Extended Data Fig. 3: Binary collisions at the onset of the active gas.

(a) Snapshot of the system corresponding to the first binary collision (highlighted in green) after application of the electric field. (b) Close-up showing the trajectories of the two particles colliding in (a). Red circles indicate their initial positions. Orange circles and crosses indicate their positions at contact. After their super-elastic collision, the two particles move quickly away from each others. (c) Elevation of the two particles as a function of time reconstructed from stereo-imaging (t = 0 when the field is applied). Before they collide, the two particles oscillate in phase opposition.