Reviews of Modern Physics, Vol. 29, Number 3: "Relative State" Formulation of Quantum Mechanics

American Physical Society, 1957 4to (26.5 cm), pp. 255-546. Printed wrappers, in a custom-made cloth box (wrappers slightly soiled and creased, corners missing). Hugh Everett III (1930-1982) was an American physicist and mathematician best known for his work on the "Relative State" formulation of quantum mechanics, with the first edition published here on pp. 454-462. Everett introduced the concept of the "many-worlds" interpretation of quantum mechanics. According to the "many-worlds" interpretation, every possible outcome of a quantum measurement is realized in a different universe. This means that every time a quantum measurement is made, the universe splits into multiple parallel universes, each corresponding to a different possible outcome. This interpretation contrasts with the more traditional "Copenhagen" interpretation of quantum mechanics, which holds that a quantum system exists in a state of superposition until it is observed, at which point its wave function collapses into a definite state. Also included in this issue is "Relativistic Invariance and Quantum Phenomena" by Eugene P. Wigner; "Quantum Theory of Fields and Elementary Particles" by W. Heisenberg; "Einstein's and Other Theories of Gravitation" by Suraj N. Gupta, along with papers from the conference on the role of gravitation in physics (January 18-23, 1957).