Chladni plate

• Chladni's plate

Named after their inventor, German scientist Ernst Florens Friedrich Chladni.

Chladni plate (plural Chladni plates)

1. A flat sheet of metal (generally square or circular) mounted on a central pillar, over which sand or other particles are sprinkled, which when bowed vibrates and arranges the sand particles into patterns (Chladni figures), allowing for the visualization, and analysis, of sound.
   • 1909, Benjamin Warner Snow, Notes on Physics, page 579:

     […] the phenomenon of forced, or sympathetic, vibrations may be beautifully shown by having two Chladni plates exactly alike, and setting one in vibration by bowing. The sand will gather along the nodal lines, showing that vibrations of a certain character exists upon the plate. If, now, sand is scattered upon the second plate, and this is held near the first, the second will be thrown into vibrations similar to the first, […] as will be shown by the sand pattern upon the second appearing identical with that on the first.

   • 2013, Eric J. Heller, Why You Hear what You Hear: An Experiential Approach to Sound, Music, and Psychoacoustics, Princeton University Press, →ISBN, page 297:

     Why should a Chladni plate, possessing many inharmonic mode frequences, set up a cooperative resonance when bowed? How sticking and slipping works with a bow and a Chladni plate is not so clear, since in the pure sinusoidal mode there is no sawtooth Helmholtz kink wave to follow the bow in the sticking phrase and jerk away suddenly in the slip phase. The bowing of a Chladni plate is tricky to do, […] Once a Chladni plate is sent to singing at a given frequency and nodal pattern, it will set a nearby identical plate into the same pattern […]