Galactic Time and Civilizational Detectability: A Phase-Structured Phenomenon

This preprint introduces a Galactic Time framework for civilisational detectability, proposing that the observability of technological civilisations is fundamentally constrained by time-dependent stability windows rather than by spatial scarcity alone.The framework reframes the Fermi Paradox by treating detectability as a phase-structured phenomenon, where phases refer to detectability states rather than to any fixed, universal, or predictive dynamical cycle. In contrast to traditional Drake-style formulations, Galactic Time incorporates explicit temporal constraints on technological persistence and observability without assuming long-lived or continuously detectable civilisations.Worked examples demonstrate how differing stellar architectures—including single-star, binary, and perturbed systems—naturally produce heterogeneous detectability windows without invoking assumptions of rarity, synchronisation, or universal collapse. These examples are illustrative and system-agnostic, and do not imply calibration to any specific planetary history.The framework defines a distinct category of models for civilisational detectability, reframing observational silence as a consequence of time-dependent system stability rather than spatial absence or inevitable self-destruction. The framework is not predictive without system-specific inputs and does not imply advance knowledge of instability timing.This work is presented as a foundational conceptual contribution, suitable for integration with future observational strategies, computational modelling, and AI-assisted analysis, and is intended to support new approaches to interpreting technosignature searches and long-term system dynamics.