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Entropy Bathtub for Living Systems: A Markovian Perspective
1Physics of Complex Systems Division, Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-632 Warszawa, Poland.
Entropy (Basel, Switzerland)
|February 27, 2026
Summary
Living organisms are dissipative systems. Their entropy follows an "entropy bathtub" trajectory: decreasing during growth, stabilizing at maturity, and increasing during aging, reflecting universal thermodynamic principles.
Area of Science:
- Thermodynamics
- Biophysics
- Physical Chemistry
Background:
- Living organisms function as dissipative, self-organizing physical systems operating far from thermodynamic equilibrium.
- Markov jump processes and stochastic thermodynamics offer frameworks for describing these non-equilibrium systems.
Purpose of the Study:
- To demonstrate the temporal evolution of entropy in living systems using a thermodynamic model.
- To introduce the concept of the "entropy bathtub" trajectory for living systems.
- To explore the impact of external stressors on these systems.
Main Methods:
- Combined Markov formalism with stochastic thermodynamics.
- Modeled living systems as dissipative systems under external driving forces.
- Analyzed entropy production and temporal evolution.
Main Results:
- Demonstrated a characteristic entropy trajectory termed the "entropy bathtub": decrease during growth, stabilization at maturity (non-equilibrium steady state - NESS), and increase during aging/death.
- Showed continuous, time-dependent positive entropy production.
- Modeled external perturbations as analogous to pathological processes.
Conclusions:
- The "entropy bathtub" trajectory highlights the universal thermodynamic structure of life.
- The model provides a tool for exploring entropy-driven mechanisms in living matter.
- External stressors can be conceptually modeled through perturbations of the driving force.
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