Don S. Lemons – författare

An account of the concepts and intellectual structure of classical thermodynamics that reveals the subject''s simplicity and coherence.

Students of physics, chemistry, and engineering are taught classical thermodynamics through its methods—a “problems first” approach that neglects the subject''s concepts and intellectual structure. In Thermodynamic Weirdness, Don Lemons fills this gap, offering a nonmathematical account of the ideas of classical thermodynamics in all its non-Newtonian “weirdness.” By emphasizing the ideas and their relationship to one another, Lemons reveals the simplicity and coherence of classical thermodynamics.

Lemons presents concepts in an order that is both chronological and logical, mapping the rise and fall of ideas in such a way that the ideas that were abandoned illuminate the ideas that took their place. Selections from primary sources, including writings by Daniel Fahrenheit, Antoine Lavoisier, James Joule, and others, appear at the end of most chapters. Lemons covers the invention of temperature; heat as a form of motion or as a material fluid; Carnot''s analysis of heat engines; William Thomson (later Lord Kelvin) and his two definitions of absolute temperature; and energy as the mechanical equivalent of heat. He explains early versions of the first and second laws of thermodynamics; entropy and the law of entropy non-decrease; the differing views of Lord Kelvin and Rudolf Clausius on the fate of the universe; the zeroth and third laws of thermodynamics; and Einstein''s assessment of classical thermodynamics as “the only physical theory of universal content which I am convinced will never be overthrown.”

What does the path taken by a ray of light share with the trajectory of a thrown baseball and the curve of a wheat stalk bending in the breeze? Each is the subject of a different study yet all are optimal shapes; light rays minimize travel time while a thrown baseball minimizes action. All natural curves and shapes, and many artificial ones, manifest such "perfect form" because physical principles can be expressed as a statement requiring some important physical quantity to be mathematically maximum, minimum, or stationary. Perfect Form introduces the basic "variational" principles of classical physics (least time, least potential energy, least action, and Hamilton''s principle), develops the mathematical language most suited to their application (the calculus of variations), and presents applications from the physics usually encountered in introductory course sequences. The text gradually unfolds the physics and mathematics. While other treatments postulate Hamilton''s principle and deduce all results from it, Perfect Form begins with the most plausible and restricted variational principles and develops more powerful ones through generalization. One selection of text and problems even constitutes a non-calculus of variations introduction to variational methods, while the mathematics more generally employed extends only to solving simple ordinary differential equations. Perfect Form is designed to supplement existing classical mechanics texts and to present variational principles and methods to students who approach the subject for the first time.