Onset of Shear Waves In A Bacterial Bath: A Novel Effect

TL;DR

This paper predicts the emergence of shear waves in bacterial baths due to bacterial swirl formations, suggesting a new physical phenomenon that can be experimentally tested.

Contribution

It introduces a novel effect of shear wave propagation in bacterial baths caused by bacterial structural ordering, not previously documented.

Findings

Shear waves can propagate in bacterial baths at the scale of bacterial swirls.

Structural ordering in bacterial baths influences their mechanical response.

The predicted effect is testable in future experiments.

Abstract

Recent experiments on particle diffusion in bacterial baths indicate the formation of correlated structures in the form of bacterial swirls. Here we predict that such a structural ordering would give rise to the new effect of propagating shear waves in a bacterial bath at length scales of the order of a swirl, which corresponds to time scales of the order of the lifetime of a swirl. Our prediction can be tested against future experiments in bacterial baths.