American Scientist

If you have even a passing interest in science, you’ve heard that Albert Einstein was a poor student and created his revolutionary theories without any awareness of the scientific progress taking place around him. If you have seen last year’s film Oppenheimer, you’ve heard that Los Alamos scientists were terrified by the prospect that an atomic bomb’s detonation would ignite the atmosphere, destroying life on Earth. If you have seen the 2017 documentary Bombshell, you’ve heard that 1940s screen star Hedy Lamarr invented the basis for all modern communication technology, including the internet.

These stories have many things in common. They take the collective, largely anonymous advance of science and reduce it to a single, relatable—at least recognizable—individual. By compressing space and time, they heighten the drama of what is usually an incremental tale of trial and error. Like the Terminator and certain rumors concerning elections, they are notoriously hard to kill. They are all untrue.

The legend of Hedy Lamarr begins in 1942 when she and her partner, composer George Antheil, received U.S. patent 2,292,387 for a “Secret Communication System,” which employed the encryption method today called frequency hopping, a form of the more general technique known as spread spectrum. When a frequency-hopping system sends a message, the transmission frequencies jump around in a seemingly random pattern, making it almost impossible to intercept the message, except by a receiver hopping around in synchrony with the transmitter. Over the decades, a stream of claims convinced millions that Lamarr’s invention laid the foundation for Wi-Fi, Bluetooth, GPS—nearly all modern communication technology that we take for granted today. Her 100th birthday doodle on Google in 2015 and Bombshell two years later inextricably embedded the legend in popular consciousness.

In my January–February 2019 article, “Random Paths to Frequency Hopping,” I presented a number of patents and proposals that antedated Lamarr and Antheil’s, some of which clearly employed frequency hopping, others of which came infinitesimally close. The producers of Bombshell were aware of those systems: As technical advisor to the production, I gave them all the patent numbers and invention descriptions. No mention of the prior patents appears in the film.

Now incontestable evidence shows that the U.S. Patent Office itself dismissed the idea that Lamarr and Antheil were first to propose frequency hopping. David R. Irvin, a patent agent and engineer with 44 patents to his credit, has examined the original documents related to the invention, which are preserved by the Patent Office and the Smithsonian Institution’s National Museum of American History. This source material includes the original patent application as well as the patent examiner’s response.

The bulk of any patent application is taken up by technical specifications, but more important are the claims—a list explaining what is new about the invention. The published Lamarr–Antheil patent makes six claims regarding the operation of their specific device. All of them refer to a “record strip,” whose punched holes control the “plurality of frequencies” that are transmitted and received according to the (random) hole pattern. But from a letter dated October 3, 1941, to Lamarr and Antheil from their patent attorneys, Lyon and Lyon, we have long known that a seventh claim had been rejected by the examiner.

What was in the lost seventh claim? Irvin has solved the mystery. The inventors claimed:

7. In a radio communication system comprising a radio transmitter tunable to any one of a plurality of frequencies and a radio receiver tunable to any one of said plurality of frequencies, the method of effecting secret communication between said stations which comprises simultaneously changing the tuning of the transmitter and receiver according to an arbitrary, nonrecurring pattern.

This claim is much broader than the others; it is the very definition of frequency hopping. Had the patent examiner accepted it, Lamarr and Antheil could have made a case that they’d originated the concept. But the examiner rejected claim 7 on the grounds that frequency hopping was already known.

As evidence, the examiner cited two earlier patents that fully covered the claim. The first was U.S. patent 1,869,659 granted to Willem Broertjes in 1932, and a second was U.S. Patent 2,134,850, granted in 1938 to Martin Baesecke of the German firm Siemens and Halske. The Broertjes patent was extensively discussed in my 2019 article; Baesecke’s patent, unknown to me then, apparently represents an improvement of the “frequency wobbling” technique proposed in patents by Ellison Purington and Emory-Leon Chafee, which the article did discuss.

Lyon and Lyon agreed with the examiner, writing in their letter, “. . . we rather doubted at the time that method claim 7 would be considered patentable, since the invention appears to reside more in a new apparatus than in a new method.” They suggested that the inventors might improve their device by inserting a new claim (for a fee of $25) that was not limited to a record strip, but the pair never took action.

Irvin’s findings prove that Lamarr and Antheil did not invent frequency hopping. And contrary to the legend that their patent had been classified as critical to national security, the letter from Lyon and Lyon stated clearly that it had not. Irvin further highlights the groundlessness of that legend by presenting three successive patents issued on August 11, 1942: The Lamarr-Antheil patent took less time to process than those before and after it, indicating that no secrecy review took place. Moreover, no reference to Lamarr and Antheil’s device appears in the patents underlying the first frequency-hopping system put into action (BLADES, developed by Sylvania Electric’s Buffalo Labs division) or in R.C. Dixon’s Spread Spectrum Systems, the first textbook devoted to the field, which cites nearly 2,000 technical papers.

The ultimate moral to this tale is that science is a collective endeavor if there ever was one, an enterprise that relies on evidence, logic, and corroboration. Here is an idea genuinely worth repeating: Lone inventors and discoverers almost never act alone.