interestingly, Mandl himself was the son of a Jewish father and a Catholic mother.)

In her autobiography, Lamarr would later describe her husband as extremely controlling. 1937, she left him and fled abroad to resume her acting career. After meeting the Metro-Goldwyn-Mayer studio head Louis B. Mayer in London, she was offered a movie contract and migrated to the United States in 1938. There, she became known under the name Hedy Lamarr. The surname Lamarr was suggested by

Mayer´s wife, who admired the beautiful silent film star Barbara La Marr.

Radio-guided torpedoes

Lamarr had no formal scientific or technical training and was chiefly self-taught. She liked to tinker with inventions as a hobby, and did for instance work on making a traffic spotlight.

When World War II broke out, she was living in the United States and her career in Hollywood was going well.

Her interest in radio-guidance was piqued when she learned that radio-controlled torpedoes had been proposed, but that the enemy might be able to jam a radio-based guidance system and set the torpedo off course.

When discussing the issue with her friend, the pianist George Antheil, they came up with the idea of using a frequency hopping signal to prevent the enemy from tracking and jamming the torpedo´s radio guidance system.

Antheil synchronized a miniaturized player piano mechanism with radio signals, and then sketched-out the basics of a system that would use a perforated paper tape to actuate pneumatic controls – as in player pianos.

For a year, Lamarr employed Samuel Stuard Mackeown, a professor of radio-electrical engineering at Caltech, to develop the functionality of the idea. She also hired the law firm Lyon & Lyon to search for prior knowledge and craft a patent application.


US Patent 2,292,387 was granted on August 11, 1942 to Hedy Kiesler Markey and George Antheil. (She had been married to Gene Markey in 1939-1941 used her married name for the application.)

Was it used?

Not during World War II, because the US Navy was not using radio-controlled torpedoes at the time, and electro-mechanical devices of this type were soon rendered obsolete by purely electronic solutions.

With that said, the US Navy did adopt frequency jamming technology in the 1960s and the principles of Lamarr´s and Antheil´s work are incorporated into Bluetooth and GPS technology. There are also similarities between that technology and certain methods used in legacy version of CDMA and Wi-Fi.

Film career

Lamarr´s early acting career Europe included the controversial 1933 movie Ecstasy.

After meeting the Metro-Goldwyn-Mayer studio head Louis B. Mayer in London, she was offered a movie contract and migrated to the United States, where her performance in the 1939 film Algiers was well received.

Examples of MGM films with Hedy Lamarr are Lady of the Tropics (1939), Boom Town (1940), H.M. Pulham, Esq. (1941), and White Cargo (1942).

In 1949, Lamarr starred as Delilah in the much praised Samson and Delilah, directed by Cecil B. DeMille and released by Paramount Pictures.

Her final film was The Female Animal (1958) and she was honoured with a star on the Hollywood Walk of Fame in 1960.