A Planck-Normalized Physical-Vacuum Response Model for Newtonian Weak-Field Gravity

Newtonian gravity is firmly established in the weak-field regime, but its deeper physical origin remains an open question. To address this question, we develop a minimal effective construction on fixed Minkowski spacetime in which matter is represented by localized oscillatory defects of dynamical vacuum fields, with complete background-subtracted energy determining rest mass and inertia. Gravity arises from a source-induced deficit in the first angular moment of an otherwise isotropic vacuum response. Captured energy is restored through statistically isotropic backgroundization, while the source-test directional correlation is not restored in the ideal limit. Separate source and test responses, together with reciprocity and universal response per unit complete mass, yield an inverse-square interaction and composition-independent free fall. A Planck-scale normalization recovers the Newtonian coupling and the Poisson equation under linear superposition. Because the Planck scales already contain the measured gravitational constant, this construction provides a factorization and physical reinterpretation of Newtonian gravity rather than an independent prediction of G. A distinct collective vacuum-momentum response for extended many-defect systems is also outlined, while its normalization and astrophysical applications are left to future work.