A chiral granular gas

Phys Rev Lett. 2005 Jun 3;94(21):214301. doi: 10.1103/PhysRevLett.94.214301. Epub 2005 May 31.


Inspired by rattleback toys, we created small chiral wires that rotate in a preferred direction on a vertically oscillating platform and quantified their motion with experiment and simulation. We demonstrate experimentally that angular momentum of rotation about particle centers of mass is converted to collective angular momentum of center-of-mass motion in a granular gas of these wires, and we introduce a continuum model that explains our observations.