Open Veils · Answer
Why don't columnar basalts form perfect hexagons?
Perfect hexagons never form because lava doesn't have infinite time to self-correct. The 'six' is a thermodynamic attractor — a target the system perpetually hunts but rarely reaches. The real story is in the maturation dynamics: a living, self-correcting crack network racing against solidification, and the geometry of that race is far stranger than textbooks admit.
Evidence
- According to Budkewitsch and Robin (1994), the surface of a cooling lava flow initiates cracking in a chaotic rush — producing T-type and X-type quadruple junctions, curved lines, and wildly irregular polygons.
- Their VOPONUCE algorithm models what happens next: each propagating crack must follow the steepest thermal gradient, meaning it tracks the hottest nearby point — invariably the centre of an adjacent, larger column.
- This creates a feedback loop in which crack boundaries continuously renegotiate territory between unequal columns, functioning as a natural shape-corrector.
- Mathematically, when this process drives all junctions from T-type to Y-type triple junctions, the average polygon count is forced to exactly six — not by design, but as a topological inevitability.
- (2012), across 50 field sites, measured a mean of only 5.71 sides per column.