In 1951, physicist Julian Schwinger made a breathtaking prediction. According to quantum theory, if you could apply an unimaginably strong electric field to the emptiness of space, something extraordinary would happen: particles of matter would spring into existence out of nothing. Specifically, pairs of electrons and their antimatter twins, positrons, would tunnel into reality from the quantum vacuum.
This idea, known as the Schwinger effect, electrified the imagination of scientists and science fiction writers alike. Was this the first step toward the “replicators” of Star Trek, machines that conjure meals and objects out of thin air? Could it unlock a new way of harnessing the hidden energy of the vacuum itself?
The problem was sobering. To generate electron–positron pairs in this way would require electric fields so colossal that no conceivable laboratory on Earth could create them. For decades, the Schwinger effect remained purely theoretical—an elegant but unreachable corner of quantum physics.
Quantum Tunneling: The Mystery in the Vacuum
To understand why Schwinger’s idea is so radical, it helps to remember that in quantum mechanics, nothing is never truly nothing. What we call a vacuum is not an empty void but a seething landscape of fluctuating fields. Virtual particles—tiny, fleeting disturbances—are constantly appearing and vanishing in timescales so short they usually escape notice.
Quantum tunneling, the process that underpins Schwinger’s theory, is the strange ability of particles to leap across barriers they seemingly shouldn’t be able to cross. It defies everyday intuition, yet it has been confirmed countless times in experiments and even powers technologies we rely on, from semiconductors to nuclear fusion in stars.
Schwinger realized that if an electric field were strong enough, it could tip the scales so that virtual particles became real ones—no longer ghosts, but actual matter. It was a vision of creation itself, playing out on a quantum stage.
A New Approach from Superfluid Helium
Now, over seventy years later, physicists at the University of British Columbia (UBC) have proposed a daring new way to explore this idea—by using an entirely different system as an analogy to the vacuum of space.
Instead of trying to summon particles with impossible electric fields, Dr. Philip Stamp and colleague Michael Desrochers suggest looking at superfluid helium-4, a bizarre state of matter that behaves as though it has no viscosity or resistance to flow. At temperatures close to absolute zero, a film of helium only a few atoms thick becomes effectively frictionless, moving like a liquid with no internal drag.
When this ultrathin film flows, something remarkable can happen. Instead of electron–positron pairs appearing, as Schwinger imagined, pairs of vortices and anti-vortices can suddenly form within the superfluid—tiny whirlpools spinning in opposite directions, born spontaneously from the flowing “vacuum” of the liquid.
It’s not matter popping into existence, but it’s strikingly similar in principle.
Why Superfluids Are the Perfect Playground
Superfluid helium is often described as a kind of laboratory for the cosmos. Its peculiar properties mimic conditions we can never create directly: the vacuum of deep space, the turbulence inside black holes, even the extreme physics of the early universe.
“Superfluid helium-4 is a wonder,” says Dr. Stamp. “At a few atomic layers thick it can be cooled very easily to a temperature where it’s basically in a frictionless vacuum state. When we make that frictionless vacuum flow, instead of electron-positron pairs appearing, vortex/anti-vortex pairs will appear spontaneously.”
In other words, the fluid becomes a kind of stage where the impossible can be rehearsed in miniature. Instead of peering into the unreachable quantum void of empty space, researchers can watch analogous processes unfold in the laboratory, with systems they can actually manipulate and measure.
Beyond Analogy: A New Physics of Vortices
What makes the UBC work especially exciting is that it goes beyond analogy. While the comparison to cosmic phenomena is captivating, Stamp emphasizes that superfluid helium is a real system in its own right, one that can teach us new lessons about phase transitions, quantum behavior, and two-dimensional matter.
To make their model work, Stamp and Desrochers had to rethink some long-standing assumptions. Traditionally, physicists treated the mass of a vortex in a superfluid as a fixed constant. But their calculations revealed that as vortices move, their effective mass changes dramatically. This insight transforms how scientists understand vortex dynamics, with implications not only for condensed matter physics but also for early-universe cosmology.
“It’s exciting to understand how and why the mass varies, and how this affects our understanding of quantum tunneling processes,” explains Desrochers. “These processes are everywhere—in physics, chemistry, even biology. Seeing them in a new light reshapes the foundations of how we think about them.”
The “Revenge of the Analog”
One of the most intriguing aspects of the UBC research is that the lessons learned from the helium experiment may feed back into our understanding of the original Schwinger effect itself. If vortex mass can vary in superfluids, then perhaps electron–positron pair creation in a vacuum is also more complex than Schwinger envisioned.
In this sense, the analogy comes full circle: what began as a way to simulate the unreachable phenomenon may actually modify the original theory. Stamp calls this the “revenge of the analog”—a playful phrase that captures the deep interplay between models, metaphors, and the real world in theoretical physics.
Why It Matters
At first glance, the spontaneous appearance of vortices in a cryogenic liquid might seem far removed from the great mysteries of the cosmos. But physics often works this way. Small, controlled systems can serve as windows into the most profound questions.
The UBC work not only advances our knowledge of superfluids and vortex dynamics—it also provides an experimental handle on concepts once thought to be forever beyond reach. It shows us how careful analogies, tested with rigor, can deepen our understanding of both the quantum world and the universe at large.
And perhaps most importantly, it reminds us that science is as much about imagination as it is about measurement. To bridge the gap between the impossible and the observable requires creativity, boldness, and the willingness to chase ideas that border on the fantastic.
A Never-Ending Story of Curiosity
Julian Schwinger’s dream of matter created from nothing may still lie beyond our laboratories. But through the shimmering, frictionless flows of superfluid helium, we are taking steps closer to grasping its essence. Each new insight into vortices, tunneling, and fluctuating vacuums adds another piece to the puzzle of how reality itself emerges.
From the depths of space to the thinnest films of helium, physics continues to reveal that the universe is stranger—and more wondrous—than our imaginations alone could ever conjure. And that, perhaps, is the true beauty of science: not only to explain, but to astonish.
More information: Vacuum Tunneling of Vortices in 2-Dimensional 4He Superfluid Films, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2421273122
