The Principles of Quantum Mechanics

The Principles of Quantum Mechanics is an influential monograph on quantum mechanics written by Paul Dirac and first published by Oxford University Press in 1930. Dirac gives an account of quantum mechanics by "demonstrating how to construct a completely new theoretical framework from scratch"; "problems were tackled top-down, by working on the great principles, with the details left to look after themselves". It leaves classical physics behind after the first chapter, presenting the subject with a logical structure. Its 82 sections contain 785 equations with no diagrams.

Dirac is credited with developing the subject "particularly in Cambridge and Göttingen between 1925–1927" (Farmelo). It is considered one of the most influential texts on quantum mechanics, with theoretical physicist Laurie M. Brown stating that it "set the stage, the tone, and much of the language of the quantum-mechanical revolution".

History
The first and second editions of the book were published in 1930 and 1935.

In 1947 the third edition of the book was published, in which the chapter on quantum electrodynamics was rewritten particularly with the inclusion of electron-positron creation.

In the fourth edition, 1958, the same chapter was revised, adding new sections on interpretation and applications. Later a revised fourth edition appeared in 1967.

Beginning with the third edition (1947), the mathematical descriptions of quantum states and operators were changed to use the Bra–ket notation, introduced in 1939 and largely developed by Dirac himself.

Laurie Brown wrote an article describing the book's evolution through its different editions, and Helge Kragh surveyed reviews by physicists (including Werner Heisenberg, Wolfgang Pauli, and others) from the time of Dirac's book's publication.

Contents

 * The principle of superposition
 * Dynamical variables and observables
 * Representations
 * The quantum conditions
 * The equations of motion
 * Elementary applications
 * Perturbation theory
 * Collision problems
 * Systems containing several similar particles
 * Theory of radiation
 * Relativistic theory of the electron
 * Quantum electrodynamics