The disorder of a head against its divergence angle, 300 points

μ₂ is the mean squared departure of a Voronoi cell's side count from six, measured on 300 points inside 86% of the radius. Swept across 1.60° it is a staircase: flat over stretches of a few hundredths of a degree, with sharp steps between them and narrow deep dips wherever a rational falls. At 137.144° — which is 360 × 8/21 — it is 0.078; At 137.648° — which is 360 × 13/34 — it is 0.197; At 138.460° — which is 360 × 5/13 — it is 0.060. The ticks along the top are the fractions p/q, placed from arithmetic rather than from the curve.