Thermodynamics is a beautiful illustration of how needs of very practical applications can lead to very basic, general concepts and relations, very much in contrast to the view that the practical and applied facets of a science are consequences of prior basic studies. Thermodynamics teaches us that ideas and concepts can flow in either direction, between the basic and the applied. It was the very practical challenge of finding the best, most efficient way to pump water out of tin mines in Cornwall and elsewhere that stimulated the thinking, notably the young French engineer Sadi Carnot, that led us to the very basic, general concepts, even laws of nature, that we call “thermodynamics”.
Traditional, classical thermodynamics is deeply based on the concept that processes and machines have limits to how efficiently they can carry out their tasks, limits that minimize the wasteful losses that all real processes have. And traditional thermodynamics focuses on finding those limits and hence on how best to get real systems to approach those limits. (Any system that would operate at its ideal limit would operate infinitely slowly and one could not tell whether it was going forward or backward. Ideal processes of that sort are called “reversible”.) But we can see how a science evolves by asking new questions, in the case of thermodynamics, of asking how real systems behave and how they differ from those ideal but unreachable ideal limits. When people began to ask those questions, the science of thermodynamics took on a whole new character and direction. “Irreversible thermodynamics” is the name that new direction took on. And when thermodynamics began examining the consequences of operating a system in real time, that new aspect became known as “finite-time thermodynamics”.
Thermodynamics is, in some ways, the science that most influences our daily lives, because we use its concepts and information in the ways we design and operate so many of the devices we take for granted in our daily lives. Heating and cooling systems in our homes and other buildings, engines that power our motor vehicles, even the design of buildings and vehicles, all incorporate information from thermodynamics to make them perform well. However, in contrast to many other sciences, the way it influences our daily lives is much more subtle, even invisible. We are much more aware of what biology is doing for us every day, or what new devices are coming from quantum physics than of how thermodynamics is influencing our daily lives (although quantum physics does lead to novel aspects of thermodynamics).
The primary impact thermodynamics has on our daily lives is the many ways it shows us how to use energy efficiently, and minimize the wastes that inevitably accompany that use. One of the earliest examples appeared at the birth of the subject, when the work by the French engineer Sadi Carnot revealed that the highest temperatures in any cycle driving a heat engine should be as high as possible. Thermodynamics tells us just how important it is to minimize friction and heat losses through the walls of our engines, and it can tell us, for example, what is the best temperature profile for a distillation column to achieve the most efficient performance. It tells us how to build houses that require little or no heating fuel. Hence thermodynamics becomes a guide to design devices that best perform as we would
The primary impact thermodynamics has on our daily lives is the many ways it shows us how to use energy efficiently, and minimize the wastes that inevitably accompany that use. One of the earliest examples appeared at the birth of the subject, when the work by the French engineer Sadi Carnot revealed that the highest temperatures in any cycle driving a heat engine should be as high as possible. Thermodynamics tells us just how important it is to minimize friction and heat losses through the walls of our engines, and it can tell us, for example, what is the best temperature profile for a distillation column to achieve the most efficient performance. It tells us how to build houses that require little or no heating fuel. Hence thermodynamics becomes a guide to design devices that best perform as we would
R. Stephen Berry is James Franck Distinguished Service Professor Emeritus at the University of Chicago and a 1983 MacArthur Fellow. His work has contributed to the understanding of the atomic origins of freezing, melting, crystallization, and glass formation.
