Cymatics is the study of visible sound and vibration, named from the Greek "kyma" (wave). In 1787 the German
physicist and musician Ernst Chladni popularized the technique now called Chladni plate experiments: a flat
metal plate is covered with fine sand or salt and bowed or driven with a speaker at a specific frequency. The
plate vibrates in complex modes with regions that move a great deal (antinodes) and regions that barely move at
all (nodal lines). Loose particles are flung away from the antinodes and settle along the still nodal lines,
tracing out intricate symmetric patterns. As driving frequency increases, the wavelength shortens and the plate
supports higher-order vibration modes, so the nodal patterns become progressively more complex with more
subdivisions. This simulation approximates that behavior with interfering radiating wave sources plus a
standing-wave mode term, colored by local displacement amplitude the way sand density would reveal nodal lines
on a real plate.
- Ernst Chladni first published his sand-pattern plate experiments in 1787, earning him the nickname "father of acoustics"
- Sand and salt collect at nodal lines, where the plate's vertical displacement is at or near zero at all times
- Higher driving frequencies produce shorter wavelengths, exciting higher-order modes with more nodal lines and finer pattern detail
- Human hearing spans roughly 20 Hz to 20,000 Hz; classic classroom Chladni demonstrations typically use 20 Hz-2 kHz for visible plate patterns
- Standing-wave (Chladni) mode shapes are described by two integer mode numbers, analogous to modeN and modeM in this simulation
- Modern researchers use cymatic and Chladni-plate techniques to study acoustic resonance in violin and guitar soundboards, loudspeaker cones, and MEMS devices
- The pattern's symmetry directly mirrors the plate's boundary shape and material stiffness, which is why square, circular, and free-edge plates each produce distinct families of patterns
- Interference from multiple simultaneous sources (as used here) creates additional beating and moiré-like patterns beyond a single-frequency Chladni figure