Noisy active matter

TL;DR

This paper reviews how noise, traditionally seen as randomness, actually acts as a crucial resource for order, adaptation, and emergent behavior in biological and engineered active matter systems across scales.

Contribution

It offers a unified perspective on noise as a resource, connecting phenomena from molecular to collective scales in active matter systems.

Findings

Noise enables symmetry breaking and decision-making in active systems.

Energy feedback rectifies stochastic fluctuations to produce order.

Multiplicative noise drives pattern formation and state transitions.

Abstract

Noise threads every scale of the natural world. Once dismissed as mere background hiss, it is now recognized as both a currency of information and a source of order in systems driven far from equilibrium. From nanometer-scale motor proteins to meter-scale bird flocks, active collectives harness noise to break symmetry, explore decision landscapes, and poise themselves at the cusp where sensitivity and robustness coexist. We review the physics that underpins this paradox: how energy-consuming feedback rectifies stochastic fluctuations, how multiplicative noise seeds patterns and state transitions, and how living ensembles average the residual errors. Bridging single-molecule calorimetry, critical flocking, and robophysical swarms, we propose a unified view in which noise is not background blur but a tunable resource for adaptation and emergent order in biology and engineered active matter.