Thermodynamics of Life

• Main Author: Marc Henry
• Format: Article
• Language: English
• Published: Firenze University Press 2021-03-01
• Series: Substantia
• Subjects: entropy; life; death; thermodynamics; irreversibility; heat
• Online Access: https://riviste.fupress.net/index.php/subs/article/view/959

Biology is currently plagued by several fossil concepts that may be responsible for the current stagnation in medicine. Through a careful screening of the origins of thermodynamics, such fossils concepts have been identified: assumption that heat is a form of energy, assimilation of entropy to disorder, assimilation of death to states of maximum entropy, assimilation of ATP to the energy currency of living cells, non-recognition of entropy as a state function of the whole universe, belief that free energies are another kind of energy, self-referencing in the definition of life, ignorance of basic principles of quantum physics and more particularly of the importance of intrinsic spin, confusion between three different forms of reversibility, non-recognition that irreversibility is at the heart of living systems. After stowing of these concepts in the cabinet of useless and nasty notions, a fresh new look is proposed showing how life is deep-rooted trough the entropy concept in quantum physics on the one hand and in cosmology on the other hand. This suggests that life is not an emergent property of matter, but rather that it has always been a fundamental property of a universe filled with particles and fields. It is further proposed to dismiss the first (energy = heat + work) and third laws (entropy decreases to zero at zero Kelvin) of thermodynamics, retaining only the clear Boltzmann's definition of entropy in terms of multiplicity of microstates Ω, S = kB×Ln Ω, and the second law in its most general form applicable to any kind of macrostates: ∆Suniv ≥ 0. On this ground, clear definitions are proposed for life/death, healthiness/illness and for thermodynamic coupling. The whole unfolding of life in the universe: Big Bang → Light → Hydrogen → Stars → Atoms → Water → Planets → Metabolism → Lipids → RNA's → Viruses → Ribosome → Proteins → Bacteria → Eukaryote → Sex → Plants → Animals → Humans → Computers → Internet, may then be interpreted as a simple consequence of a single principle: ∆Suniv ≥ 0. We thus strongly urge biologists and physicians to change and adapt their ideas and vocabulary to the proposed reformulation for a better understanding of what is life and as a consequence for better health for living beings.