Can 960 Mixed-Up Balls Become a Perfect Rainbow? | 12 Satisfying Simulations, No Talking

About this piece

Sixty waves of sixteen shuffled balls run through a sixteen-lane sorting network. Every comparator that finds a pair in the wrong order swaps it, and the balls land in a panel on the right until all 960 sit in sixteen colour bands. Then eleven more pictures finish themselves: a vault that opens after 670 clicks, a coral ring that outlives its island, a record cut in one 520-metre groove, a wind that sorts 1,200 grains by weight, a wall of cubes that turns into a heart, and rockets that learn to fly around a barrier.

The number under each chapter title is the simulation's own count in that frame: balls landed, clicks of the vault, corals grown, cube turns, rocket hits, metres of groove, grains in the pits, contour lines, litres sprayed, digits of pi, wheel rolls and minutes of falling.

How the sort works: the network is Batcher's odd-even merge sort for 16 lanes, 10 layers and 63 comparators, checked on all 65,536 inputs of zeros and ones, so every wave comes out in order. The winnowing chapter gives each of the six grain kinds its own drag, solved so that each kind lands in the middle of its own pit. In the tunnel chapter every straight tunnel through a uniform Earth takes the same 42 minutes, whatever its length, so all nine balls arrive together. The square wheels roll level on a road of inverted catenary humps whose arc length equals one side of the wheel. The rockets use a genetic algorithm: each generation keeps the best flights and mixes and mutates the rest, and the last flight copies a rocket that already reached the target. The vault, the fountain, the record, the atoll and the cube wall follow fixed plans so that each picture finishes on time. The rules, the code and the sound are all original.