Waves of light reflecting off waves of dark water: that’s the image Andrea Schmidt, co-creator of the first viable alternative to conventional antennas, conjures when she tells the story of the night that she and her colleague, John Singleton, won three R&D 100 awards, known as the Oscars of innovation. It was November 28, 2022, and they were on a beach on California’s Coronado Island while scientists dressed to the nines mingled in a hotel ballroom behind them. Singleton, a Los Alamos physicist, wore a tuxedo; Schmidt, a Lab antenna engineer, wore a gown with the same pearl necklace she always wears. Neither said much. “We’ve always had a thing for waves,” Schmidt says. They just sat in exhausted and exhilarated silence and watched wave after wave wash ashore.
Antennas have never been more valuable, more prevalent, or more strained than they are now. The world is home to twice as many devices as people, nearly all of them connected wirelessly via antennas. Last year, people devoured 60 times more data than they did in 2010, with an estimated 90 percent of the data ever generated consumed in the last two years alone. As technology tugs the world deeper into the artificial intelligence (AI) revolution, data consumption will only accelerate. What’s rarely talked about is that antennas both animate and constrain a world that computes mostly wirelessly. Conventional antennas have changed relatively little since they were invented in the 1880s. They broadcast and receive radio waves by moving electricity over the surface of metal elements.
“The current systems aren’t built to handle the coming data load,” Schmidt says. “How will your AI travel?” To date, technologists have accelerated wireless data transfer rates mostly by designing antennas that send and receive information via increasingly broad ranges of frequencies, known as wider bandwidths. But Schmidt and Singleton saw in their invention a way to modernize a 150-year-old technology and make the world faster. Instead of antennas that lose efficiency by broadcasting signals everywhere, the device they built to replicate the light that pulsars emit could optimize bandwidth usage by sending information via tightly focused beams that travel point to point—antenna to antenna.
Inexpensive, durable, high-efficiency antennas for everywhere—LightSlingers could be transformative.
Like fire hoses compared to sprinklers, these novel devices use bandwidths even more efficiently than the most technologically advanced large arrays. They’re more efficient than Elon Musk’s Starlink satellites. And, made with just five simple parts, LightSlingers, as the scientists dubbed their invention, could be made small enough to fit on silicon chips or, at the size of a baguette, be bolted onto buildings to receive high-speed satellite internet and distribute it router to router. There are 2.5 billion miles of fiber optic cables on the planet, and 2.6 billion people who lack internet access. Inexpensive, durable, high-efficiency antennas for everywhere—LightSlingers could be transformative.
They are not, though, what Singleton or Schmidt set out to build when they began their decades-long quest to understand pulsar emissions at the turn of the millennium. Which is why at that award ceremony on that Pacific beach on that November night, what Schmidt felt strongest was redemption. Recognition from the R&D 100 committee convinced her beyond doubt that all the years she’d spent in hard pursuit of a flawed idea had never been in vain. “I don’t think there’s a single scientist who ever invented anything worth inventing that had a straightforward path to success,” she says. “You have wins. You have losses. The main point is you don’t give up.”
The grand prize
John Singleton’s office at Los Alamos feels a bit like a museum—an ode to physics history. Like him, it’s very British. A sign on his office door reads, “Tea Room.” Next to it are posters and various paraphernalia from wartime Britain: “Freedom is in peril—defend it with all you’ve got.” There’s a World War II–era potentiometer, an early version of a voltmeter, that Singleton lifted from a dumpster when he was a physics professor at Oxford; a photo of modern physics’ greatest luminaries at the famed 1927 Solvay Conference; and pictures of chickens. Lots of chickens. “I wanted to be a farmer,” says Singleton, rushing into his office 15 minutes late from his “day job” as a condensed matter physicist at the National High Magnetic Field Laboratory (or the MagLab). “But the family farm went to the other side of the family.” Naturally, Singleton became a physicist instead.
“Antennas,” he says, “are my hobby.” Singleton, a Lab Fellow, began working on the idea that would become LightSlingers in the late 1990s. He was at Oxford when a student of his, Arzhang Ardavan, introduced him to his father, the Iranian mathematician Houshang Ardavan. The Ardavans wanted Singleton, a physicist uncommonly gifted at building things, to help them design a device that could prove correct the elder Ardavan’s physics-disrupting theory on why pulsars appear so bright in the night sky. Houshang theorized that the light signal emitted from the superluminal—a fancy word for faster-than-light—electromagnetic currents that pulsars produce was a natural phenomenon that decayed differently from all other forms of radiation. As radiation spreads out from its emission source, the area it covers increases and its intensity decreases. It’s why light appears dimmer at a distance. This process of decay is summed up neatly in the inverse square law, 1/R2, or one over the distance squared. But in pulsars, Arvadan was convinced he’d found an exception. He felt that the brightness of the light they produced, even after coursing across the galaxy for 100,000 light years, could only be explained by non-spherical decay, or the idea that the intensity fell off slower with distance than the inverse square law predicted.
Pulsars are massive stars at the end of their life. When unable to extract any more energy from fusion, they collapse in a supernova into an ultra-dense mass of neutrons. These dead stars, the densest things in the universe behind only black holes, also rotate with incredibly fast velocity. One pulsar, with the mass of two suns squeezed into an area smaller than the 18,000-person town of Los Alamos, was clocked at 716 rotations per second. It casts out a scything magnetic field “strong enough that if you got within several thousand miles of one, it would rip the molecules in your body to pieces,” says Singleton, pausing for a moment to reflect. When Jocelyn Bell Burnell discovered pulsars in 1967, the light she detected was so regular and precise that she called them “LGMs,” for Little Green Men, because it was inconceivable how nature could produce such an immaculate signal.
“I wonder if I can find the movie, actually,” Singleton says. He rummages through the files on his computer and pulls up a video of a stadium wave in Russia where bleachers of soccer fans stand up and sit back down sequentially. Nobody actually changes position, but the wave the sports fans form loops around the entire stadium in a matter of seconds. That’s the same way the polarization currents caused by pulsars work, Singleton says. Because it’s not an actual thing with mass, the current can do what Einstein’s law of relativity says particles cannot. It can break the universal speed limit and move faster than the light it emits. (Photons emitted by polarization currents still abide by the universal speed limit.) As the pulsar’s magnetic field passes through the surrounding plasma, positively charged particles move in one direction. Negatively charged particles move in the opposite direction, and the resulting imbalance—polarization—induces an electromagnetic wave. As the magnetic field expands faster than light, more electromagnetic waves are released. This is the light, the signal, that can be seen from Earth.
Singleton jumped at the chance to work with the Ardavans. If he could build a device that replicated this faster-than-light polarization current and prove Houshang’s theorem of non-spherical decay, the implications were tremendous. Not only did the idea challenge a bedrock law of physics, but such a device would create a signal, unlike all others, that did not grow fainter (as quickly) the farther it traveled from its source. At first, Singleton saw the idea as a way to dwarf synchrotrons, the massive and hugely expensive cylindrical particle accelerators that are used to study the origins of the universe. But the technology could also dominate the telecommunications industry. As Schmidt would write in her dissertation more than 20 years later, succeed and they’d be “very rich and famous indeed.”
A friend named Bessie
“Oh, yes, of course I remember when I started working on LightSlingers,” says Schmidt, tugging apart a blueberry muffin at a Los Alamos coffee shop that smelled like piñon smoke. It was a summer afternoon, and she was dressed casually with a string of pearls around her neck. “Joe Fasel, my mentor at the time, came bouncing into my office and said, ‘Good news, kiddo'—I was 40—‘John Singleton’s putting together a team to build the first superluminal antenna.’” That was in 2004, a decade after coming to Los Alamos from her native Switzerland, where she had studied linguistics and worked as a journalist. Schmidt had just been hired at the Lab as an undergraduate mathematician. LightSlingers was her first major project.
By then, Singleton and the Ardavans’ work had already caused a stir in the physics community. In England in 2002, they built, as a “pure physics experiment,” a device Singleton dubbed the polarization synchrotron. Their first attempt at a pulsar-in-miniature was based on Ardavan’s theoretical work. It was 6 feet long and mounted on a scissor lift. After testing it on an English runway, the team reported radio emissions from a current that traveled faster than light, a shocking announcement in its own right, while also suggesting that the radiation could have decayed non-spherically. The news was met with instant backlash. Science magazine wrote that the “revolutionary device polarizes opinions.” Russian Nobel laureate Vitaly Ginzburg enthusiastically endorsed evidence of faster-than-light polarization currents, an idea he first posited in the 1970s, and the British Nobel laureate Anthony Hewish declared the idea that the device produced anything but conventional radiation “nonsense” and “simply wrong.” The polarization synchrotron failed to conclusively demonstrate non-spherical decay, and it had leaked most of the radiation it did generate out of its amplifiers. But Singleton and the Ardavans had shown promising evidence that polarization currents could be accelerated beyond light speed.
Not long after arriving at Los Alamos from Oxford, Singleton revived his antenna hobby with a project that asked whether polarization currents could be used to transmit information. This initial effort produced two key findings. The first was a theoretical model conceived by Schmidt, who came to the project when she was still an undergrad, of a single point source—one point rather than an entire polarization current—that accelerated beyond the speed of light. “You have to simulate one particle to simulate a whole current,” Schmidt says. The second key finding was theoretical evidence that the scientists could embed messages in the current with an encoder.
The 100-pound device looked like an engine block and filled most of a pickup bed, but on a cool day in November 2011, Bessie performed a scientific first.
For the next six years, Singleton and Schmidt worked to build something far sturdier than the polarization synchrotron that could demonstrate their theory. But a machine that could generate faster-than-light currents had never been conceived of. The engineering challenges seemed insurmountable. “The ability to share knowledge and skills, the chance to run experiments that are only possible through big science—that’s a large part of why I came to the Lab,” says Singleton. For help, he reached across the canyon from the MagLab to Bruce Carlsten, who was then leading a group of engineers and physicists at the Lab’s particle accelerator. With Carlsten’s advice, a team, including Zhi-Fu Wang, Frank Krawczyk, Quinn Marksteiner, Bill Romero, and others, was assembled to build a ground-based pulsar.
The first task was emulating the charged particles found in the plasma atmosphere surrounding pulsars. Rather than using plasma, which is unwieldy, the team replicated this environment with a solid piece of alumina dielectric—an electrical insulator, made from aluminum oxide, that contained positive and negative ions. To the top and bottom of the dielectric, the team installed electrode pairs that could move the polarization current along the length of the alumina. They formed these devices into wedge shapes and assembled 72 of them into a circle. Picture half an orange. “I called her Bessie,” Schmidt says. “Something I think my middle-aged male colleagues found confusing.” When Bessie’s electrodes were switched on sequentially, the device applied an electric field to one wedge of the alumina so that the negative and positive charges within moved in opposite directions. This electrical polarization, the current that induces the signal, could then be accelerated around the circle by switching on each wedge’s electrode pair at increments of tens to hundreds of picoseconds (one picosecond equals one trillionth of a second). In the business end of the machine, a polarization current rotating at faster-than-light speed approximated the emission produced by pulsars. Singleton compared the way the device worked to a drum line in a high school marching band. Each player's arms move slowly, but with careful timing, a large enough group could theoretically be organized to create a supersonic drumroll.
Completed in 2010, the 100-pound device looked like an engine block and filled most of a pickup bed, but on a cool day in November 2011, Bessie performed a scientific first. Singleton and Schmidt wheeled her out of the warehouse where she was built and took her to the Los Alamos airport. They set up a receiver 500 meters away, fired Bessie up, and erased any lingering doubts about faster-than-light polarization currents. On a monitor, the current’s signal produced the signature cone shape of Cherenkov radiation, the peculiar blue radiation known to appear only in water after charged particles from decaying nuclear material move faster than light (light moves more slowly through water than through air, making it possible for electrically charged particles with mass to be accelerated beyond the speed of light in water). Only this time, Schmidt and Singleton had witnessed the unmistakable signature in air. “We’d cracked open a promising and entirely unexplored field in electrodynamics,” Schmidt would write years later. They had generated faster-than-light motion.
A dream decays
Around the same time that Bessie showed that faster-than-light polarization currents were possible to produce in air, the team’s focus became getting their tiny pulsars to work as antennas. By then, iPhones had been out for four years, and 4G networks had spread across much of the globe. The wireless infrastructure market was already worth tens of billions of dollars and forecast to rise to 386 billion dollars by 2032. LightSlingers had its market. “We knew our antennas worked, and that with some improvements, they could work better than existing technology,” says Schmidt. Now they had to convince the world. At first, it seemed like an easy sell. On the strength of Bessie’s results and Ardavan’s theory, the team landed a partnership with a major international antenna company in 2012. “If this works, if non-spherical decay works,” Schmidt remembers thinking, growing animated in the coffee shop, “we could absolutely revolutionize the telecommunications industry.”
But non-spherical decay remained a controversial idea. The scientific dispute that Singleton and the Ardavans had kindled in 2002 with their first device had only intensified. Schmidt called it “vitriolic and very public.” More than 14 papers had been published arguing over the concept’s plausibility, with long and heated debates spilling into articles' comments sections and conference lobbies. “We had scientists walk out of our presentations. One, and I distinctly remember this, even said, ‘Ba-humbug’,” Schmidt says with a laugh. Publicly, the team remained steadfast in their belief that Ardavan’s theory of non-spherical decay was sound and that their devices were on track to prove it. But privately, doubt had begun to creep in. Not one of their tests had generated proof of non-spherical decay. Ardavan insisted the fault lay with the antennas, and the antenna company agreed. “So we built more devices,” said Schmidt.
Over the next few years, the team built six different antennas, each time improving the design with tweaks that they hoped would demonstrate not only faster-than-light polarization currents but also Ardavan’s theory of non-spherical decay. They invented an entire field as they went. Bessie was shrunk. One proposed design nested on silicon chips; another was the size of a football field. The electrode pattern went from cylindrical, mimicking pulsars, to linear, because it was easier to build, cheaper, and “we wanted to know if it worked,” says Schmidt. It did, and with the simplicity of the new linear design and the materials used, the scientists showed it was possible to build LightSlingers into nearly anything: chimneys, house siding, tank armor. To isolate and observe the signals emitted by the polarization currents, Singleton built an anechoic chamber the size of two shipping containers. The interior of the vessel was quilled with two-foot-long foam spikes that absorb radio waves. They drove their antennas to the Farm Range, an open antenna range run by Ward Patitz from Sandia National Laboratories. They were used to transmit music 75 kilometers from the Los Alamos airport to the Sandia Crest. (The first test was Louis Vierne’s choral masterpiece “Messe Solennelle.”) Each experiment confirmed that the antennas were using bandwidths far more efficiently than conventional antennas, making it possible to send more information. But because the signal could only be received in one geographic location, rather than the widely broadcast emissions of conventional antennas, the communications were also far more secure. “We began to see LightSlingers as a way to conduct operations in theaters of war much more securely,” says Singleton.
While he directed the build and design of the devices, Schmidt focused on modeling their emission patterns—the signals. How did an entire superluminal current move? To build on her earlier efforts, she consulted scientific history. What was already known about the behavior of waves emitted by sources that traveled faster than the waves themselves? She studied early work from Russian physicists on Cherenkov radiation, tapped into research on differential equations by the Russian mathematician Sofia Kovalevskaya, applied James Clerk Maxwell’s theories on electromagnetic radiation, and used George Green’s 200-year-old methods to describe how electricity flows. Most applicable, though, were astrophysicist Thomas Gold’s theories on sound waves. In 1952, Gold traveled to Britain’s Farnborough Air Show to listen to the sonic booms left behind by supersonic jets. He wrote that it “sounded like cannon fire” and was as “palpable as ocean breakers.” His description of multiple wave fronts, originating at different points in time and all hitting him at the same moment, were poignantly reminiscent of Schmidt’s own observations of the currents that Bessie had produced at the Los Alamos airport. One was a loud bang, the other, a bright flash; but both, as Gold called the phenomena, were temporal focusing.
The more Schmidt learned and the more data the antennas gave her to work with, the more she grew convinced that non-spherical decay was a false promise. Every observation reverted back to Maxwell’s equations on electromagnetic radiation. By around 2015, Schmidt had grown convinced that shackling the superluminal model of pulsar emissions, which they had convincing evidence for, to the concept of non-spherical decay, which they did not, was what she called “a great blunder.” But where, exactly, had Ardavan gone wrong? She spent most of the next six years meticulously deconstructing Ardavan’s theorems, some of which sprawled across 60 pages. “Then one day, it hit me like a freight train,” she said. “The only way his math made sense was by assuming that superluminal currents were coming back from infinity.” This flawed calculus changed the way the math represented how polarization currents behave. And when Schmidt deleted the mirror at the edge of infinity, a boundary condition in the equation, a surprising thing happened: the emissions from superluminal currents decayed in exact accordance with the inverse square law. It raised a daunting prospect.
“In the absence of non-spherical decay,” Schmidt asked. “How can light that travels for hundreds of thousands of light years stay so bright?”
“In the absence of non-spherical decay, how can light that travels for hundreds of thousands of light years stay so bright?”
Redemption
One late summer evening, Schmidt and Singleton walk along the concrete floor of a long warehouse that looks like something out of an Indiana Jones movie. Their footsteps echo against the high ceilings. They’ve come to visit Bessie. Six generations of LightSlingers have passed since her fabrication, and she’s become something of an artifact that is now stored in a warehouse adjacent to the MagLab. Several hundred yards down a corridor edged with shelves storing wires and various industrial parts and equipment used to power big science, the scientists veer right into one of many small bays. There, on a wooden pallet set against the anechoic chamber Singleton built to test her, sits Bessie. Light is glinting off her aluminum exterior, and she looks more like a motor removed from a broken washing machine than the future of antennas. Schmidt pats her affectionately. “Beautiful, right? She’s my baby,” she says, having just returned from Alaska, where she’d gone to help install a large array of conventional antennas. “If you asked me to scrap her, I’d say, ‘Absolutely not. Never.’”
In 2016, not long after Schmidt presented her findings on non-spherical decay to Ardavan and the commercial antenna company, the entire LightSlingers project very nearly became, like Bessie, an artifact. The team split. Ardavan and the company refused to accept Schmidt’s unwelcome evidence and kept doggedly chasing the (still unproven) theory of non-spherical decay. Schmidt and Singleton left the project and antennas, they thought, for good. “It was devastating, worse even,” says Schmidt. “We’d lost the grand prize. We’d lost non-spherical decay. We’d lost the antenna company. But it was also embarrassing. We’d spent decades defending a theory that was clearly wrong.”
In the partnership’s wake, Schmidt shifted to writing her dissertation on LightSlingers, a compendium of research on superluminal currents. In it, she tackled the question of the brightness of pulsar emissions. If not non-spherical decay, then what explained pulsars’ regular flashing light? Clues lay in the observations of the antennas they’d built. When the receiver was just off target from the emission source, the signal LightSlingers emitted was incoherent. The radio waves were superposed out of sync, and the amplitude greatly decreased. In fact, the signal was only coherent at a single point. This suggested that the visible light from pulsars moved in much the same way as the sonic booms that Gold had observed at the 1952 airshow. They’re both beams. The light traveled in a dense packet of photons that, though emitted at different times, all arrived at the same place in a single decisive flash: that short, bright, and clear pulse of light visible from Earth. What Schmidt laid bare in her dissertation is that pulsar emissions don’t have to break the inverse square law to remain bright. Light’s equivalent of sonic booms, pulsars are nature’s most powerful beam makers. And the only thing better at forming beams than dead stars, Schmidt now knew, are LightSlingers.
Meanwhile, Singleton’s interest in LightSlingers was maintained when he won a series of small grants that let him keep testing and perfecting the linear antennas. One aim of the work was to decisively demonstrate LightSlingers information-focusing abilities; another was to show how inexpensively and efficiently they could be made. Conventional antennas are built in international factories with more than 200 parts sourced from all over the world. LightSlingers are built with five. Singleton took his designs to an Albuquerque shop and had a Lightslinger 3D printed and milled, with materials sourced locally, for several hundred dollars. The result of Schmidt’s calculations and Singleton’s engineering was the seminal paper that eventually led to the R&D 100s award and the pair’s trip to California.
COVID-19 broke out around the same time that the paper was published, closing schools and forcing tens of millions of kids into years of remote learning. The sea change in education relied on kids having access to high-speed internet. Between 16 million and 20 million American children didn’t. They were cast onto the wrong side of the digital divide, in extreme cases, because they lived in remote places where it could cost a hundred thousand dollars to stretch internet cable just one additional mile. “A light bulb went off for us,” says Schmidt, now sitting on the pallet beside Bessie. “We finally understood just how valuable our antennas could be. If we could get our antennas out into the world, we could help close the digital divide.”
Soon after completing her Ph.D., nearly 20 years after she began her science career at the Lab as an undergraduate researcher, Schmidt was hired as a staff scientist. Now she and Singleton hope to debut LightSlingers over the next year in New Mexico where, if all goes as planned, they’ll be used to promote digital equity by sending high-speed internet from satellites or fiber-optic cables to house-to-house networks in native Pueblos or remote corners of the Navajo Nation. Singleton sees this “last mile” application as a trial run—closing the digital divide locally to demonstrate the antenna’s potential globally. The market size for just the third of the world’s population that lacks internet is an estimated 74 billion dollars.
“I’m convinced now that this is the right technology for this century,” Singleton says, silencing the phone buzzing in his pocket. He’s needed at the MagLab. Singleton politely excuses himself and waves goodnight to Schmidt before heading back through the vast warehouse. As he goes, he passes two saucer-shaped antennas, sitting idle on a shelf and aging far faster now than they were just a few years ago. LDRD