Planck Energy as Collapse Limit: A Structural Interpretation of EP in Quantum Substrate Dynamics

In standard physics, Planck energy (Eₚ) is often treated as a theoretical boundary marking the breakdown of classical descriptions, yet its structural origin remains obscure. In this work, we derive Eₚ from first principles within the framework of Quantum Substrate Dynamics (QSD), a Lorentz-invariant field theory in which all physical action emerges from quantized coherence cycles within a conserved substrate. We show that Eₚ reflects the maximum coherent energy density supportable by a single coherence envelope, defined by the substrate’s transverse propagation limit (cₜ), curvature compliance (G), and the geometric envelope scale (Lcoh). The result yields: Eₚ = (cₜ⁴ / G) · LcohThis expression reframes Planck energy as a structural yield threshold of the substrate—governing when collapse, rupture, or scalar offload becomes compulsory. We contextualize this result within the broader QSD framework, linking it to spectral serialization, causal pacing, and inertial drag. The collapse limit provides a physically grounded mechanism for high-energy emissions, mass-phase instability, and black hole merger frustration, and offers a falsifiable interpretation of the energetic limits observed in nature.