Change the note, and sand on a vibrating metal plate forms a different geometric pattern. The grains bounce away from parts moving strongly and gather along lines that barely move.

These patterns, called Chladni figures, vary with the plate’s shape, how it is supported and the vibration mode excited. They make the plate’s otherwise hard-to-see motion visible.

Sound that draws patterns in sand

Sound on: grains form Chladni figures as the vibration frequency changes — Saint Mary’s University Physics (SMUPhysics). Original Chladni plate demonstration; watermark retained.

Different resonant frequencies produce different sand patterns on a square plate — University of Colorado Boulder, Physics Undergraduate Labs. Original Chladni demonstration photographs.

Actual demonstration footage of grains rearranging into a new pattern — Saint Mary’s University Physics (SMUPhysics). Original Chladni plate demonstration; watermark retained.

Sound that draws patterns in sand

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