The odd flows of a colloidal chiral fluid*

We report the assembly of a chiral fluid composed of millions of spinning colloidal magnets. By activating the fluid at the single unit level, we observe macroscopic flows with no counterpart in conventional fluids. Odd viscous stresses drive the propagation of unidirectional free-surface waves damped by odd (or Hall) viscosity. Further, the competition between odd stress and cohesive forces results in intermittent bulk flows, blurring the distinction between solid and liquid.