From a given moment, time’s arrow might have shot off in the opposing direction. “The physics is actually telling us that the opposite direction might have been equally possible,” Rocco says.

Schematic showing the concept behind the time-reversal transformation. The system and environment move backward in time. Credit: Scientific Reports (2025). DOI: 10.1038/s41598-025-87323-x ...

This challenges the idea that time only moves in one direction. ... Nov. 26, 2021 — A team of physicists has shown how quantum systems can simultaneously evolve along two opposite time arrows ...

Imagine that instead of flowing in one direction – from past to future – time could flow forward or backward due to processes taking place at the quantum level.