Chladni figures: sand vibrating on a metal plate

https://www.youtube.com/watch?v=wvJAgrUBF4w

In the attached video, sand gathers at the nodal set of a vibrating metal plate to create incredible patterns called Chladni figures. The resonance of a metal plate is described by a biharmonic operator with free boundary conditions, and the nodal set at a given input frequency is the zero set of an eigenvector of that biharmonic operator. In this talk, I'll hop, jump, and skip my way to simulating these figures.