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Scientific Team Observes Time's Evolution in Lab 'Mini-Universe' of Ultra-Cold Atoms
Scientists have built a tiny "mini-universe" in a laboratory — and used it to measure time without a clock. A team at the University of Birmingham trapped 24,000 rubidium atoms, cooled them to billionths of a degree above absolute zero, and watched time "emerge" from the disorder inside the cloud itself. The results were published on June 12, 2026, in Physical Review Research.
Professor Giovanni Barontini led the experiment. He said that "in some theories of the universe, especially quantum gravity, time doesn't appear as a built-in feature" and that the study gives "the first experimental evidence that 'time' can be defined by internal changes," according to EurekAlert!.
A 43-Year-Old Idea Finally Tested in a Lab
The experiment builds on a 1983 theory by physicists Don Page and William Wootters. They proposed that time is not a fixed background — it "emerges" from quantum entanglement. Entanglement is when two particles are linked so that the state of one instantly affects the other. Their idea sat mostly untested for four decades, according to El Periódico.
In the 1960s, physicists John Wheeler and Bryce DeWitt tried to merge Einstein's theory of gravity with quantum mechanics. Their equation for the entire universe effectively "canceled out" time — suggesting a frozen, changeless cosmos. This became known as the "Problem of Time." Page and Wootters offered a fix: split the universe into two parts, entangle them, and time appears between them as a relationship.
How the Mini-Universe Simulates a Big Bang in 0.1 Seconds
Barontini's team split the atom cloud into two sectors: a "bright" part they could observe and a "dark" part that acted as the internal reference. Neither sector had an outside clock. Instead, the team tracked how disorder — called entropy — grew inside the bright sector. That growing disorder became their measure of time, according to La Brújula Verde.
The bright sector went through a full cycle of expansion and collapse — like a mini Big Bang followed by a Big Crunch — in just 0.1 seconds. The atoms had to be kept at nanokelvin temperatures, making the vacuum chamber one of the coldest spots in the known universe. This extreme cold lets quantum effects take over completely, per EurekAlert!.
Time as Disorder: What This Means for Physics
Theorist Alessandro Coppo of Italy's National Research Council had called time an "illusion" created by entanglement between a system and its clock. His 2024 work in Physical Review A built the math that made the 2026 experiment possible. The core idea: what we call "time passing" is just particles becoming more disorganized — entropy rising.
Experts say this is a key step toward a theory of "quantum gravity" — the long-sought bridge between Einstein's universe and the quantum world. By showing that time can be born inside a closed system, scientists now have a lab model for how the early universe worked before time itself existed, according to El Correo Gallego.
From GPS Clocks to Quantum Computers: Real-World Stakes
The findings could reshape technology far beyond the lab. Today's GPS systems rely on external atomic clocks that shift slightly due to gravity and motion. A "self-referential" time system — one that reads time from internal quantum states — could one day provide stable navigation where outside signals don't reach, such as deep space or underground.
Quantum computers also stand to benefit. Controlling how time emerges inside a quantum processor could help manage "decoherence" — the tendency of quantum bits to lose their information. Researchers say that mastering the internal "arrow of time" may be one key to keeping qubits stable long enough to be useful, per Levante EMV.
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