The Constancy of the Speed of Light as a Structural Limit of Projection in the Quantum Diffusion (QD) Framework

The constancy of the speed of light () in all inertial frames of reference is the foundational postulate of Special Relativity, although its ontological origin remains abstract in classical physics. In this work, we address Lorentz invariance from the framework of Quantum Diffusion (QD) . We propose that the speed limit is not an intrinsic property of objects in extended space , but rather a constraint imposed by the "observation map" that projects multidimensional reality onto accessible 3+1D space. We interpret it as the maximum rate of information propagation allowed by the structure of the ambient coarse-graining . Under this interpretation, Lorentz invariance emerges as a robust symmetry ("pointer state") selected by the environment, guaranteeing that all observers, being constructions of the same reduced state, perceive the same causal update limit.