Lab-made 24,000-atom cosmos hints time can emerge from entropy
Researchers built a sealed, two-region quantum system of 24,000 ultracold rubidium atoms that behaves like a tiny universe, cycling between expansion and contraction without any external clock. Time appears to flow from internal changes in entropy (entropic time), allowing the sequence of events to be inferred from within the system and offering a controllable testbed for ideas in quantum gravity and early-universe physics. The study also shows Schrödinger dynamics can be reformulated under this time concept and could help probe fundamental questions about the origin of time.