A Precise Geometric Derivation of the Proton–Electron Mass Ratio from Closure Constraints in Space–Change Geometry, without Free Parameters

Why is the proton approximately 1836.15 times more massive than the electron? Despite extraordinary experimental precision, this dimensionless ratio has no accepted theoretical explanation. This paper derives the proton–electron mass ratio directly, with relative agreement to the CODATA 2022 value at the 10^-11 level. The derivation arises from geometric closure constraints as formulated in Space–Change Geometry, without introducing free parameters or fitted coefficients.