Introduction to Entropy

The concept of entropy arises in diverse branches of science, including physics, where it plays a crucial role. However, the nature of entropy as a unifying concept is not widely discussed—it is dealt with in a piecemeal manner within different contexts. The interpretation of the concept is also subtly different in each case. This book will draw these diverse threads together and present entropy as one of the crucial physical concepts. It will cover a range of different applications of entropy, from the classical theory of thermodynamics, the statistical approach, entropy in quantum theory, informa- tion theory and finally, its manifestation in black hole physics. Each will be presented in a manner suitable for undergraduates and interested laypersons with no previous knowledge. The book will take an overview of these areas and see to what extent the concept of entropy is being treated in the same way in each, and how it differs.Key Features:• Provides an accessible introduction to the exciting topic of entropy, setting out its manifestations in classical thermodynamics, statistical mechanics, and information theory.• Covers applications in black holes, quantum theory, and Big Bang cosmology.Jonathan Allday taught physics at a range of schools in the UK. After attending the Liverpool Blue Coat School, he took his first degree in Natural Sciences at Cambridge, then gained a PhD in particle physics in 1989 at Liverpool University. Shortly after this, he started work on Quarks Leptons and the Big Bang, now published by Taylor & Francis and available in its third edition, which was intended as a rigorous but accessible introduction to these topics. Since then, he has also written Apollo in Perspective, Quantum Reality (now in its second edition), and Space-time, co-authored a successful textbook and contributed to an encyclopaedia for young scientists. He has also written on aspects of the history and philosophy of science. Outside of physics, Jonathan has a keen interest in cricket and Formula 1.Simon Hands was also educated at the Blue Coat School and Cambridge University, followed by a PhD in theoretical particle physics at the University of Edinburgh. After research positions at the universities of Oxford, Illinois, Glasgow, and then CERN, he taught and researched theoretical and computational physics at Swansea University for almost 30 years. He moved to the University of Liverpool in 2021, where he helps manage the DiRAC high-performance computing facility for astronomy, nuclear and particle physics theory. An elected Fellow of the Learned Society of Wales, Simon enjoys singing and cycling.

Jonathan Allday taught physics at a range of schools in the UK. After attending the Liverpool Blue Coat School, he took his first degree in Natural Sciences at Cambridge, then gained a PhD in par- ticle physics in 1989 at Liverpool University. Shortly after this, he started work on Quarks Leptons and the Big Bang, now published by Taylor & Francis and available in its third edition, which was intended as a rigorous but accessible introduction to these topics. Since then, he has also written Apollo in Perspective, Quantum Reality (now in its second edition), and Space-time, co-authored a successful textbook and contributed to an encyclopaedia for young scientists. He has also written on aspects of the history and philosophy of science. Outside of physics, Jonathan has a keen interest in cricket and Formula 1.Simon Hands was also educated at the Blue Coat School and Cambridge University, followed by a PhD in theoretical particle physics at the University of Edinburgh. After research positions at the universities of Oxford, Illinois, Glasgow, and then CERN, he taught and researched theoretical and computational physics at Swansea University for almost 30 years. He moved to the University of Liverpool in 2021, where he helps manage the DiRAC high-performance computing facility for astronomy, nuclear and particle physics theory. An elected Fellow of the Learned Society of Wales, Simon enjoys singing and cycling.