In April of 1956, Hugh Everett III’s draft doctoral thesis, tentatively titled “Wave Mechanics without Probability”, was circulated by his thesis advisor at Princeton University John Wheeler to several leading physicists in the West, including the godfather of quantum mechanics Niels Bohr. Everett aimed at resolving the measurement problem in quantum mechanics. Everett’s solution to the mystery of how, when, where and why the wave function collapses in the measurement process was straightforward: it does not. Due to the opposition of Bohr and other adherents to the Copenhagen Interpretation of quantum mechanics, an objection by Feynman and Wheeler’s growing ambivalence, Everett was required to abridge his thesis, resulting in the publication of “’Relative State’ Formulation of Quantum Mechanics” in July 1957. Everett’s machinery of interpretation, including his information and measure theoretic interpretation of the wave function, his concept of correlation within the superposition, as well as his philosophy of science which provides important context for his theory, are largely absent from the latter “Short Thesis”. Perhaps due to the unusual publication history of his works, many critics of Everett and even many of his supporters have overlooked the significance of the arguments made in the “Long Thesis”, which was published only in 1973. Everett’s fuller exposition there answers often cited criticisms such as Adrian Kent’s “Against Many Worlds Interpretations”. Other popular misconceptions about Everett, that he was driven out of academia or that his thesis was redacted due solely or primarily to the opposition from Copenhagen, do not stand up to careful scrutiny of the historical evidence.
In April of 1956, Hugh Everett III’s draft doctoral thesis, tentatively titled “Wave Mechanics without Probability”, was circulated by his thesis advisor at Princeton University John Wheeler to several leading physicists in the West, including the godfather of quantum mechanics Niels Bohr. Everett aimed at resolving the measurement problem in quantum mechanics. Everett’s solution to the mystery of how, when, where and why the wave function collapses in the measurement process was straightforward: it does not. Due to the opposition of Bohr and other adherents to the Copenhagen Interpretation of quantum mechanics, an objection by Feynman and Wheeler’s growing ambivalence, Everett was required to abridge his thesis, resulting in the publication of “’Relative State’ Formulation of Quantum Mechanics” in July 1957. Everett’s machinery of interpretation, including his information and measure theoretic interpretation of the wave function, his concept of correlation within the superposition, as well as his philosophy of science which provides important context for his theory, are largely absent from the latter “Short Thesis”. Perhaps due to the unusual publication history of his works, many critics of Everett and even many of his supporters have overlooked the significance of the arguments made in the “Long Thesis”, which was published only in 1973. Everett’s fuller exposition there answers often cited criticisms such as Adrian Kent’s “Against Many Worlds Interpretations”. Other popular misconceptions about Everett, that he was driven out of academia or that his thesis was redacted due solely or primarily to the opposition from Copenhagen, do not stand up to careful scrutiny of the historical evidence.
Hugh Everett's long thesis was submitted to John Archibald Wheeler, his doctoral thesis advisor, in January 1956 under the title "Quantum Mechanics by the Method of the Universal Wave Function.'' It was retitled "Wave Mechanics Without Probability'' and circulated in April of that year to several prominent physicists, including Niels Bohr. Largely due to the criticism of the long thesis by the Copenhagen colleagues, Everett and his advisor John Wheeler rewrote Everett's thesis in the winter of 1957 to produce a much shorter version, which Everett subsequently defended for his Ph.D. under the title "On the Foundations of Quantum Mechanics.'' While the long thesis was organized around the quantum measurement problem and how it is best solved by pure wave mechanics, the short thesis presented Everett's relative-state formulation of pure wave mechanics more as a suitable theory for the development of quantum gravity, cosmology, and field theory. The short thesis no longer contains Everett's chapter on information theory and correlation, his survey of possible solutions to the measurement problem, or his extended discussion of the nature of physical theories. What remains is a distilled presentation of pure wave mechanics, his principle of the fundamental relativity of states, and his derivation of the standard quantum statistics. The short thesis was retitled for publication in Reviews of Modern Physics in July 1957 as "The 'Relative State' Formulation of Quantum Mechanics.'' The version below closely follows the Reviews of Modern Physics article. The long thesis itself was not published until 1973 in the DeWitt and Graham Princeton University Press anthology. It was published under the title "The Theory of the Universal Wave Function." Although Everett did not publish the long thesis, he nonetheless kept a copy of it, and appears to have returned to it periodically to make changes even after the short thesis appeared in print. This document is a scanned version of Everett's personal copy of his long thesis, with his collected comments and changes.
Hugh Everett's long thesis was submitted to John Archibald Wheeler, his doctoral thesis advisor, in January 1956 under the title "Quantum Mechanics by the Method of the Universal Wave Function.'' It was retitled "Wave Mechanics Without Probability'' and circulated in April of that year to several prominent physicists, including Niels Bohr. Largely due to the criticism of the long thesis by the Copenhagen colleagues, Everett and his advisor John Wheeler rewrote Everett's thesis in the winter of 1957 to produce a much shorter version, which Everett subsequently defended for his Ph.D. under the title "On the Foundations of Quantum Mechanics.'' While the long thesis was organized around the quantum measurement problem and how it is best solved by pure wave mechanics, the short thesis presented Everett's relative-state formulation of pure wave mechanics more as a suitable theory for the development of quantum gravity, cosmology, and field theory. The short thesis no longer contains Everett's chapter on information theory and correlation, his survey of possible solutions to the measurement problem, or his extended discussion of the nature of physical theories. What remains is a distilled presentation of pure wave mechanics, his principle of the fundamental relativity of states, and his derivation of the standard quantum statistics. The short thesis was retitled for publication in Reviews of Modern Physics in July 1957 as "The `Relative State' Formulation of Quantum Mechanics.'' The version below closely follows the Reviews of Modern Physics article. The long thesis itself was not published until 1973 in the DeWitt and Graham Princeton University Press anthology. It was published under the title "The Theory of the Universal Wave Function." This document is a reproduction of the version of the thesis published in the DeWitt-Graham anthology.
Hugh Everett III was an American physicist best known for his many-worlds interpretation of quantum mechanics, which formed the basis of his PhD thesis at Princeton University in 1957. Although counterintuitive, Everett's revolutionary formulation of quantum mechanics offers the most direct solution to the infamous quantum measurement problem--that is, how and why the singular world of our experience emerges from the multiplicities of alternatives available in the quantum world. The many-worlds interpretation postulates the existence of multiple universes. Whenever a measurement-like interaction occurs, the universe branches into relative states, one for each possible outcome of the measurement, and the world in which we find ourselves is but one of these many, but equally real, possibilities. Everett's challenge to the orthodox interpretation of quantum mechanics was met with scorn from Niels Bohr and other leading physicists, and Everett subsequently abandoned academia to conduct military operations research. Today, however, Everett's formulation of quantum mechanics is widely recognized as one of the most controversial but promising physical theories of the last century. In this book, Jeffrey Barrett and Peter Byrne present the long and short versions of Everett's thesis along with a collection of his explanatory writings and correspondence. These primary source documents, many of them newly discovered and most unpublished until now, reveal how Everett's thinking evolved from his days as a graduate student to his untimely death in 1982. This definitive volume also features Barrett and Byrne's introductory essays, notes, and commentary that put Everett's extraordinary theory into historical and scientific perspective and discuss the puzzles that still remain.
Hugh Everett III was an American physicist best known for his many-worlds interpretation of quantum mechanics, which formed the basis of his PhD thesis at Princeton University in 1957. Although counterintuitive, Everett's revolutionary formulation of quantum mechanics offers the most direct solution to the infamous quantum measurement problem--that is, how and why the singular world of our experience emerges from the multiplicities of alternatives available in the quantum world. The many-worlds interpretation postulates the existence of multiple universes. Whenever a measurement-like interaction occurs, the universe branches into relative states, one for each possible outcome of the measurement, and the world in which we find ourselves is but one of these many, but equally real, possibilities. Everett's challenge to the orthodox interpretation of quantum mechanics was met with scorn from Niels Bohr and other leading physicists, and Everett subsequently abandoned academia to conduct military operations research. Today, however, Everett's formulation of quantum mechanics is widely recognized as one of the most controversial but promising physical theories of the last century.
In this book, Jeffrey Barrett and Peter Byrne present the long and short versions of Everett's thesis along with a collection of his explanatory writings and correspondence. These primary source documents, many of them newly discovered and most unpublished until now, reveal how Everett's thinking evolved from his days as a graduate student to his untimely death in 1982. This definitive volume also features Barrett and Byrne's introductory essays, notes, and commentary that put Everett's extraordinary theory into historical and scientific perspective and discuss the puzzles that still remain.
The interpretation of quantum mechanics has been disputed ever since the advent of the theory in the 1920’s. Famous are the discussions over long time between Einstein and Bohr. Einstein refused to accept the so‐called Copenhagen interpretation, where the wave function collapses at a measurement and where the outcome of the measurement is essentially accidental (“God does not play dice”). Alternative interpretations have appeared, but the Copenhagen school has dominated the thoughts throughout the decades. One interesting interpretation was formulated in 1957 by Hugh Everett at Princeton, a student of John Wheeler, which abandons the wave‐function collapse. In this model the universe is governed entirely by the Schrödinger equation, which does not allow for any collapse. In Everett’s model after a measurement the wave function is separated into different branches that do not interact. This model was left unnoticed for long time until Bryce DeWitt took it up in 1970 and termed it “Many‐Worlds Interpretation”, a term that in some sense is misleading. Everett’s model is incomplete, and it was later supplemented by the theory of decoherence, which explains how the different branches decouple as a result of the interaction with the environment. This extended model has in recent years gained increased respect, and some believe that it is the only model made available so far that is fully consistent with quantum mechanics. This interpretation can also shed some light on the development of the universe and, in particular, on the so‐called Anthropic principle, which puts human beings at the center of the development.
A novel interpretation of quantum mechanics, first proposed in brief form by Hugh Everett in 1957, forms the nucleus around which this book has developed. In his interpretation, Dr. Everett denies the existence of a separate classical realm and asserts the propriety of considering a state vector for the whole universe. Because this state vector never collapses, reality as a whole is rigorously deterministic. This reality, which is described jointly by the dynamical variables and the state vector, is not the reality customarily perceived; rather, it is a reality composed of many worlds. By virtue of the temporal development of the dynamical variables, the state vector decomposes naturally into orthogonal vectors, reflecting a continual splitting of the universe into a multitude of mutually unobservable but equally real worlds, in each of which every good measurement has yielded a definite result, and in most of which the familiar statistical quantum laws hold. The volume contains Dr. Everett's short paper from 1957, "'Relative State' Formulation of Quantum Mechanics," and a far longer exposition of his interpretation, entitled "The Theory of the Universal Wave Function," never before published. In addition, other papers by Wheeler, DeWitt, Graham, and Cooper and Van Vechten provide further discussion of the same theme. Together, they constitute virtually the entire world output of scholarly commentary on the Everett interpretation. Originally published in 1973. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.