Electromagnetic Confinement-Based Nuclear Radius Formula

We present a physically motivated formula for estimating the nuclear radius based solely on fundamental constants. The model derives the nuclear radius as a scaled projection of an electromagnetic confinement limit—defined as the minimum spatial curvature radius spacetime can sustain for electromagnetic energy. By combining the Bohr radius (as anatomic-scale reference), the fine-structure constant (as a measure of EM field strength), and geometric scaling 1/3 with proton number Z, we obtain a compact expression that predicts nuclear sizes with reasonable accuracy across the periodic table. While the model does not account for nuclear binding energy variations, shell effects, or neutron excess, it provides a universal geometric and electromagnetic baseline for nuclear size. It may serve as a first-principles lower-bound estimator in many cases, though occasional overestimation indicate that it is best interpreted as a natural scale floor ratherthan a strict minimum.