Illustration from Scientific Research

We let all scatterers move freely under time-dependent external perturbations and wish to control the trajectory of the orange ball, guiding it on a sinusoidal path. The blue balls have a metallic nut glued to them, allowing us to randomize their motion by applying fast magnetic perturbations with a moving external electromagnet. They are loosely anchored to the ground by strings to avoid colliding with the orange ball.

DOI