Engineering Hall of Fame

Hedy Lamarr
9 November 1913 – 19 January 2000

by Mary Ann Hoffman and Michael N. Geselowitz

March is Women’s History Month, making it an appropriate time give some attention to women’s contributions to engineering. In fact, this year’s theme, Women Pioneering the Future, makes such attention even more appropriate than usual. In honor of Women’s History Month, the IEEE History Center is featuring several pioneering engineering women on its web pages. In this column, we thought we’d share the fascinating story of a woman who achieved her greater fame outside of technology: Hollywood actress, Hedy Lamarr.

Hedy Lamarr was a remarkable combination of movie star and inventor. Born in Vienna, Austria in 1913 as Hedwig Eva Maria Kiesler, she achieved fame in 1933 as the star of the scandalous Czech film Extase, which featured perhaps the first nude scene in cinematic history. That same year, Lamarr married fellow Austrian Fritz Mandl, a leading European armament manufacturer. Mandl specialized in shells and grenades, but beginning in the mid-1930s, he also manufactured military aircraft.

Mandl was interested in control systems and conducted extensive research in the field. With his young wife by his side, he attended hundreds of dinners and meetings with arms developers, builders and buyers. Clearly, Lamarr learned some things at these events. The marriage broke up in 1937, when Lamarr, an anti-Nazi of Jewish descent, escaped to London. MGM soon signed her and she moved to Hollywood, where she starred in several successful films, including 1949’s Samson and Delilah.

In 1940, Lamarr befriended avant-garde composer George Antheil, who wrote and played pieces with such names as Airplane Sonata and Ballet Mécanique, the latter featuring mechanized instruments of his own invention. Scarcely a year later, the pair applied for a patent on a device that would reduce the danger of detection or jamming for radio-controlled torpedoes. Although the idea of radio control for torpedoes was not new, the concept of frequency hopping was. Frequency hopping means broadcasting a signal over a seemingly random series of radio frequencies, switching from frequency to frequency at split-second intervals. Anyone trying to eavesdrop would hear only random noise, like a radio dial being spun. If both the sender and the receiver were hopping in sync, however, the message would go through loud and clear. Apparently, Lamarr had brought up the idea of unjammable radio control, while Antheil suggested a device by which could achieve synchronization. On 11 August 1942, they obtained their patent on a Secret Communication System.

Although the Navy shunned the device at the time, by 1957 engineers at Sylvania Electronic Systems began developing the concept. In 1962, three years after the original patent expired, the Nave used the pair’s idea in military communication systems installed on U.S. ships sent to blockade Cuba. Subsequent patents in frequency changing have referred to the Lamarr-Antheil patent as the basis of the field. And Lamarr and Antheil’s concept lies behind the principal anti-jamming devices used today for such applications as the U.S. government’s Milstar defense communications satellite system.

Neither Lamarr nor Antheil ever received royalty payments for the commercialization of their patent. Moreover, their invention was only formally acknowledged by the Electronic Frontier Foundation (EFF) in March 1997 — somewhat belatedly for Antheil, who died in 1959. Lamarr’s son, Anthony Loder, received the EFF award on behalf of his mother, then an 83-year-old Florida retiree. She died three years later, on 19 January 2000.

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Mary Ann Hoffman is Manager of Archival & Web Services at the IEEE History Center at Rutgers University in New Brunswick, N.J.

Michael N. Geselowitz, Ph.D., is director of the IEEE History Center at Rutgers University in New Brunswick, N.J. Visit the IEEE History Center's Web page at: www.ieee.org/organizations/history_center/