Hedy LaMarr: The Movie Star Who Invented Bluetooth… in 1942.
A movie star. An avant-garde composer. A radio-controlled torpedo.
One of the unfortunate truths about our web of modern comforts is that the great majority of them stem, via twisting strands of causality, from warfare. World War II in particular forced the West into an orgy of technological creativity whose fruits we are still blithely and blissfully nomming on. One of the strangest stories to come from that explosion revolves around an invention by screen star Hedy LaMarr, “The Most Beautiful Woman in the World,” of such curiously prescient genius that it forms the core of modern wireless communication theory.
Born in 1914 in Vienna as Hedwig Kiesler, she found her love of acting early, in a city that took its theater as seriously as we take our wet kitten memes. Her early success (including a scandalous nude scene in 1933’s Ecstasy) brought her to the attention of Friedrich Mandl, the third richest man in Austria and a shameless munitions manufacturer who never met a war he couldn’t play both sides of.
Mandl and Hedy married in 1933, when she was only nineteen years old, and he immediately demanded that she give up acting to live in his gilded cage. It was a miserable marriage (one of six for the perpetually unlucky in love LaMarr), but it did have the advantage of exposing her to a steady stream of technical innovators and their revolutionary ideas for harnessing radio to create guided weaponry. Hedy smiled blankly, as she was expected to, and tucked all the knowledge away, bringing it with her when she fled Nazism and her husband at last in 1938.
Aided by Louis Mayer of MGM studios, she was given a new name, Hedy LaMarr (ghoulishly, Mayer just borrowed the surname LaMarr from an actress who had just died and therefore… wasn’t… using it?) and a career in Hollywood. The thing was, though, that in between films LaMarr had little to do. The Hollywood scene bored her, and she was making enough money not to jump at every role offered her.
So, she began inventing, innocuous items at first, those kitchen gadgets that are supposed to make life easier until they take up so much space there is no more room for actual, legitimate food. But with the European war threatening to drag the United States into its grasping maw, LaMarr turned her attention to weapon design, and in particular to the thorny question of torpedo guidance systems.
Sounds pretty random, but it was a hot topic of discussion at Mandl’s dinner parties. It stumped the greatest engineers of Europe, but LaMarr was confident she could solve it. The basic issue was this: traditionally, you fired a torpedo and hoped your target would continue its original straight-path course. If it turned, or if water currents jostled your torpedo, you were just out of luck. What was needed was something that let you send change-of-course instructions to a torpedo while it was underway – “A little left there, pal. Now keep on a-goin’.”
The obvious way to do that was through radio signals, but keeping a guiding channel open made it easy for enemy vessels to simply flood that channel with noise, effectively jamming your ability to guide your torpedo in spite of all your quite fancy radio control systems.
LaMarr’s solution was wonderfully elegant, if such a phrase can be used for, let’s not forget, an instrument of death. She called it Frequency Hopping. What if, instead of using just one frequency, the ship and torpedo could be made to synchronously hop together between multiple frequencies? That way, if the enemy somehow found and jammed one, it would only affect a small part of the ship’s guidance capacity. This idea, of synchronous multi-frequency hopping to avoid interference and enhance connectivity, would become the basic principle of Bluetooth technology six short decades later.
The trick was in practically synchronizing the ship with the torpedo so that both hopped to a new frequency together. Of course, that’s where you seek advice from an avant-garde classical composer. George Antheil was a perpetually broke modernist who peaked in 1926 with the debut of his Ballet Mecanique, a piece originally intended to accompany a Dadaist experimental film (you can see it in its full glory below) and that went on to cause a full-blown riot at its concert premiere. It called for an airplane propeller and sixteen synchronized player pianos to drive forward its ruthless rhythmicality. Listening to it now, you can hear it striving for the ironic angularity of Prokofiev but not quite getting there.
The piece failed dismally in America soon thereafter, and the next two decades saw Antheil scrounging for whatever work he could get – composing film scores, writing absurd articles about how a knowledge of glandular systems can help a gent tell whether a girl is “willing”, and inventing a piano teaching robot called SeeNote.
In 1940, he didn’t have much going for him, but his time wrestling with the logistics of the Ballet Mecanique had taught him a smidge about synchronizing machines, and it was that knowledge he offered LaMarr when they met and began their inventive collaboration.
Their ultimate proposed mechanism was pure simplicity. Both the ship and torpedo would carry a coiled, notched ribbon, like the perforated sheets that drive player pianos. The launching of the torpedo would simultaneously trigger a switch on both rolls to start them turning at the same time, the variation in notches encoding the expected changes in frequency. By hopping between several frequencies and limiting course corrections to short bursts of radio transmission, the resulting system was virtually unjammable.
It was a brilliant system that had just one problem – the Navy, who would have borne the responsibility for producing it, were piss-awful at making torpedoes. In the first months of the war, most of their torpedoes either went under their targets or just nuzzled gently into their hull without actually exploding.
It was, pretty embarrassing, and no matter how great LaMarr and Antheil’s invention was, there was no way the Navy was going to start experimenting with it until they first figured out how to debug the humble ole Go Straight, Then Blow Up variety first.
So, though LaMarr and Antheil did receive a patent for their invention, they never saw it developed. The design was placed under lock and key and wouldn’t be seen again, as far as we know, for several decades.
Eventually, however, as the airwaves grew more and more crowded, some scheme was needed to allow devices to communicate without interfering with each other. Electrical engineers scrounging for solutions happened upon LaMarr’s forgotten work, and recognized its revolutionary worth. Dave Hughes, the father of wireless network systems for rural schools, decided that LaMarr should receive some recognition for her startling and original work, and lobbied hard to see that she received the Pioneer Award from the Electronic Frontier Foundation in 1993, an event which kickstarted a wave of late-life appreciation.
LaMarr died in 2000, the most beautiful woman in the world, the mother of the wireless age.
FURTHER READING: The whole story of LaMarr and Antheil is told in Richard Rhodes’s 2010 book, Hedy’s Folly. Be warned, though, that most of the book is taken up with a thorough detailing of the ins and outs of Antheil’s career in modern classical music, with Hedy sort of pushed to the beginning and end. If you love classical music books (and they happen to be my absolute favorite thing), this isn’t really a problem, but if you’re going in expecting to get an intimate grasp of Hedy’s life and mind, you’ll probably be a smidge disappointed.