The Dissipation Clock: A Thermodynamic Estimator of Biological Age Based on Non-Equilibrium Energy Flux

Epigenetic clocks predict chronological age with high accuracy by reading accumulated DNA methylation marks. By construction, such clocks are records of elapsed time: they integrate the history of the aging process rather than measuring its instantaneous rate. Even second-generation estimators of the pace of aging, such as DunedinPACE, infer rate from a slowly changing molecular substrate. We propose a complementary class of biological clock grounded in non-equilibrium thermodynamics — specifically Prigogine’s theory of dissipative structures — in which biological age is estimated from the current rate of entropy production and from markers reflecting the quality, pathway, complexity, and structural integrity of the organism’s dissipative apparatus. We define a composite Dissipation Score from five mechanistically grounded readouts: mass-specific resting metabolic rate, the NAD⁺/NADH redox ratio, the resting lactate/pyruvate ratio, heart rate variability, and mitochondrial DNA deletion burden. Using a literature-calibrated synthetic cohort (n = 528, ages 20–85), we show the composite score recovers chronological age with high internal consistency (r = 0.977), establishing the formal coherence of the construction. Because its inputs are fast physiological variables rather than accumulated marks, a dissipation clock should, in principle, respond to interventions that alter the dissipation rate — caloric restriction, mitochondrial uncoupling — in real time rather than with an epigenetic lag. We specify the measurement program required for empirical validation.