Reviewed by Ian Lipke
Physics for many students has the same effect as being caught by police for running a traffic light – you want to just run away and hide. If that is you, then there is no more need to panic. To qualify that statement a little: if you’re studying thermodynamics with Professor Berry of Yale University, you’re Ok. The rest may want to hide.
Berry’s little book comes with a specific purpose that is emblazoned across the Preface. The book has been written for non-specialists in science, for people who want to know what science is and how it came to be. Berry had to decide whether his audience would respond better if he produced the history first and the science second or teach the two in reverse order. He chose the reverse. Having read the book, I think his choice was a wise one. Chapters One and Two explain what thermodynamics is. Here I found concepts explained in very simple language, much easier to read than that of any newspaper. Concepts, such as the second law of thermodynamics, require some level of mathematics understanding, but no more than anyone with basic mathematics can understand.
These were the chapters that I thought would lose me. That turned out not to be the case. I realised then just why the language was as it was. The writing was simplicity itself, suggesting that it had taken a major effort on Berry’s part to bring about this simplicity effect. The two chapters dealt with the three laws of thermodynamics: the conservation of energy, the inevitability and direction of change with time, and the existence of a limiting absolute zero of temperature.
Chapter Three takes a serious look at the tortuous path that our knowledge of thermodynamics has followed. “it offers a rich insight into how a science evolves, often having to resolve competing, conflicting concepts” (ix). Chapter Four is about Applications, Chapter Five describes how this branch of science continues to evolve. Chapter Six considers the future, while the final chapter considers how a specific science, thermodynamics, can shine a light on the other sciences so that the uninformed know how scientific knowledge differs from other forms of knowledge.
A more detailed examination of Chapter Three than has been possible before now adds a slough of scientific knowledge that non-scientists would grasp only if they were prepared to wade through heavy concepts presented one after the other. Readers had been warned that the way was winding and treacherous. Such it proved to be and by the time I reached the end of the chapter I really could not care less for the history of thermodynamics. I wanted to return to the clinical judgments of Chapters One and Two. The highlight for me in Chapter Three was simply this:
The problem of reconciling the second law [of thermodynamics] with Newtonian mechanics did receive a satisfactory resolution through the recognition of the importance of statistics, and the creation of what we now call statistical mechanics…the validity of the second law does rest in the nature of statistics and statistically governed behaviour (91).
In Chapter Four the interest switches to practical applications of thermodynamics in our world. Beginning with the practical matter of making steam engines more efficient (remember that ‘efficient’ has a very specific meaning in applied mathematics, a point that Berry makes clear on page 71), thermodynamics had led us to appropriately designing and working with refrigeration, air conditioning, the generation of electricity – the latter being particularly interesting. Most of us would not greatly care that, when we run a refrigerator, an amount of heat is generated in converting from one form of energy into another. Boffins (not meant in any derogatory sense) do think of these things and are busy working out ways of turning the generated heat into something useful. The chapter continues on to examine the generation of light from electrical energy leading to why hot systems emit light. The discussion introduces Max Plank and his little packages of light idea.
Berry’s point arising from the interesting (no! give him his due… the fascinating) material in Chapter Four is that “developments demonstrate how our understanding of nature and the world around us is always incomplete and evolving, as we recognize limitations in the explanations we have and use, as we find new ways to explore natural phenomena” (108).
Chapter Five is of the same order of interest as Chapter Four was. Little did I know that the indicator diagram (a graph showing pressure as a function of volume for a typical steam engine) that I skipped in Chapter Three would come back at me in Chapter Five. Using high school mathematics, we enter now the wonderful world of identifying potential ways of improving the performance of an engine, something I’ve sweated nights thinking about (just kidding!) Fascinating but heady mathematics leads the reader into linking thermodynamics to the microscopic structure of matter. Quantum mechanics now becomes integral [pun] to the chapter. An elementary knowledge of the integral calculus, and of bosons and fermions, is useful but not essential to understand this chapter. A theoretical postulation of what might happen if particles trapped in a confining region of space where “all in the lowest possible energy states allowed by the confines of the box” were to approach absolute zero degrees in contravention of the third law of thermodynamics, left me wondering.
That is something that Professor Berry brings to his writing. He presents ideas using the simplest language only to floor his readers with the abstract nature of his ideas. He tantalises, and leaves his reading public gasping for air. This is well illustrated at the beginning of Chapter Six where he introduces the Gibbs phase rule, reminds everybody about some statistics involving degrees of freedom and then, having made more than me a little nervous, simply shows that at a pressure of one atmosphere, there is only one temperature, viz 0 degrees, when water and ice, two phases of a single substance, can be in equilibrium. Berry then gets into optimal control theory, at which time I left him to it.
In Chapter Seven Berry expounds his belief that scientific advances can happen in two directions. The basic science, exemplified by the determination of the helical, sequential structure of DNA eventually led to ways of carrying out genetic control, is science proceeding in one direction. Thermodynamics provides an example of the solution to a practical problem, that of building a pump to assist the mining industry which in turn provided an understanding of heat and the interconvertibility of light, mechanical work, and then electricity. From these understandings came the explicit idea of energy, and the unifying concepts of energy and entropy, which together provided the foundations of an important aspect of science. This is his second direction.
While the book is a combination of very important aspects of physics and statistics with some rough patches along the way, it was a pleasure to read how the English language becomes a powerful weapon in the hands of one who can write simply while explaining very abstract ideas. Well done, Professor Berry. I loved your book.
Three Laws of Nature: a little book on thermodynamics
By R. Stephen Berry
Yale University Press
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