Frequency-Hopping System 

Hedy Lamarr 

Although Hedy Lamarr was widely celebrated for her acting career, her technological achievements were not fully recognized until decades later. The frequency-hopping system she co-developed with George Antheil became foundational to later spread spectrum communications technology.

Modern wireless systems such as Bluetooth, Wi-Fi, GPS, and some secure military communication systems use principles related to spread spectrum transmission. In 1997, Lamarr received the Electronic Frontier Foundation Pioneer Award, helping bring renewed attention to her role as an inventor. Lamarr had no formal training and was primarily self-taught, she invested her spare time, including on set between takes, in designing and drafting inventions,[50] which included an improved traffic stoplight and a tablet that would dissolve in water to create a flavored carbonated drink.[40]

During the late 1930s, Lamarr attended arms deals with her then-husband, arms dealer Fritz Mandl, "possibly to improve his chances of making a sale".[51] From the meetings, she learned that navies needed "a way to guide a torpedo as it raced through the water." Radio control had been proposed. However, an enemy might be able to jam such a torpedo's guidance system and set it off course.[52]

When later discussing this with a new friend, composer and pianist George Antheil, her idea to prevent jamming by frequency hopping met Antheil's previous work in music. In that earlier work, Antheil attempted synchronizing note-hopping in the avant-garde piece written as a score for the film Ballet Mécanique (1923–24) that involved multiple synchronized player pianos. Antheil's idea in the piece was to synchronize the start time of four player pianos with matching player piano rolls, so the pianos would play in time with one another. Together, they realized that radio frequencies could be changed similarly, using the same kind of mechanism, but miniaturized.[9][51]

Based on the strength of the initial submission of their ideas to the National Inventors Council (NIC) in late December 1940, in early 1941 the NIC introduced Antheil to Samuel Stuart Mackeown, professor of Electrical Engineering at Caltech, to consult on the electrical systems.[53][50] Lamarr hired the legal firm of Lyon & Lyon to draft the application for the patent[54][55] which was granted as U.S. patent 2,292,387 on August 11, 1942, under her legal name Hedy Kiesler Markey.[56] The invention was proposed to the Navy, who rejected it on the basis that it would be too large to fit in a torpedo,[57] and Lamarr and Antheil, shunned by the Navy, pursued their invention no further. It was suggested that Lamarr invest her time and attention to selling war bonds since she was a celebrity