Precession of the Equinoxes

A 25,920-year wobble the ancients tracked obsessively. The question is why they needed to.

Axial precession is measured astronomy (~25,772-year cycle, Hipparchus credited with discovery c. 130 BCE via star-catalog comparison). The contested layer is ancient knowledge: Santillana & von Dechend's 'Hamlet's Mill' (1969) argued world mythology encodes precessional numbers — a thesis academically marginal but never quite dismissed, given genuine numeric recurrences (72, 2160, 4320 in Babylonian, Indian, and Norse contexts). The node holds the real mechanism, the real Hipparchus question (what records let him see it?), and the mythological-encoding thesis, linking the Great Year and Orion-correlation files.