For nearly sixty years, one of the deepest puzzles in physics has been hiding in plain sight: the equations that describe the universe at its most fundamental level have no time in them. The Wheeler-DeWitt equation, a cornerstone of quantum gravity, describes the cosmos as a static, unchanging quantum state—a picture in which the familiar flow of past to future simply does not exist. Yet we experience time. We age. We remember. We wait. So where does it come from? In 2026, a physicist at the University of Birmingham may have finally built an experiment that answers that question—not by finding a cosmic clock, but by creating a tiny universe in which time begins on its own.
The experiment is the work of Professor Giovanni Barontini, and it is deceptively simple in its design. Barontini took a cloud of 24,000 ultracold atoms—cooled to just a few billionths of a degree above absolute zero—and trapped them in an isolated quantum system. He then used two laser beams to create a thin barrier, dividing the cloud into two regions: a “bright” sector that could be observed, and a “dark” sector that was deliberately hidden from view. Inside this sealed miniature cosmos, the bright region repeatedly expanded and contracted, mimicking the theoretical cycles of a Big Bang followed by a Big Crunch—the hypothetical scenario in which the universe’s expansion eventually reverses.
The crucial move was what came next. Instead of measuring the sequence of events with an external laboratory clock, Barontini asked whether the mini-universe could keep track of its own time. He built what he called “entropic time”—a clock that measures the flow of disorder, or entropy, between the bright and dark sectors. As atoms moved across the barrier, the distribution of matter changed, and that change provided a consistent, one-way sequence of events. Time, in other words, emerged from the internal dynamics of the system itself.
The results were striking. The entropic time flowed in a consistent direction, giving a clear “arrow of time” even as the mini-universe expanded and contracted. It correctly ordered events. And remarkably, it sped up, slowed down, and even stopped depending on what the atoms were doing. When atoms moved rapidly across the barrier, time “sped up.” When the flow slowed, time “slowed.” When the atoms stood still, time stood still. “Time was speeding up or slowing down, or even stopping, depending on what the system was doing,” Barontini told Live Science.
The experiment also offered a clue about why time has a direction at all. When Barontini deliberately chose not to observe the dark sector, he gave up information about that half of the system. That ignorance, measured as entropy, is precisely what created the flow of time in the observable half. Time, in this picture, is not a fundamental ingredient of reality. It is a consequence of what an observer chooses to ignore.
The implications are significant. This is the first controlled experimental evidence that time can be defined by changes within a system rather than by an external ticking clock. It provides a laboratory testbed for ideas in quantum cosmology and quantum gravity that have long remained purely theoretical, allowing physicists to study the nature of time in a tabletop experiment. Barontini even showed that a version of the Schrödinger equation—the central equation of quantum mechanics—can be rewritten using entropic time, preserving the theory’s predictive power while removing the need for an external time parameter.
But does this mean scientists have discovered how time begins? The honest answer is: not exactly. The experiment does not explain the absolute origin of time—the moment of the Big Bang itself, or why there is something rather than nothing. What it does show is how a sense of time can arise from within a system that has no built-in clock. It demonstrates that time is not necessarily a fundamental feature of the universe, but can be an emergent property of the relationships between things. As Barontini put it, the study “provides the first controlled experimental evidence that ‘time’ can be defined by changes within a system rather than as the external ‘ticking clock’ we think of as time”.
That is a profound shift in perspective. For decades, the problem of time in quantum gravity has been a theoretical cul-de-sac—a puzzle that seemed to require a complete theory of everything to resolve. Barontini’s mini-universe has transformed it into an experimental question. The next step will be to refine the model, to study how gravity might fit into the picture, and to explore whether the entropic time observed in a cloud of ultracold atoms has anything to say about the time we experience in the macroscopic world.
The philosophical implications are equally striking. If time is not fundamental but emergent, then the universe at its deepest level may be a static, timeless quantum state. The flow of time we experience—the sense that the past is fixed and the future is open—would then be a kind of illusion, a byproduct of our limited perspective as observers who cannot see the whole system. That idea is not new; it has been floated by physicists for decades. But until now, it has never been tested in a controlled laboratory experiment.
Barontini’s tiny universe does not settle the question. It does not prove that time is an illusion, nor does it explain why the universe exists at all. But it does something almost as important: it brings one of the deepest mysteries of physics down to earth. It shows that the origin of time can be studied not just with equations and thought experiments, but with lasers and atoms and a cloud of ultracold gas. And in doing so, it opens a new window onto the question that has haunted philosophers and physicists for millennia: what is time, and where does it come from?
The answer, it seems, may be stranger than we imagined. Time may not be a river flowing from past to future. It may be a pattern that emerges from the way things change—a pattern that can be created, controlled, and studied in a laboratory. And if that is true, then the universe we inhabit may be far more mysterious, and far more wonderful, than the ticking clock on the wall suggests.
