Physicist Finally Detects Quantum Waves After Two Years Underground

The Two-Year Vigil in the Basement: When Flat Lines Finally Became Waves

For two years, Sebastian Pedalino stared at nothing. Day after day, the physicist descended into a basement laboratory at the University of Vienna, where a six-metre vacuum chamber hummed at temperatures colder than the surface of Mars (Nature). He would check the readouts, adjust the lasers, and wait for a pattern that refused to appear. The screen showed flat lines. Noise. Ambiguity. "For two years, I was looking at flat lines," Pedalino told Newsbreak. "We were trying to see the interference pattern, but we had flat lines. And in the end, the flat line is not really helpful, as it is inconclusive." Not failure. Something worse: uncertainty about whether the experiment was even working. Then, sometime in late 2024, the lines began to ripple. Waves emerged where particles should have been. The team had done something that Stefan Gerlich, a co-author at the University of Vienna, said 15 years ago he thought was "not possible" (Yahoo). They had caught clusters of approximately 7,000 sodium atoms existing in two places at once, pushing quantum superposition to scales ten times larger than any previous experiment (Yahoo). The findings, published January 21 in the journal Nature, don't just set a record. They force us to confront one of physics' most unsettling questions: where does the fuzzy quantum world end and solid reality begin? ---

The Absurdity That Turned Out to Be Real

In 1935, Austrian physicist Erwin Schrödinger proposed his famous thought experiment as a critique, not a celebration (Nature). He placed an imaginary cat in a box with a vial of poison linked to a radioactive atom. According to quantum mechanics, until someone opened the box, the cat existed in a superposition of alive and dead simultaneously. Schrödinger found this absurd. He was trying to show that quantum mechanics, whatever its successes at subatomic scales, couldn't possibly describe the world we actually live in. Everyday objects clearly do not behave in a quantum way (Nature). We don't see cats in two places. Coffee cups don't blur into probability clouds. The universe, at human scales, appears reassuringly solid. But quantum theory does not put a limit on how big a superposition can be (Nature). The equations work the same whether you're describing an electron or an elephant. This creates a puzzle that has haunted physics for nearly a century: if quantum mechanics is universal, why don't we see its strangeness in everyday life? "Usually when people think of quantum mechanics, they associate it with small, tiny things, maybe photons, maybe electrons," Pedalino explained to Newsbreak. "But quantum mechanics itself doesn't state any limits. And that's what we are testing." ---

Building a Quantum Microscope for Giants

The Vienna team's approach required engineering precision that borders on obsessive. They constructed an interferometer consisting of three gratings made from ultraviolet laser light, not solid material, stretched across a two-metre span (Yahoo, Sciencefocus). The entire apparatus sat inside the six-metre vacuum chamber, cooled to 77 degrees kelvin, or −196°C (Nature). Here's how it works. The team generated a beam of sodium nanoparticles, each cluster approximately 8 nanometres wide, roughly the size of some viruses (Yahoo). They aimed this beam at the first grating, which narrows the particle's position (Sciencefocus). This is where quantum mechanics takes over. The uncertainty principle causes the particle's motion to spread out like a wave after the first grating (Sciencefocus). The second grating then causes the wave to spread across multiple gaps simultaneously (Sciencefocus). Finally, the third grating acts as a scanner to map out the interference pattern (Sciencefocus). "You don't know which of the slits the particle or wave function went through," Pedalino told Sciencefocus. "You have to assume it went through all of them, which makes up the interference pattern." The particles' journey through the device took 10 milliseconds (Sciencefocus). In that brief window, each cluster of 7,000 atoms existed in superposition at different locations spaced 133 nanometres apart (Yahoo, Nature). This spacing is more than 20 times the width of the nanoparticles themselves (Sciencefocus). To grasp the achievement, consider the scale. If you enlarged these clusters to the size of a ping-pong ball, the experiment would be equivalent to that ball being in two places around 80 centimetres apart simultaneously (Sciencefocus). Not a subatomic particle. Not a photon. A ping-pong ball, blurred across nearly a metre of space. The precision required was extraordinary. The rotation of the Earth had to be corrected for in the experiment (Sciencefocus). Any stray molecule, any vibration, any thermal fluctuation could destroy the delicate quantum state. The experiment took years to develop (Sciencefocus), and Pedalino spent "thousands of hours" in that basement laboratory before seeing results (Yahoo). ---

The Score That Shattered Records

Physicists measure quantum superposition using a metric called "macroscopicity," which accounts for both the mass of the object and the distance of separation. The sodium nanoparticles achieved a macroscopicity score of 15.5 (Newsbreak). This beat the previous record by an order of magnitude (Newsbreak), making it more than tenfold larger than any prior demonstration (Yahoo, Sciencefocus). To put this in perspective: in 2023, another team put a 16-microgram vibrating crystal into a superposition over a distance of two billionths of a nanometre (Yahoo). That experiment involved more mass but far less separation. The Vienna team achieved both significant mass, approximately 7,000 atoms per cluster, and substantial separation, 133 nanometres, simultaneously. "We've tested quantum mechanics again," Pedalino told Sciencefocus. The sodium nanoparticles exhibited wave-particle duality (Newsbreak), the signature behavior that defines the quantum realm. They set the record for the most macroscopic objects observed in quantum superposition (Newsbreak). Sandra Eibenberger-Arias, a physicist at the Fritz Haber Institute in Berlin, confirmed the significance. The results "show that, at least for clusters of this size, quantum mechanics is still valid," she told Nature. ---

The Boundary Problem

So why don't we see this in everyday life? Why can 7,000 atoms exist in two places at once, but a cat cannot? Two competing explanations dominate the debate. The first is decoherence, the process by which larger objects lose their quantum states through interaction with their surroundings (Sciencefocus). Every photon of light, every air molecule, every thermal vibration that touches an object causes it to "collapse" into a definite state. Objects eventually become too complex or interact too much to maintain a superposition through decoherence (Yahoo). Under this view, there's no hard boundary. Quantum mechanics remains universal. The equations never stop working. We just can't isolate large objects well enough to see their quantum behavior. The cat in Schrödinger's box would decohere almost instantly, its superposition destroyed by the trillions of particles surrounding it. The second explanation is more radical. Collapse theories suggest that beyond certain sizes or masses, quantum mechanics itself may break down (Sciencefocus). Something in the fabric of reality, perhaps gravity, perhaps something we haven't discovered, forces large objects into definite states regardless of isolation. In a 2025 Nature survey, 4% of researchers picked collapse theories as their favourite interpretation of quantum mechanics (Yahoo). The Vienna experiment doesn't resolve this debate. But it pushes the boundary further than ever before. More-massive particles have shorter wavelengths, making it harder to distinguish quantum predictions from classical ones (Yahoo). By demonstrating superposition at unprecedented scales, the team has narrowed the range where any collapse mechanism could operate. "There shouldn't be any fundamental limits from the basic theory," Pedalino told Sciencefocus. Standard quantum mechanics "never states it stops working above a certain mass or size," he explained to Nature. Giulia Rubino, a quantum physicist at the University of Bristol, UK, framed the challenge simply: "The only way to answer this question is by scaling up" (Yahoo). ---

The Road Ahead

The experiment opens the door for future experiments with biological materials like viruses or proteins (Newsbreak). Some viruses are a similar size to the clusters but tend to be more fragile (Yahoo). The team is working on putting biological matter through the experimental set-up (Yahoo). Imagine demonstrating that a virus, a structure capable of hijacking living cells, can exist in two places at once. The philosophical implications would be staggering. Where does life begin to obey classical physics? Does consciousness play any role? These questions, once confined to philosophy seminars, are becoming experimentally testable. The practical stakes are equally significant. Quantum computers will ultimately need to maintain perhaps millions of objects in a large quantum state to perform useful calculations (Nature). Understanding where and why superposition breaks down isn't just academic curiosity. It's engineering necessity. "If you ask a quantum physicist, we assume standard quantum mechanics is universal," Pedalino told Sciencefocus. The Vienna experiment supports that assumption. But the team knows they haven't found the boundary yet. They've only proven it lies further out than anyone had demonstrated before. ---

The Patience of Discovery

Science, at its best, is an exercise in structured patience. Sebastian Pedalino spent thousands of hours watching flat lines, adjusting parameters, eliminating sources of noise, waiting for reality to reveal itself. The experiment was conducted at 77 degrees kelvin in an ultra-high vacuum environment (Nature, Yahoo). Every variable had to be controlled. Every source of decoherence had to be eliminated or accounted for. When the waves finally appeared, they confirmed something Schrödinger found too strange to accept: the quantum world doesn't care about our intuitions. Clusters of 7,000 atoms, objects large enough to be seen under an electron microscope, can exist in multiple places simultaneously. The absurdity is real. The study was published January 21 in the journal Nature (Newsbreak), but the story began years earlier, in a basement laboratory where a physicist refused to give up on flat lines. The interferometer is two metres long (Sciencefocus). The vacuum chamber stretches six metres (Sciencefocus). The journey from beam to detector takes 10 milliseconds (Sciencefocus). But the journey from conception to confirmation took years of human persistence. We live in a universe stranger than its discoverers could accept. Schrödinger proposed his cat to mock quantum mechanics. Nearly a century later, physicists in Vienna have demonstrated that the mockery was misplaced. The cat, or at least its viral-sized cousin, really can be in two places at once. The question now is how far this strangeness extends. The Vienna team has pushed the boundary tenfold beyond previous records. They've shown that objects visible to microscopes obey the same equations as electrons. They've narrowed the gap between the quantum and classical worlds. But the gap remains. Somewhere between 7,000 atoms and a housecat, between 8 nanometres and the width of a whisker, the rules might change. Or they might not. The equations might hold all the way up, with only practical isolation preventing us from seeing quantum effects at human scales. The only way to find out is to keep scaling up. To build larger interferometers, isolate bigger objects, push the boundaries of what can be placed in superposition. The Vienna team has shown it can be done. The flat lines became waves. The impossible became a published result. Somewhere in a basement laboratory, the next experiment is already taking shape. The next two years of patience have begun.