The HOH Bond Angle as a Temperature-Dependent Phase Parameter

The HOH bond angle in water — 109.5° (tetrahedral ideal), 105° (at 4°C), and 104.5° (liquid at room temperature) — is conventionally explained via sp³ hybridisation and lone-pair repulsion. These descriptions are accurate but provide no mechanical cause. Within the framework of Push-theory (SOTW), we demonstrate that the HOH angle is not a fixed molecular property but a temperature-dependent phase parameter governed by the tetrahedral geometry of the electron’s 4-loop Flux-Pump, the six degrees of freedom of hydrogen resonance, and the Venturi suction of the 8-Möbius proton. The 4°C density maximum of water emerges as the exact temperature at which one flux-rib of the tetrahedral electron collapses, transitioning the structure from open tetrahedral lock (109.5°) to laminar maximum packing (105°). The room-temperature value of 104.5° reflects thermally-induced flux friction reducing the Venturi suction slightly further. This paper presents a unified mechanical derivation of all three observed HOH angles from three axioms and no free parameters.