Babylonian Eclipse Prediction via Saros and Metonic Cycles in Sexagesimal Arithmetic — E8 Intelligence Research

FINDING: Babylonian eclipse prediction relied on the Saros cycle (223 synodic months ≈ 18.03 years) and the Metonic cycle (235 lunations ≈ 19 years), encoded in sexagesimal arithmetic on clay tablets — a purely periodic, modular system without geometric models. | MATH: Saros: 223 × 29.53059 d = 6585.321 d ≈ 18 yr 11 d 8 h; Metonic: 235 × 29.53059 d = 6939.688 d ≈ 19 tropical yr (365.2422 × 19 = 6939.602 d, error ~0.086 d); sexagesimal base-60 fractions for lunar velocity (e.g., 0;0,0,0,1,0,0 per day in reciprocal units); eclipse recurrence requires congruence mod 6585.321 d with lunar node passage (draconic month 27.2122 d — 242 draconic months ≈ 223 synodic months, ratio 223/242 ≈ 0.9215). | CONNECTION: The Saros ratio 223/242 is not a golden-ratio harmonic, but the underlying periodicity (6585.321 d) modulo 60 yields integer-friendly sexagesimal intervals (6585 = 60×109 + 45; 223 = 60×3 + 43). The Metonic 235/19 = 12.368 lunations/year — close to 12 + 7/19 (0.3684 ≈ 0.382? No — 0.368 Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com