Bubble Organ

Side view, to scale (bubbles drawn twice their size): the row of nozzles on the bottom, low notes on the left, and the bubbles rising at their terminal speed, coloured by pitch and glowing while they ring. ◉ the two hydrophones you listen through, 35 cm in front of the row.

The pressure the engine computed for the last bubble released (one hydrophone’s share, in pascals), and the model’s decay envelope e^−bt (dashed). Its pitch and damping δ = 1/Q, split into heat flow, radiation and viscosity.

Devin’s damping constants for every key’s bubble under the current settings (log scale), and the gas’s effective polytropic exponent κ, between 1 (isothermal) and γ (adiabatic).

A bubble rings at one frequency: no overtones. A held key’s brook smears its line by the size spread.

Every bubble is a short blip at a single frequency, its Minnaert ring; a held key's brook is a stream of them, spread a little in pitch by the bubbles' sizes.