Book reviewed: The Demon in the Machine: How Hidden Webs of Information Are Solving the Mystery of Life by Paul C.W. Davies

Does the information processing explain the order of a living cell This book discusses how entropy, once viewed purely in terms of thermodynamics and physical systems, evolved to explain the structural complexity and orderly functions of a living cell. This book also makes it relevant that in biology coupling between processes on many scales of size and complexity occurs, and the biological causation operates both ways in a living system, bottom-up from genes to organisms, and top-down, from organisms to genes. The author discusses how the Maxwell’s “Demon” of the second law of thermodynamics appears to defy a thermodynamic process by reducing entropy internally in a physical system also applies to biological cells that maintain order by reducing entropy internally. The title of the book refers to James Maxwell’s "Demon," a thought experiment about the second law of thermodynamics. It is a hypothetical entity that violates this law by sorting particles between two compartments separated by a transparent wall of a simple physical system. Consideration of information gathered by the demon during the categorization of the particles requires energy and thus the total entropy of the system actually increases. The interplay between thermodynamics and information theory is challenging and helpful in advancing scientific thought. This book discusses how the concept of cellular entropy connects with the storage and processing of information in biological processes. The book is very engaging, and author Paul Davies describes physics, biology, and evolution with ease. But it is unlikely to be a complete explanation. The complexity of life requires a multifaceted approach that considers factors such as self-organization, evolution, the role of energy and information processing in biological processes. This book does not explain how life (a living cell) emerged from non-life (matter).