Gravitational-Wave Communication on a Chip

April 24, 2026

Gary Stephenson wants to test whether superconducting Josephson junctions etched onto a wafer can make gravitational waves carry signals where radio cannot: through rock, seawater, underground spaces, and other places ordinary electromagnetic signals struggle to reach. His proposal imagines a cold, chip-scale array that could push established superconducting electronics toward an extraordinary purpose—turning gravity itself into a communications medium. The hardware path is concrete enough to describe in wafers, materials, frequencies, and cryogenic test gear. But the central physics remains unproven, the device has not yet produced a validated gravitational-wave signal, and the message Stephenson hopes to send has not yet been heard.

Gary Stephenson’s Bet on a Gravity-Based Signal

Gary Stephenson is not claiming that he has built a working gravitational-wave communicator. What he is proposing is earlier, stranger, and in some ways more interesting: a test of whether a superconducting device can make gravity useful at laboratory scale. In his presentation, Stephenson describes himself as the technical design lead for a collaboration that tried to turn an obscure line of gravitational-radiation theory into something that could be fabricated, cooled, powered, and measured. His subject is exotic, but his language often returns to practical things: wafers, junctions, cryogenic probes, test houses, and how to keep a device cold enough to work.

The idea, in lay terms, is to build a tiny electronic structure that does something ordinary superconducting electronics already do—oscillate with extreme precision—and then ask whether a special version of that structure can do something extraordinary. The device would use Josephson junctions, components made from superconductors separated by a thin barrier. Josephson junctions are real, established devices. Stephenson’s twist is to make the two sides of the junction different kinds of superconductors, then drive them in a way that might favor a gravitational form of radiation rather than an ordinary electromagnetic one.

The appeal is easy to understand even if the physics is not. A normal transmitter sends electromagnetic waves, which can be blocked, absorbed, reflected, or scattered by water, rock, metal, terrain, and the curvature of the Earth. A gravitational-wave transmitter, if one could be built, would send ripples in spacetime itself. Those ripples would not care much about seawater, mountains, mines, or walls. In principle, a signal like that could reach places where conventional communication struggles.

That is the exciting version. The cautious version is just as important: no one has shown that Stephenson’s proposed device can generate a usable gravitational-wave signal, and no one has demonstrated the kind of photon-to-graviton conversion on which the concept depends. The story therefore begins not with a breakthrough, but with a wager. Stephenson’s proposal asks whether a mature technology from superconducting electronics can be pushed into one of the least forgiving domains in physics: making gravity speak on command.

The Places Radio Cannot Go

The reason Stephenson’s wager is tempting is that the problem it addresses is not imaginary. Radio is one of the great technologies of modern civilization, but it is not magic. It bends, scatters, reflects, attenuates, and dies. The deeper a receiver goes into seawater, rock, metal, or reinforced structure, the more communication becomes an exercise in compromise. A signal that works across open air may become useless underground. A transmitter that can reach across continents may struggle to reach into a submarine.

That is the practical world Stephenson begins from. He names mineshafts and submarines, but the category is broader: underground facilities, disaster sites, deep-sea platforms, hardened shelters, remote scientific stations, and any place where line-of-sight communication is blocked. The problem is old enough that whole families of workaround technologies have grown up around it. Some use very low frequencies. Some rely on acoustic methods. Some use relays, tethers, buoys, satellites, or infrastructure placed in advance. All are constrained by the medium they must cross.

“The problem we’re trying to solve is non-line-of-sight communication. If you’re in a mineshaft or a submarine, it’s very difficult to communicate with people because they’re underground. So, how do we solve that? One way to solve that might be through non-line-of-sight communications using gravitational waves.”

— Gary Stephenson

A signal that could ignore those obstacles would be more than a clever new radio. It would change the map of communication. A trapped miner, a submerged vessel, or a buried sensor would no longer have to wait for a path around matter. The signal would pass through the matter itself. That is why the promise of gravitational-wave communication is so powerful. It imagines a carrier that does not need the usual openings, repeaters, towers, cables, or skyward view.

But the same property that makes gravitational waves seductive makes them nearly impossible to use. They pass through matter so easily because they interact with matter so weakly. The universe can send gravitational waves across cosmic distances, but human engineering has no easy way to make them on demand or catch them once they arrive. Stephenson’s project lives inside that contradiction: the perfect communication medium may also be the hardest one to control.

Why Gravity Is Both the Perfect Carrier and the Worst One

For most people, gravitational waves entered public awareness through astronomy. Black holes spiral together. Neutron stars collide. Cataclysmic cosmic events shake spacetime. Instruments on Earth, isolated from vibration and stretched over kilometers, detect tiny changes produced by enormous masses moving at astonishing speeds. The achievement is spectacular, but it also reveals the problem. It takes astronomical violence to make a gravitational signal we can measure.

Stephenson explains this by contrasting two routes to gravitational radiation. The classical route is the one nature uses in the sky: mass and energy changing their motion in a way that radiates through spacetime. The coupling is brutally weak. Human-scale masses and energies are tiny compared with black holes. A laboratory machine that tries to make gravitational waves by shaking matter in the ordinary way is fighting physics with one hand tied behind its back.

The alternative Stephenson wants to explore is a quantum route. Instead of moving large masses, his concept looks for a transition inside a superconducting device that could produce gravitational radiation directly. In simplified terms, an ordinary electromagnetic transition produces photons. A gravitational transition would involve spin-2 radiation, associated with gravitons in a quantum picture of gravity. The dream is not to detect one lonely graviton. It is to generate an enormous collective signal—something wave-like, repeatable, and measurable.

“Fair warning, gravitons have never been measured at the elemental level. They probably never will be because their interaction length is so small. So you need an enormous amount of gravitons to be able to measure a gravitational wave.”

— Gary Stephenson

That distinction matters because Stephenson himself acknowledges that individual gravitons have never been measured and may never be directly detected one by one. His proposal does not need a detector that counts single gravitons like coins. It needs a device that could create a large, coherent gravitational-wave-like signal. That is still an extraordinary burden. A quantum transition can be allowed in theory and still be useless in practice. The rate may be too small, the effect may fail to scale, and the receiver may see nothing at all.

From Forgotten Theory to a Proposed Gravitational-Wave Device

Stephenson’s presentation is not built from a single new claim. It follows a trail of older work that he treats as the conceptual foundation for the device. He reaches back to Halpern and Laurent in the 1960s, then to Ford in the 1980s, and later to Giorgio Fontana’s work on high-temperature superconductors and the idea of a gravitational laser, or GASER. These references matter because they show that Stephenson is trying to turn a theoretical possibility into a modern test article, not simply inventing the premise from scratch.

The simplified version is this: certain quantum systems may have transitions that radiate gravitationally rather than electromagnetically. In the popular shorthand of the presentation, photon-like behavior is associated with spin-1 radiation, while graviton-like behavior is associated with spin-2 radiation. Stephenson describes the challenge as finding a way to force or favor that spin-2 pathway. The question is not whether diagrams can be drawn showing such transitions. The question is whether any physical device can make them happen with useful efficiency.

Fontana’s work is the crucial bridge in Stephenson’s telling. Fontana proposed that superconducting systems might provide a route to stimulated gravitational radiation. Earlier versions of the idea involved bulk high-temperature superconductors. Stephenson’s version shifts the concept toward thin-film devices that could be fabricated using microelectronics methods and tested with infrastructure developed for superconducting and quantum hardware.

But a lineage is not a proof. Old papers can suggest a path without showing that the path can be engineered. A transition diagram is not a transmitter. A table of radiation patterns is not a receiver. A proposed gravitational laser is not a working communication system. The older work gives Stephenson’s project a conceptual ancestry, but the story still turns on a practical question: can the mechanism be made strong enough, clean enough, and measurable enough to matter?

The Superconducting Junction at the Heart of the Claim

At the center of Stephenson’s design is a Josephson junction, one of the most important devices in superconducting electronics. In broad terms, a Josephson junction is a tiny structure in which two superconductors are separated by a thin barrier. Quantum behavior across that barrier can produce exquisitely controlled electrical effects. Josephson junctions are not speculative. They are used in precision measurement, superconducting circuits, quantum hardware, and sensitive low-temperature devices.

The known effect Stephenson wants to use is the AC Josephson effect. Apply a small DC voltage across a Josephson junction, and the junction oscillates at a frequency determined by that voltage. This gives the device a way to turn a controlled electrical input into a controlled oscillation. In Stephenson’s proposed system, that oscillation would sit in the microwave range, around 24 gigahertz. That part of the story is built on established physics.

The speculative twist is the use of dissimilar superconductors. Stephenson describes a junction between different superconducting types or order-parameter behaviors: an s-wave side and a d-wave side, or, in parts of his presentation, Type I and Type II superconducting behavior. The hope is that this mismatch at the junction can force or favor the unusual spin-2 transitions needed for gravitational radiation. In other words, the Josephson junction is not just supposed to oscillate. It is supposed to become a quantum conversion engine.

That is where the evidence gap opens. The Josephson effect is real. Superconducting thin-film fabrication is real. Cryogenic microwave testing is real. What remains unproven is the gravitational conversion itself. A strong account of the project has to keep those categories separate. The reality of the supporting hardware does not imply the reality of the central gravitational claim. It only means the claim can perhaps be pushed toward a serious test.

The 24-Gigahertz Wafer

Stephenson’s proposal becomes most tangible when he describes the wafer. He imagines a silicon wafer patterned with many small emitter pads, arranged so that they can operate in synchronization. In the presentation, the dots on the wafer are not decorative. They represent an attempt to scale a weak effect by making many small sources act together. A single junction might be too faint to matter. An array, if it could remain coherent, might have better odds.

The chosen frequency is around 24 gigahertz. Stephenson connects that choice to several practical considerations: microwave-band availability, concern about ordinary electromagnetic interference, device layout, and the ability to place many emitters on a standard wafer. At that frequency, the wavelength is short enough that quarter-wave structures can fit into a compact layout. A standard six-inch wafer can hold many elements, each placed with the hope that the array acts as a synchronized source.

The array logic borrows from familiar electromagnetic engineering. If each emitter is a quarter wavelength in scale and the emitters are spaced by a full wavelength, then their outputs can be kept in phase. In radar or antenna engineering, phase coherence is a powerful tool. Many small emitters, synchronized properly, can act like a larger and more directed source. Stephenson’s layout tries to apply that intuition to the gravitational-wave concept.

The wafer is also where the materials problem becomes unavoidable. Thin-film superconducting devices are sensitive to deposition conditions, crystal orientation, oxygen content, contamination, interface roughness, film stress, thermal cycling, and geometry. The team would first have to show that the fabricated junctions behave like the theoretical junctions. The most immediate obstacle may not be cosmic at all. It may be making the right interface, proving it is the right interface, and reproducing it across an array.

The Cold Lab That Could Test the Idea

The project becomes most credible when Stephenson talks about how it would actually be tested. His early design thinking involved standard microwave connectors, such as SMA ports, but he says those connectors create a heat-loading problem. If the device must operate at low superconducting temperatures, ordinary room-temperature hardware can become part of the problem. The project therefore moves toward cryogenic probe stations and specialized low-temperature measurement environments.

This is where quantum computing enters the story—not because the device is a quantum computer, but because the quantum computing industry has helped build the tools needed to test delicate superconducting devices. Cryogenic measurement, wafer probing, low-noise readout, superconducting fabrication, and microwave-frequency control are now more available than they were in earlier decades. Stephenson suggests that this infrastructure is part of why the experiment may be possible now, even if earlier versions of the idea remained impractical.

“We’re talking about both using Type I and Type II low-temperature superconductors. This would be using test and probing technology that was developed for quantum computing, and would not have been possible without the quantum computing infrastructure out there. So that’s essentially why this hasn’t been done before.”

— Gary Stephenson

The transcript names a prospective fabrication path involving a microelectronics lab environment associated with UC Davis and a fabrication partner rendered as Ravada or Arvada Solutions. It also mentions FormFactor as a potential testing house for cryogenic probing. The transcript’s rendering of one name appears inconsistent, so a reported version of the story would verify it. But the larger point is clear: Stephenson had begun mapping the idea onto real fabrication and test capabilities.

He also says the team sought concept review from people familiar with the subject area, including Giorgio Fontana, whose work helped inspire the design, and Eric Davis, who has been associated with advanced and speculative physics topics. That is worth noting, but not overstating. Concept review is not validation. Fabrication planning is not validation. A cryogenic test plan is not validation. These details show that the project did not live only on a whiteboard. They do not show that gravity has been made to carry a message.

A Signal Is Not Yet a Message

A physicist may begin with the possibility of generating gravitational waves. A communications engineer would begin somewhere colder: the link budget. Before claims about submarines, mines, satellites, or underground receivers can be taken seriously, the system has to answer a basic engineering question. How much usable signal reaches the receiver, and how reliably can it carry information?

The practical variables are familiar from ordinary communications systems even if the proposed carrier is exotic. Bandwidth matters. Modulation matters. Bit error rate matters. So do range, receiver sensitivity, beam spread, energy per bit, synchronization, encoding, decoding, and noise rejection. A gravitational-wave channel would still need a transmitter, a receiver, a known propagation model, and a way to distinguish signal from interference.

This is why detection and communication must not be confused. A detector can wait, integrate, filter, and search for rare events against a modeled background. A communication system must transmit repeatedly, encode information, direct the signal, recover it at the other end, and do all of this with predictable reliability. A laboratory demonstration of a gravitational-wave-like effect would be remarkable, but it would not automatically become a communications platform.

The first communication milestone would be far humbler than replacing satellites or reaching submarines at sea. It would be transmitting one unambiguous, intentional bit across a controlled laboratory distance. The signal would have to be generated on command, detected independently, and recovered through controls that rule out ordinary electromagnetic leakage. Until that happens, the larger communications vision remains an application story waiting for a physics result.

What the First Convincing Experiment Would Have to Show

The most important thing missing from Stephenson’s presentation is also the thing that would change everything: a measurement. There is no report of a device producing a confirmed gravitational-wave signal. There is no receiver output that rules out ordinary electromagnetic coupling. There is no distance-scaling result, no modulation result, no independent replication, and no closed communication link. That does not make the presentation worthless. It makes it early.

A serious first experiment would need to be designed around failure as much as success. The junctions might not form correctly. The dissimilar superconducting interface might not behave as expected. The array might heat, drift, lose coherence, or produce unstable oscillations. A signal might appear but later be traced to ordinary microwave leakage. It might vanish under better shielding. It might fail to scale with distance, phase matching, or material choice in the way a gravitational explanation would require.

The controls would have to be as carefully designed as the device. The team would need matched devices that should not produce the effect: identical-superconductor junctions, altered interfaces, phase-randomized arrays, off-frequency devices, and dummy loads. It would need aggressive RF shielding, thermal monitoring, vibration control, independent receiver configurations, and blind tests in which the receiver team does not know when the transmitter is active, detuned, or running a control condition.

A modest success would not mean instant gravitational-wave communication. It might begin with a well-characterized junction that behaves as intended electrically, then a wafer-scale array that oscillates coherently, then a repeatable anomalous signal that appears under phase-matched conditions and disappears under controls. A much stronger result would be a signal detected through shielding, at distance, by an independent receiver, with behavior matching a pre-published gravitational model. The ladder is long: device success, array success, anomalous signal, gravitational interpretation, closed communication link, field application. Stephenson’s proposal is near the bottom of that ladder.

The Dream of Communication Through Matter

Stephenson’s imagination does not stop at the benchtop. In the presentation, gravitational-wave communication becomes a way to reach submarines and mineshafts, possibly even a way to reduce reliance on large constellations of low-Earth-orbit satellites. He also gestures toward gravitational astronomy, materials testing, SETI, and eventually propulsion. The vision widens quickly.

There is a reason for that. If a controllable gravitational-wave transmitter and receiver existed, the implications would be enormous. A signal that could pass through rock, water, and shielding would open communication channels that are currently difficult, expensive, or impossible. It would have obvious defense and security implications, from submarines and underground facilities to resilient communications in denied environments. It could also raise questions about detectability, interception, verification, and strategic stability long before the technology became ordinary.

“The real vision here is not just gravitational wave communications. It’s a testbed for testing all kinds of gravitational devices, gravitational materials. What would happen if we transmitted through different materials? Does it affect things gravitationally? So it’d be a wonderful materials testing bed.”

— Gary Stephenson

But visionary applications can outrun evidence. The more exciting the application, the more carefully the story must rank it. A materials testbed is closer to the proposed experiment than interstellar communication. A receiver-only gravitational astronomy concept is closer than propulsion. A one-bit laboratory link is closer than replacing satellites. These distinctions are not pedantic. They are the difference between a research roadmap and hype.

The language around the field adds another burden. Stephenson’s phrase “the age of gravitics” is evocative, but it sits near a history of gravity-control, exotic-propulsion, and breakthrough-communication claims that have often outrun their evidence. That history should not make the idea untouchable, but it should make the evidence standard strict. The right posture is disciplined curiosity: open to the test, severe about the proof.

Waiting for Gravity to Answer

The story does not need to decide whether high-frequency gravitational-wave communication is impossible or inevitable. That would force the subject into a false binary. The more honest account is that Stephenson’s proposal occupies an unresolved space between known superconducting engineering and unproven gravitational conversion physics. The communications problem is real. Josephson junctions are real. Cryogenic superconducting test infrastructure is real. The proposed photon-to-graviton pathway remains speculative.

That unresolved status is the story. A wafer layout can be drawn. A fabrication path can be planned. A presentation can name partners, advisors, materials, frequencies, and applications. But none of those things is a gravitational-wave signal. The device still has to enter the cold lab and answer a yes-or-no question under conditions that make ordinary explanations hard to sustain.

The strongest image is not a submarine receiving a message through the ocean. It is a cold wafer in a cryogenic probe station, surrounded by shielding, wired to instruments, being asked whether it can produce anything that behaves like a gravitational-wave signal. Can the array make the effect? Can a receiver see it? Can controls kill it? Can another lab reproduce it? Those questions are smaller than the promised age of gravitics, but they are more powerful because they can be tested.

Stephenson’s proposal is not yet a new communications technology. It is a proposed experiment with unusually large implications if it succeeds and a long list of ordinary ways it could fail. For now, it remains what many frontier technologies are at the beginning: a theory, a drawing, a set of parts, a handful of collaborators, and a signal no one has yet heard.