A Chladni plate simulator built on real physics

Sand on a vibrating metal plate gathers into figures. Here’s what a real 24 cm aluminium plate draws from 60 to 1,300 Hz, and the live simulator that drew these pictures.

Open the live plate

Free in the Lab. Pick any frequency, square or round, and change the plate’s thickness.

How a Chladni plate works

MeasuredErnst Chladni showed it in 1787: draw a violin bow along the edge of a sand-covered metal plate, and the sand jumps off the parts that shake and settles along the lines that stay still, the nodal lines^[1]. Each resonance of the plate has its own figure, and higher frequencies make busier figures with more lines.

From 60 to 1,300 Hz on one plate

All of these are the same plate: aluminium, 24 cm square, 0.75 mm thick, bolted at its centre to a shaker.

Sand figure on the square plate at 60 Hz — **60 Hz** · resonance 62 Hz

Sand figure on the square plate at 120 Hz — **120 Hz** · resonance 115 Hz

Sand figure on the square plate at 200 Hz — **200 Hz** · resonance 219 Hz

Sand figure on the square plate at 300 Hz — **300 Hz** · resonance 321 Hz

Sand figure on the square plate at 650 Hz — **650 Hz**

Sand figure on the square plate at 900 Hz — **900 Hz** · resonance 928 Hz

Sand figure on the square plate at 1300 Hz — **1300 Hz** · resonance 1273 Hz

The same plate in a round version, 24 cm across:

Sand figure on a round plate at 300 Hz: one large ring and a small ring in the centre — **300 Hz** · round

Sand figure on a round plate at 900 Hz: two rings and a small centre ring — **900 Hz** · round

Real physics, not a pattern generator

MeasuredMany online cymatics tools draw a textbook formula, or stretch a fixed set of patterns to whatever frequency you type. This one calculates the resonances of an actual plate, the same kind of setup as the UC Santa Cruz physics demo: an aluminium plate bolted at its centre to a vibrator^[2]. The calculations match NASA’s standard tables for a free square plate (Leissa, NASA SP-160)^[3], and the figures follow the same order as published university lab charts.

One thing it shows that most videos don’t: the same frequency draws different figures on different plates. Make the plate thicker and every resonance moves. Swap the aluminium for steel, glass or ceramic and you get the same figures, in the same order, at slightly different notes. That’s why claims about the “shape” of a frequency, like 432 Hz or 528 Hz, depend entirely on the plate.

Try a real one

A real plate is cheap to set up: a thin metal plate bolted at its centre to a speaker or a mechanical shaker, a tone generator, and fine sand or salt. Coarse grains gather on the still lines. Very fine powder can collect where the plate moves most instead, as Chladni noticed and Michael Faraday studied in 1831^[4].

Questions

What is cymatics?

Cymatics is the study of patterns made visible by vibration, like sand on a plate or ripples on water. Chladni plates are the classic example.

Why does the pattern change with frequency?

Each figure belongs to one of the plate’s resonances. Higher resonances bend the plate into more pieces, so the sand draws more lines.

Does the figure depend on the plate?

Completely. Size, thickness, material and how the plate is held all move the resonances. The same tone can draw a cross on one plate and rings on another.

Sources

Chladni EFF. Entdeckungen über die Theorie des Klanges. Leipzig (1787). Public domain.
UC Santa Cruz Physics Demonstrations. Chladni figures. ucscphysicsdemo.sites.ucsc.edu
Leissa AW. Vibration of Plates. NASA SP-160 (1969). ntrs.nasa.gov/citations/19700009156
Faraday M. On a peculiar class of acoustical figures. Philosophical Transactions of the Royal Society 121:299–340 (1831). doi:10.1098/rstl.1831.0018

More sound guides

432 HzHear it next to 440, and see what it draws on a real plate.528 HzThe “love frequency”: the claims, the tests, the plate.Brown noiseDeep, rumbly noise with a sleep timer. Brown vs pink vs white.