Chances are you’ve seen the gorgeous patterns that sound waves produce when sand is sprinkled on a vibrating metal plate. Now French physicists have produced inverse versions of these patterns using microbeads suspended in a liquid. They described their work in a recent paper in Physical Review Letters.
The original patterns are known as Chladni figures, after the late 18th century acoustics pioneer Ernst Chladni. Inspired by Robert Hooke’s experiments over a century earlier, Chladni sprinkled sand over a solid metal plate, and then ran a violin bow along the edge to make it vibrate. As if by magic, the grains of sand rearranged themselves into patterns corresponding to various frequencies. But it’s actually due to some intricate (and intriguing) physics, as Diana Cowern, a.k.a. the Physics Girl, explains with her own DIY demonstration:
source: gizmodo.com by Jennifer Ouellette