Inevitability of Relativistic Structure in Central-Regime–Admitting Causal Update Systems

Title:Inevitability of Relativistic Structure in Central-Regime–Admitting Causal Update Systems Description: This paper investigates why relativistic spacetime structure is not a contingent choice but an unavoidable consequence in a broad class of systems that admit observers and shared descriptions. Building on the completed framework of Causal Update Cosmology (CUC I–IX) and the operational criteria known as the Four Gates, this work considers causal update systems that admit a central regime—the regime in which stable observerhood, reproducible comparison, and effective law-like descriptions become possible. The central question addressed is not how to derive relativity, nor how to reconstruct its formalism. Instead, the paper asks a more structural question:once finite causal update, observer emergence, and inter-observer shareability are simultaneously required, which spacetime descriptions remain admissible, and which are structurally excluded? Using conceptual and structural reasoning alone—without introducing relativistic postulates, equations, numerical simulations, or master equations—the paper demonstrates that absolute time and observer-independent spacetime descriptions cannot be sustained under these conditions. Furthermore, it shows that any description lacking observer-invariant relations collapses into inconsistency when multiple observers coexist. As a result, all non-relativistic spacetime descriptions are excluded from the class of structurally admissible descriptions. What remains is a relativistic structure in a strictly structural sense: observer-dependent quantities together with invariant relations that allow consistent translation between observers. Importantly, this work does not argue for the empirical correctness of relativity, nor does it propose a new physical theory. Relativity is not assumed, reconstructed, or postulated. Rather, it is shown to emerge as the minimal surviving structure once all incompatible alternatives are eliminated. Gravity, quantum theory, and cosmological dynamics are deliberately excluded from the present scope and will be addressed in subsequent work. In this sense, relativity is not chosen.It is what remains. Note on AI Use This work also explores the broader question of whether new physical theories can emerge through collaboration with AI systems. ChatGPT (OpenAI) was used extensively in the generation and structuring of theoretical ideas and manuscript text, beyond simple editing or polishing. All numerical experiments and scientific validation were performed by the human author.