The play explores this theme in the tumultuous relationship that develops between Lamarr and Antheil. The pair succeeded in patenting their technology, and presented the concept to the National Inventors Council in , but their invention—which used a piano roll to change between 88 frequencies—was not well received.
Navy said, 'Thank you very much for the patent, Miss Lamarr—we won't be needing your services here in Washington,'" Lamarr's character laments onstage. The technology, says Singer, was far ahead of its time. Although her ideas were at first ignored, the technology which she and Antheil patented in was later used by the military—during the Cuban missile crisis in October , for example—and more recently, it has been employed in wireless technologies like cell phones.
Fittingly, Frequency Hopping is itself a highly technological production. In addition to the piece robotic orchestra developed by the League of Electronic Musical Urban Robots, the play uses a number of special effects. Singer wanted to portray "surrealist-inspired dreams and fantasies," such as objects popping out of bodies, so she incorporated two screens onto the set—one in front of the actors and one behind them.
The front screen is transparent, so the actors can perform behind it; Singer explains that it utilizes a special invisible polymer that reflects projected or solid images so that they appear in three dimensions, like holograms.
Singer hopes that these images, which are used to suggest what the characters are thinking, will help the audience peer into their minds. Already a subscriber? Sign in. Spread Spectrum History. Early spark gap "Wireless era" transmitters actually used Spread Spectrum, since their RF bandwidths were much wider than their information bandwidth. The first intentional use of Spread Spectrum, however, was probably by Armstrong in the late '20's or early '30's with wideband FM.
Both the allies and the Axis powers experimented with simple Spread Spectrum systems. Much of what was done is still shrouded in secrecy even 60 years later. The first publically available patent on Spread Spectrum came from Hedy Lamarr, the Hollywood movie actress, and George Antheil, an avant gard composer. The authors of the Spread Spectrum Communications Handbook state that the patent was processed routinely with no imposition of secrecy.
The researchers and inventions listed here are just highlights of a story that defies simple narratives. At any rate, Hedy and George were hardly alone. In January , five months after Lamarr and Antheil received their patent, U. In this case, the application was held under a secrecy order until , when Hutchinson was awarded U.
Patent 2,, In an unusually noble act for the time, Hutchinson listed a dozen previous patents for secret communication systems dating back to the s. Declassified patents from Project X also reveal a few additional pieces of prior art from the s and s. Glenn Babecki, an electrical engineer, and I have examined these early patents. Every one of them proposes ensuring the secrecy of a message by hopping unpredictably among a group of low-frequency audio channels.
In the majority of patents, the scrambled message is then transmitted by telephone line or radio along a single high-frequency carrier wave, making the system secure but not jam proof. Because the carrier wave is held at a constant frequency, we would probably not refer to this group of patents as frequency-hopping patents in the modern sense.
Patent 2,, for a secrecy scheme that incorporates the frequency-wobbling concept and so could be called frequency hopping. An even earlier Purington patent U. Patent 1,,, from , overlooked by Hutchinson also utilizes frequency wobbling. For transmission top , it merges a sent-data input A with a high data-rate bitstream B to produce a new signal C that is highly resistant to both jamming and interference.
At the receiving end, the bitstream is removed, or demodulated, to recover the original data input bottom. Illustration adapted by Barbara Aulicino. Patent 1,, In it, he writes that. According to Broertjes, then, the idea of changing transmission frequencies is already commonplace, but he argues that this approach does not prevent the interception and decipherment of the message, because a broadband receiver could pick up all the frequencies.
The Broertjes patent can be faulted in that the operation of the receiving mechanism is left largely as an exercise for the reader. One can only assume that the receiver contains a duplicate wheel, but Broertjes prefers manual operation, so it remains unclear how he intends synchronization to be effected. In an application filed in but granted only in U. Nor do the antecedents end here. Blackwell, De Loss K. Martin, and Gilbert S. Patent 1,, on September 7, The authors write:.
From a technical standpoint, their electronic implementation is superior to the Lamarr-Antheil version in all respects, and is superior to the other Bell Labs patents as well. At first glance, the patent of Blackwell, Martin, and Vernam appears to nail down the origin of frequency hopping, but the devil lies in the details. That approach implies a narrow transmission band.
They do state that radio transmission would work equally well, but they do not make clear whether that additional carrier would also hop frequencies.
Their patent therefore seems to represent audio frequency hopping, but not radio frequency hopping. The relative sophistication of the Blackwell, Martin, and Vernam patent compared with its successors demonstrates that technology does not always progress smoothly.
It also illuminates the difference between a patent produced by amateurs and one produced by professionals. In , Vernam had patented what has become known as the Vernam Cipher, in which a plaintext message is mixed with a random stream of characters to provide a coded message. The fundamental law of invention is the infinite chain of priority: Someone else always did it first.
Patent 1,, is widely considered to be one of the most important in the history of cryptography, so it comes as no surprise that within a year he participated in the invention of a secure transmission system. In the Blackwell, Martin, and Vernam patent we see the concept of frequency hopping partly realized, but the endless chain of priority ensures that, yes, the germ of the idea had appeared earlier still.
His Wireless Telegraphy , the standard textbook on the subject for many years, appeared in Germany in and in English translation in In a chapter on receivers, Zenneck discusses varying the wavelength of messages:. Zenneck does not mention that for full secrecy the wavelengths should be shifted in an unpredictable manner, but otherwise the proposal is for frequency hopping in the modern sense.
Here, Tesla might even have a legitimate claim. The receiver is designed to respond only when both signals are received. Here the chain of priority at last fades out, for if one goes much earlier, the concept of radio itself had yet to be born. No history of invention will ever be complete. Nevertheless he overlooked some, including the Lamarr-Antheil patent and the other early patents discussed here. Any approach to the history of science and technology that aggrandizes lone inventors is largely static: Beyond the snapshots of inspirational eureka moments, nothing much happens.
Yet surely in science and technology the protagonists should be the ideas themselves. The essential lessons—and excitement—from the history of science derive from observing the evolution of an idea, from its nebulous birth to the time at which it condenses into recognizable form. Ideas, in a real sense, have a life of their own. Dutch inventor Willem Broertjes described a form of frequency hopping for secure communication in a patent left filed in , a dozen years before Hedy Lamarr and George Antheil filed.
In American Telephone and Telegraph researchers Otto Blackwell, De Loss Martin, and Gilbert Vernam patented a system right that anticipated pivotal aspects of later frequency-hopping schemes, including changing frequencies by punching random holes in a telegraph tape.
If ideas are born of necessity, then the mother of secret communications has been war.
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