In 1787 German physicist Ernst Chladni popularized these figures by drawing a violin bow across the edge of a metal plate sprinkled with sand. Sand grains bounce away from antinodes — regions of maximum vibration — and settle along nodal lines where displacement is zero, revealing the plate's resonant standing-wave mode shape. Different (m, n) mode numbers and driving frequencies produce distinct symmetric geometric patterns, and higher frequencies generally yield more complex patterns with more nodal lines. The technique is still used to tune violin and guitar soundboards, and it inspired Hans Jenny's field of cymatics, the visual study of wave phenomena. Drag to orbit, scroll to zoom.