Structural Variation and the Phenomenology of Physical Constants

Persistent anomalies in measurements of fundamental physical constants—including the Hubble tension, fine-structure constant anisotropy, and gravitational constant scatter—suggest spatial dependence beyond standard models. This work proposes a phenomenological framework in which observables acquire position-dependent corrections governed by a scalar structural field via the Structural Law. The framework preserves Lorentz invariance and permits only spatial structural variation. Anomalies across cosmology, particle physics, and astrophysics are shown to be quantitatively consistent with this model. Falsifiable predictions are presented. A discrete-spacetime realization (QuEST) illustrates the microphysical origin of the structural field, though the law remains agnostic to its derivation.