Cymatics are visual patterns that combine three ingredients: thin plate, a pinch of loose material, like sand or salt, and a heavy dose of music.
The particles that the wave is moving through are vibrating in the same direction as the wave itself. The particles move back and forth so that there are some areas of compression, where all the particles have moved really close to one another, and some areas of expansion, where all the particles have moved away from one another.
And a heavy dose of music.
