Chladni: Sound Patterns

In the 18th century the physicist Ernst Chladni drew a bow across a metal plate scattered with sand, and the sand arranged itself into a pattern. When a plate vibrates, certain lines stay perfectly still. The sand settles along those quiet lines, and the pattern appears. These are Chladni figures. This app recreates that phenomenon in the palm of your hand. Three thousand grains tremble on the screen and slowly gather along the nodal lines. It is made for watching that settling happen. What you can do - Four plates, twenty patterns: switch between square, circle, triangle and ring plates. Each has five patterns, twenty in all. Every plate has its own sand colours and its own range of tones. - Turn the dial: rotating the dial changes the pattern. The sand is not reset. It slowly rearranges itself from the shape it is in into the new one, and that rearrangement is the part worth watching. - Hear the tone: each pattern has its own pitch, and the range of tones moves with the plate you choose. Turn the sound off whenever you want to watch in silence. - Sing to the sand: turn on the microphone and hum a clear, steady note. The pitch of your voice selects a pattern within the current plate, and the volume sets how wildly the sand dances. Your voice is analysed on the device as it happens. Nothing is recorded and nothing is sent anywhere. - Fill the collection: save the patterns you like with a name of your own. The collection has twenty slots, and each saved pattern is given one to three stars according to how intricate it is. Mark favourites and filter to show only those. Tap a saved pattern to bring it back to the screen. - Export a wallpaper: save the current pattern as a 1179 x 2556 PNG in your Photos. It is not a snapshot of the screen. Grains of sand are redrawn along the nodal lines computed from the equations, so the sandy texture holds up at full resolution. The mathematics is computed, not drawn The circular plate uses Bessel functions and the triangle uses the exact Lame solution, and so on for each shape. Nothing is a prepared picture being played back. Every pattern comes from an equation solved on the spot. Free, and what the one-time purchase adds Watching, switching plates, sound, microphone mode, the collection and favourites are all free. Exporting a wallpaper is free too, but while the app is free the exported image carries a faint watermark of the app name. A single one-time purchase removes that watermark from the wallpapers you export. It is the only thing for sale and it is not a subscription. Without it you can still watch every pattern, fill the whole collection, and save wallpapers. For your peace of mind - No ads - No tracking - No account required - Works offline (it connects only to buy or restore the one-time purchase) - Your collection is stored only on this device - Your voice is only analysed, never recorded or transmitted - Available in Japanese and English Take a moment and watch the pattern rise quietly out of the sand.