The tiny machines inside your living cells actually work in a way that breaks the flow of time.
arXiv · March 18, 2026 · 2603.16517
The Takeaway
While fundamental physics equations usually work the same forward and backward, life requires a specific direction. Researchers found that a cell's internal scaffolding actively creates a 'one-way street' for motion, providing a measurable physical basis for the arrow of time inside a living organism.
From the abstract
We investigate signatures of broken time reversal symmetry in stochastic trajectory data, employing the previously introduced three point correlation called mean back relaxation. We specifically investigate data from a simple driven model, as well as from colloidal particles within living or passivated biological cells. Both in the model as well as in cell data, MBR detects broken time reversal symmetry, and furthermore, allows to determine relevant time and length scales of activity. For the ce