This title is part of UC Press's Voices Revived program, which commemorates University of California Press’s mission to seek out and cultivate the brightest minds and give them voice, reach, and impact. Drawing on a backlist dating to 1893, Voices Revived makes high-quality, peer-reviewed scholarship accessible once again using print-on-demand technology. This title was originally published in 1992.

The history of quantum theory is a maze of conceptual problems. In this lucid and learned book, Olivier Darrigol tracks the role of formal analogies between classical and quantum theory, from Planck's first introduction of the quantum of action to Dirac's formulation of quantum mechanics. In so doing, Darrigol illuminates not only the history of quantum theory but also the role of analogies in scientific thinking and theory change. The most remarkable result of such analogical argument in quantum theory was Bohr's correspondence principle which, in Darrigol's words, "performed the acrobatic task of bridging two mutually contradictory theories (classical electrodynamics and atomic theory), without diminishing the contrast between them". By analyzing the origins, development, and applications of this principle, From c-Numbers to q-Numbers explains the remarkable fruitfulness of the research done under Bohr's guidance between 1916 and 1925 and shows why Heisenberg claimed that quantum mechanics was born as "a quantitative formulation of the correspondence principle". With a physicist's sure hand, Darrigol examines the formal and the epistemological aspects of the analogy between classical and quantum mechanics. Unlike previous works, which have tended to focus on qualitative, global arguments, he follows the lines of mathematical reasoning and symbolizing, and by doing so he is able to show the motivations of early quantum theorists more precisely - and provocatively - than ever before. For instance, Darrigol demonstrates that a universal principle of elementary chaos underlay Planck's analogies, and that Bohr's correspondence principle was related to his elaboration of a minimal-quantumtheoretical language. Most striking, Darrigol reveals how Dirac's personal conception of the relations among algebra, geometry, use of the analogy between c-numbers and and physics conditioned his highly creative q-numbers. Original, erudite, and witty, From c-Numbers to q-Numbers sets a new standard for the philosophically perceptive and mathematically precise history of quantum mechanics. For years to come it will influence historical and philosophical discussions of twentieth-century physics.

Geared toward upper-level undergraduates and graduate students, this self-contained first course in quantum mechanics covers basic theory and selected applications and includes numerous problems of varying difficulty. 1992 edition.

The description for this book, The How and the Why, will be forthcoming.

Since the 17th century, physical theories have been expressed in the language of mathematical equations. This introduction to quantum theory uses that language to enable the reader to comprehend the notoriously non-intuitive ideas of quantum physics. The mathematical knowledge needed for using this book comes from standard undergraduate mathematics courses and is described in detail in the section Prerequisites. This text is especially aimed at advanced undergraduate and graduate students of mathematics, computer science, engineering and chemistry among other disciplines, provided they have the math background even though lacking preparation in physics. In fact, no previous formal study of physics is assumed.

Innovative account of the origins of quantum mechanics told from a historical perspective, for advanced undergraduates, graduate students and researchers.

Originally published: Amsterdam: North-Holland Pub. Co., 1967.