The Stellar Death Clock: Thermodynamic Constraints on Civilizational Survival

This work proposes a thermodynamically constrained framework for interpreting the Fermi Paradox. Rather than attributing the absence of detectable extraterrestrial civilizations solely to sociological or self-destructive Great Filters, the study explores the possibility that stellar evolution itself may impose a temporal constraint on civilizational longevity for hosts whose main-sequence lifetime is comparable to or shorter than the Sun's. Using the Earth-Sun system as a baseline, the paper develops a mathematical model of the Civilizational Survival Factor ($\Psi$) to relate remaining habitability, energy availability, and complexity-driven maintenance costs. Beyond socio-economic scaling analogies, the framework adds a scaling argument: under four explicitly stated architectural assumptions, the cost of keeping a three-dimensional distributed technosphere coherent grows as $E_{\mathrm{gross}}^{4/3}$, because the light-crossing time grows with the size of the system. Unavoidable logically irreversible operations (Landauer's principle) set a physical floor on this cost. Under this regime, increasing coordination, state synchronization and repair reduce the net free power available for long-term expansion. Classical interstellar exodus scenarios are evaluated against these bounds, suggesting that such strategies are comparatively costly, whereas controlled planetary orbital migration is presented as a comparatively less costly mitigation pathway, without implying that interstellar travel is impossible. This paper does not claim to resolve the Fermi Paradox definitively, but offers a falsifiable theoretical baseline to guide future empirical observations and technosignature modeling.