Complex patterns emerging from ball drops on semicircle

Ball drops on semicircle revisited, and explained visually. The final phase spaces, colored by gap do perhaps need better explanations in text though. Here the ball starts at a position on the semicircle boundary in a specific direction with a velocity bounded by the maximal potential energy (horizontal line in the left panel). Another infinitesimally separated ball (not shown, effectively on the same pixels as the first ball) will separate from the first ball at a certain rate. The color of the right panel displays the distance between the balls: yellow = fast (exponentially = chaos), blue = slow (typically non-exponentially = calm). Music by ‪@gpcbass‬, called How Winds, originally made by him 1977. Languages/tools: Python, WebGL, Opus 5.5, FFmpeg