If you’ve never seen a Chladni plate in action before, prepare to be amazed by the beauty of simple physics.
Named for physicist Ernst Chladni, a Chladni plate is a thin, metal, centrally-mounted rectangular plate—nothing extraordinary. But when a particulate substance like sand, salt, or in this case, couscous is scattered across its surface, and its side is struck with a bow, the substance distributes itself across the plate in precise geometric patterns.
These patterns are called Chladni figures, and though Ernst Chladni discovered them, it took mathematician Sophie Germain to determine why the patterns took shape the way they did. It has to do with the wave dynamics of the plate’s vibrations when it’s “played” by the bow. Certain parts of the plate remain stable and don’t vibrate, and these are the areas where the grains migrate. Different ways of striking the plate produce different vibrations and different Chladni figures. It’s a simple principle, but fascinating to watch.
Naturally, being a female mathematician in the early 19th century meant Germain’s work went totally unrecognized until after her death, when Carl Friedrich Gauss campaigned for her to receive an honorary degree.
Watch on to see science presenter Steve Mould demonstrate some of the possible Chladni figures, and marvel at some aesthetically satisfying mathematics.