Physicists observe 'entropic time' in lab simulation: study examines time emergence without external clocks

Physicists have long struggled to reconcile quantum mechanics with gravity. Professor Giovanni Barontini shifted the focus to laboratory-scale quantum systems. His experiment aims to bridge the gap between theoretical quantum gravity and observable physical phenomena. Barontini developed a method to track time. He measures changes in how atoms distribute within a miniature universe.

1. Professor Giovanni Barontini and his team at the University of Birmingham created a miniature universe using 24,000 atoms. The researchers cooled these atoms to temperatures a few billionths of a degree above absolute zero to isolate the system.

2. Researchers published their findings in the journal Physical Review Research. The team used two laser beams to split an atom cloud into bright and dark regions. This method allowed them to track particle distribution.

3. The experiment demonstrates that entropic time establishes a consistent arrow of time within the system.

4. Barontini demonstrated that the Schrödinger equation, a quantum mechanics staple, can be expressed using entropic time.

1. The miniature universe is a mathematical simulation rather than a real gravitational system. Researchers used Rubidium-87 atoms in a magnetic trap to mimic cosmic expansion, meaning the setup lacks actual gravity or curved spacetime.

2. Total entropy across the entire 24,000-atom system remained constant during the experiment. The arrow of time only appeared in the bright region because the hidden dark region acted as a reservoir to absorb and release particles.

3. The system experienced brief reversals in the direction of time during testing. Imperfections in tracking the atom cloud caused the internal clock to temporarily tick backward, and the mathematical model breaks down at the simulated Big Bang and Big Crunch points.

4. The modified Schrödinger equation relies on simplified mathematical approximations to work. Researchers had to estimate average atom densities and assume slow, idealized conditions rather than calculating exact quantum interactions.