(1) Relativistic quantum mechanics. Offprint from Proc. Roy. Soc. 136. (2) (with Vladimir Fock [1898-1974] and Boris Podolsky [1896-1966]) On quantum electrodynamics. Offprint from Physikalische Zeitschrift der Sowjetunion 2

1932. Dirac, Paul A. M. (1902-84). (1) Relativistic quantum mechanics. Offprint from Proceedings of the Royal Society, A, 136 (1932). 453-464pp. 254 x 177 mm. Original printed wrappers, a bit dust-soiled, vertical creasing. Very good. (2) (with Vladimir Fock [1898-1974] and Boris Podolsky [1896-1966]) On quantum electrodynamics. Offprint from Physikalische Zeitschrift der Sowjetunion 2 (1932). 468-479pp. 224 x 152 mm. Original printed self-wrappers, creased vertically, slight soiling. Very good. Together 2 offprints. First Editions, Offprint Issues of Dirac’s papers introducing his own approach to quantum electrodynamics, which inspired Schwinger and (truncated) Tomonaga’s Nobel Prize-winning work on the development of modern QED in the 1940s. Dirac founded quantum electrodynamics in 1927 with his landmark paper, “The quantum theory of the emission and absorption of radiation,” but after this paper he did not return to the subject of QED until 1932, when he published “Relativistic quantum mechanics” (no. [1] above). In this paper Dirac explicitly rejected Heisenberg and Pauli’s approach to QED set forth in their two-part joint paper of 1929-30, replacing it with his own formulation, which he believed provided a better foundation for quantum field theory. Dirac’s alternative approach to QED was soon shown to be mathematically equivalent to the Heisenberg-Pauli theory; however, Dirac felt that his version was superior from a conceptual point of view and continued to develop it in “On quantum electrodynamics” (no. [2] above), co-authored with Russian physicists Vladimir Fock and Boris Podolsky. The formal innovations outlined in Dirac’s two papers “proved to be important for the later development of quantum electrodynamics. When the emergence of modern renormalization techniques finally provided a breakthrough for the theory in 1947-8, Dirac’s papers served as an important source of inspiration. Julian Schwinger, one of the architects of the new theory, was inspired by the Dirac-Podolsky-Fock formulation; he developed it greatly and also coined the term ‘interaction representation.’ Sin-Itoro Tomonaga, another of the fathers of modern quantum electrodynamics, was fascinated by Dirac’s 1932 paper, which ‘attracted my interest because of the novelty of its philosophy and the beauty of its form. The long and troublesome road toward renormalization thus took its start in aspects of Dirac’s work” (Kragh, p. 138). Kragh, Dirac: A Scientific Biography. . (Inventory #: 50820)