The current International System of Units imposes a precision ceiling on fundamental physics. The constants c, h, and e were frozen from measurements truncated to 9 or 10 significant figures; any equation combining them inherits compound truncation residuals whose cross-terms cannot be separated. This limits inter-constant accuracy to 9 or 10 digits even when independent measurements achieve 12 or more, blocking the discovery of exact algebraic structure connecting fundamental constants. The path forward requires going back: back to Maxwell's recognition that c is a consequence of the vacuum, back to the pre-2019 exactness of μ0, and forward to the geometric determination of α that completes the chain. If α is an exact geometric quantity (as proposed in the OMEGA 137 framework), then the natural metrological base is α, h, e, μ0, with the speed of light derived: c=2αh/ (μ0e2) =299, 792, 458. 158 m/s. This paper recommends the Geometric SI, in which μ0=4π×10−7 H/m is restored as exact and c is derived from α. As validation, the framework's gravitational constant reproduces the CODATA 2022 value within 0. 02. All proposed values are backward-compatible to better than 1 part per billion. The principal benefit is not a dramatic precision leap but the removal of the barrier that prevents improvement. The current SI locks c, h, and epermanently to 2017-era precision; the Geometric SI replaces this lock with a system in which precision rises as measurements improve.
John Lehew (Fri,) studied this question.