
Quantum mechanics and a preliminary investigation of the hydrogen atom
Author(s) -
P. A. M. Dirac
Publication year - 1926
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1926.0034
Subject(s) - physics , quantum mechanics , commutative property , constant (computer programming) , mathematical physics , quantum , mathematics , theoretical physics , pure mathematics , computer science , programming language
Although the classical electrodynamic theory meets with a considerable amount of success in the description of many atomic phenomena, it fails completely on certain fundamental points. It has long been thought that the way out of this difficulty lies in the fact that there is one basic assumption of the classical theory which is false, and that if this assumption were removed and replaced by something more general, the whole of atomic theory would follow quite naturally. Until quite recently, however, one has had no idea of what this assumption could be. A recent paper by Heisenberg* provides the clue to the solution of this question, and forms the basis of a new quantum theory. According to Heisenberg, ifx andy are two functions of the co-ordinates and momenta of a dynamical system, then in generalxy is not equal toyx . Instead of the commutative law of multiplication, the canonical variablesqr pr (r = 1...u ) of a system ofu degrees of freedom satisfy the quantum conditions, which were given by the author in the formqr qs ―qs qr = 0pr ps ―ps pr = 0qr ps ―ps qr = 0qr pr ―pr qr =ih (r ≠s ) } (1) wherei is a root of — 1 andh is a real universal constant, equal to (2π )-1 times the usual Planck’s constant. These equations are just sufficient to enable one to calculatexy —yx whenx andy are given functions of thep’ s andq’ s, and are therefore capable of replacing the classical commutative law of multiplication. They appear to be the simplest assumptions one could make which would give a workable theory.