Dimensional Electrodynamics Working Note: Toward a Plausible Unobserved PhotonicLaw Coupling 4D Electromagnetism to Higher-Dimensional Structure This document is written as an open letter to CERN physicists and associated experimentaland theoretical groups. Its purpose is to request focused attention on what appears to bea physically admissible, symmetry-compatible, and experimentally testable extension ofMaxwell electrodynamics. In brief: if photons in 3+ 1 dimensions (X) are allowed to coupleto, or partially propagate through, compact extra directions in a higher-dimensional ambientmanifold (Y ), then standard Maxwell theory on X should be deformed in a specific, derivableway. That deformation implies a conserved cross-dimensional charge and predicts a nonzerofloor in interferometric visibility. The claim here is that such a law is plausible, not exotic,and that it has not yet been explicitly instrumented for.What follows is a technical statement of that mechanism, together with a direct requestthat CERN evaluate its theoretical consistency and experimental accessibility.The discussion is organized in five points.