Overview
- The University of Birmingham team, which published their paper on June 11, created a hermetically sealed cloud of 24,000 ultracold rubidium atoms that acted as a tiny isolated ‘universe’.
- A laser‑made thin barrier split the system into an observable ‘bright’ region and an unobserved ‘dark’ region so researchers could track internal changes without using an external clock.
- Researchers found a consistent arrow and ordering of events driven by changes in entropy — a notion they call ‘entropic time’ that can speed up, slow down, or halt when particle distributions stop changing.
- The team reformulated a Schrödinger‑type description using entropic time to show standard quantum predictions still hold in this internal‑time framework, and they published the results in Physical Review Research.
- The setup gives physicists a new, controllable platform to test ideas from quantum cosmology and quantum gravity, though scaling the system and linking it to real black holes or the early universe remain future work.