Hedy Lamarr, inventor

Hedy Lamarr was born 101 years ago today, on November 9, 1914.  While film buffs know Lamarr, born as Hedwig Eva Maria Kiesler, for her roles in many classic films (you can see her filmography at IMDB and the official Hedy Lamarr site), she was also an accomplished inventor.

Hedy Lamarr’s inventions

Lamarr is best known for a patent application on which she is the first inventor (as Hedy Kiesler Markey), with George Antheil as her co-inventor, is US Patent 2,292,387, issued Aug. 11, 1942, for a “Secret Communication System.”  (You can view a PDF of the patent at the USPTO’s site, though the viewer does not always work; Google has the patent images and OCR of the patent’s text available).  The subject of the patent is an implementation of frequency-hopping spread-spectrum technology intended for a difficult-to-jam radio-frequency guidance system for torpedoes.  The invention worked by continually and unpredictably changing the radio frequencies used for control signals transmitted to a torpedo, which would prevent the signal being jammed by transmissions from enemy ships.  By transmitting on multiple radio frequencies, and switching frequencies rapidly (multiple times per second), the radio signals would sound like random noise to anyone monitoring any of the frequencies. But, with the sender and the receiver of the signal hopping frequencies simultaneously, the signal would be clear.  The invention could also be used for other communication, to prevent sensitive messages from being intercepted.

The U.S. Navy was not interested in using the spread-spectrum technology at the time.  Antheil was a composer of avant-garde music, among other pursuits, and the Lamarr-Antheil invention used a device inspired by the roll mechanism in a player piano.  Antheil was later quoted as having said that comparing the mechanism of their invention to a player piano when pitching it to naval officers was probably a bad idea.

“‘My god,’ I can see them saying, ‘we shall put a player piano in a torpedo.’”

Later use of spread-spectrum

But, the Navy did use an updated version of the Lamarr-Antheil invention during the Cuban Missile Crisis in 1962 (after the patent expired).  And more recently, spread-spectrum technology has been crucial to digital communications, making cellular phones and other wireless communications possible.  The Lamarr-Antheil patent has been cited by US patent applications 83 times, as of today.

Other Lamarr inventions

Hedy Lamarr also invented an improved stoplight, and a pill that when dissolved in water created a soda – though according to a biographer, she reportedly said it didn’t taste good.  Well, they can’t all be ground-breaking technological leaps that enable a generation of communication!

Recognition for Lamarr

Hedy Lamarr received the Electronic Frontier Foundation’s Pioneer Award, for her co-invention of spread-spectrum broadcasting, in 1997.  She was inducted into the National Inventors Hall of Fame in 2014, as was George Antheil.  And today, Google honored Hedy Lamarr with a Doodle celebrating her life and work, both as an inventor and actor.