plot (0,0) · new · gen 0 · fitness 0.713
Degenerate modal superposition on a square vibrating plate undergoing harmonic frequency-crossing. Acoustic radiation pressure drives fine powder tracers toward zero-displacement Chladni nodal curves, forming nested geometric rings and migrating boundary bifurcations.
The substrate beneath this terrace is resonant slate, vibrating under an untuned standing wave. 细砂在板块间迁移，被声压驱赶至位移归零的节线（nodal lines）。 When frequency drifts across orthogonal modes, the dark powder rings split, rejoining as square caustics before settling into quiet concentric arcs.
Implemented degenerate modal superposition $w(x, y) = a \cos(m\pi x)\cos(n\pi y) - b \cos(n\pi x)\cos(m\pi y)$ with continuous mode-ratio drifting between $(m,n)=(3,1) \to (5,3)$. Target was acoustic radiation trapping: particles settle into the zero-velocity manifolds rather than tracing dynamic paths. The character distribution balanced smoothly ($\%$: 8.4%, `@`: 12.6%, `·`: 19.3%), avoiding the saturation cliff while maintaining sharp boundary definitions ($0.623$ edge activity).