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Mother of invention

In the movies, inventors are invariably men and usually a bit mad. In the real world of wireless communications, one of the most important inventors was a woman...and a Hollywood actress.

Janet Paterson
By Janet Paterson, Editor, ITWeb Informatica
Johannesburg, 21 Aug 2014

Other mothers of invention

Adeline DT Whitney (1824 - 1906) - Alphabet blocks
Being a poet and writer, Adeline DT Whitney was bound to come up with an invention of this magnitude, which is, to this day, still relevant and essential to child development. Although altered and changed for the better over the years, she was the brains behind alphabet blocks.
Elizabeth Magie (1866 - 1948) - Monopoly
In creating the game, initially known as 'The Landlord's game', Elizabeth Magie was, in essence, trying to explain how Henry George's system of political economy would work in real life.
Tabitha Babbitt (1784 - 1853) - The circular saw
Unlike many other women in her time, Tabitha Babbitt was a toolmaker and invented quite a lot throughout her life. The spinning wheel head, false teeth and the circular saw are just some of her inventions.

In 1933, 18-year-old Hedwig Kielser was gaining notoriety for her on-screen orgasm simulation in the film Ecstasy. A decade (and past-escaping name change) later, Hedy Lamarr was collaborating with composer friend George Antheil on 'frequency hopping', the precursor for spread spectrum - the technology behind just about every wireless device in our lives today.

Somewhere in between, Lamarr found time to become Hollywood's go-to sultry seductress, starring alongside Spencer Tracy, Clark Gable and James Stewart. And embark on her third of six marriages.

It was the first of these marriages - to arms dealer and Nazi-sympathiser Friedrich Mandl - that set Lamarr on the path to technology's hall of fame. Mandl was so possessive that he insisted his young wife accompany him to business meetings, where military technology was discussed in detail. Lamarr may have famously said: "Any girl can be glamorous. All you have to do is stand still and look stupid", but it's clear that she did a lot of listening while standing around looking good.

Patently genius

On 11 August 1942, US Patent 2.292,387 for a 'Secret communication system' was granted to Lamarr and Antheil. "The invention relates broadly to secret communication systems involving the use of carrier waves of different frequencies, and is especially useful in the remote control of dirigible craft, such as torpedoes. The object of the invention is to provide a method of secret communication, which is relatively simple and reliable in operation, but at the same time is difficult to discover or decipher ..."

The primitive system used a mechanical switching device based on an automatic piano's paper roll to switch control frequencies faster than enemy engineers could keep up. Because there are 88 keys on a piano, the device allowed hopping over 88 frequencies.

Not a bad result for a friendship that began as a dinner party conversation that ended with Lamarr scrawling her number in lipstick on Antheil's windscreen so they could develop their ideas further.

The idea behind frequency hopping is relatively simple. Rather than transmitting over a single frequency, a 'spread' spectrum switched from one frequency to another. The frequencies 'hopped' are random, which makes the system secure. The issue is to ensure that the receiver and transmitter are co-ordinated, something that is achieved with precise clocks and random number generators. Recently, spread spectrum has been combined with digital technology for undetectable and noise-resistant war-zone communications. In ordinary life, it's all around us in LANs and WiFi.

Too bad for Lamarr the US Navy didn't spot the value in her vision - which was offered free of charge - and declined to use it against the Nazis. It wasn't until the Cuban Missile Crisis in 1962 that the military made use of the technology for signal jamming, rather than her intended torpedo guidance system. By then, the patent had been expired for three years and neither Lamarr nor Anthiel (who died in 1959) profited from it.

The foundation

Frequency hopping is today largely seen as an invention ahead of its time; by the time people understood its possibilities, other, more effective technologies had been discovered. A major drawback for Lamarr and Anthiel's invention was the requirement that both transmitter and receiver be in perfect synch (otherwise, all the frequency hopping is pointless).

All creative people want to do the unexpected.

Hedy Lamarr

By the 1950s, Code Division Multiple Access (CDMA) - a version of spread spectrum that doesn't need frequency hopping - had been developed and the foundation stone for mobile communications as we know it today was well and truly laid. It was only when the wireless and mobile revolution truly got underway in the 1990s that Lamarr and Anthiel's contribution was re-discovered and recognised for what it was. In 1997, the pair were awarded the Electronic Frontier Foundation's 'Pioneer Award' - almost 40 years after Anthiel's death.

Lamarr died in 2000, at the age of 86. She once declared that, throughout the course of her life, she had earned and spent over $30 million but in old age could barely afford a sandwich.

Sometimes truth is stranger than fiction and appearances deceive. Hedy Lamarr's life and achievements proved both.

First published in the August 2014 issue of ITWeb Brainstorm magazine.

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