Internal Structural Time τ as a Universal Structural Aging Measure: Cross-Domain Evidence from Biology, Economics, and Ecology

Description Internal Structural Time τ as a Universal Structural Aging Measure: Cross-Domain Evidence from Biology, Economics, and Ecology This work represents the third stage of a broader research program investigating Internal Structural Time (τ), a concept derived from Union Dipole Theory (UDT) and proposed as a universal measure of structural aging, degradation, and persistence. The research sequence developed as follows: Paper 1 established the distinction between cumulative collapse and coercive collapse, introducing a structural framework for understanding how systems lose continuity over time. Paper 2 demonstrated that Internal Structural Time τ consistently outperforms conventional clock-time derivatives for early warning and degradation detection across 510 engineering systems, including turbofan engines and lithium-ion batteries. The present paper extends the investigation beyond engineering and asks a more fundamental question: Can Internal Structural Time measure structural aging across entirely different domains of reality? To answer this question, the identical τ formulation, alert protocol, and statistical validation procedures are applied to three non-engineering domains: • Biological aging (Gompertz–Makeham mortality dynamics) • Corporate financial decline (Merton structural firm dynamics) • Ecological degradation (coral reef bleaching and tipping-point models) These domains differ completely in physics, mechanisms, timescales, and scientific context. Their only common feature is the existence of structural continuity, burden, repair, and progressive degradation. The results show that τ consistently outperforms the strongest domain-specific competitors across biology, economics, and ecology, extending previous engineering evidence and increasing the total validation base to more than 700 systems spanning multiple physical substrates. The paper argues that Internal Structural Time is not domain-specific but system-specific. Any system capable of persistence, burden accumulation, repair, and structural transformation generates its own internal temporal evolution. This work therefore shifts the interpretation of τ from an engineering prognostic indicator toward a candidate universal measure of structural aging. The paper also serves as the bridge to the next stage of the research program, where the intrinsic properties of Internal Structural Time are investigated, including coordinate invariance and degradation-speed encoding, providing evidence that τ may behave as a genuine structural quantity rather than a derived prediction metric. All datasets, methodology, assumptions, limitations, and statistical procedures are fully documented. Complete reproducibility is provided through embedded Python code and fixed-seed simulations.