The Universal Coherence Principle: A Geometric-Deterministic Foundation for Unifying Quantum and Relativistic Causal Structures

This paper introduces the **Universal Coherence Principle (UCP)**, a deterministic physical law that operates across all scales, from the electron's structure to the cosmological limit of light speed . We argue that the apparent randomness of Quantum Mechanics (QM) is an **epistemic limitation**, an averaging over a complete set of underlying, unobserved geometric variables (). The electron is re-modeled as a self-confined, resonant Field Packet, inheriting its stability directly from the photon’s immutable field geometry, thereby rendering abstract quantum numbers as secondary descriptors of a primary geometric reality. The UCP resolves the conflict between the probabilistic nature of QM and the deterministic causality of General Relativity (GR) by proving that the universal speed limit is the geometrically derived constant of ultimate field stability.