The Everett Interpretation of Quantum Mechanics: Collected Works 1955-1980 with Commentary
(Hugh Everett III was an American physicist best known for...)
Hugh Everett III was an American physicist best known for his many-worlds interpretation of quantum mechanics, which formed the basis of his Ph.D. 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 These primary source documents, many of them newly discovered and most unpublished until now, reveal how Everett's thinking evolved from his days as a graduate student to his untimely death in 1982.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 and mathematician. He was the first to propose the many-worlds interpretation (MWI) of quantum physics, which he termed his "relative state" formulation.
Background
Hugh Everett III was born on November 11, 1930, in Washington, District of Columbia, United States. Everett lived in Washington until he was 8 years old, when his family moved to the Washington suburb of Bethesda, Maryland, then still a relatively small city. Except for three years as a graduate student at Princeton University, he spent all of his life in and around Washington, DC. (Washington and its Virginia and Maryland suburbs have by now merged into a single urban complex, its parts linked by the Metro system.)
Everett's grandfather, Hugh Everett Sr., was a printer for the Washington Post at one time. He also owned the Terminal Press, a company where one of his sons, Charles (an uncle of Hugh Everett, III) worked until the mid-1930s. (No later records of the Terminal Press have come to light. Perhaps it, like so many other companies, did not survive the Great Depression.) Hugh Everett Sr. also had two daughters, Kathryn and Virginia.
Everett's father, Hugh Everett Jr. was a native of Washington DC and a graduate of the old Central High School. From 1928 to 1936, he (Hugh, Jr.) held a world rifle record at 1,000 yards. Katherine Kennedy, a graduate of George Washington University and a beginning writer soon became Mrs. Katharine Kennedy Everett and the mother of Hugh Everett III.
In 1936, when Everett was six and America was beginning to recover from the Great Depression, his father, opting for a military career, joined the DC National Guard. Within a couple of years thereafter, Hugh's parents were divorced. Everett subsequently did not have a good relationship with his mother. She spent some time in a mental hospital, possibly on more than one occasion. She published many stories and poems in literary magazines and other publications (interestingly, metaphysics and space were among her subjects). Decades later a posthumous collection of her poetry was published in her university magazine, authorized by her son Hugh Everett III.
In 1940, with war threatening, Everett's father received his commission in the Regular Army. During World War II, he served as a staff officer with General Mark Clark's 5th Army in Italy.
When he was twelve, Everett wrote letters to Albert Einstein raising the question of whether it was something random or unifying that held the universe together. Einstein was kind enough to answer. In a letter dated June 11, 1943, he wrote, "Dear Hugh: There is no such thing like an irresistible force and immovable body. But there seems to be a very stubborn boy who has forced his way victoriously through strange difficulties created by himself for this purpose. Sincerely yours, A. Einstein."
Education
Hugh Everett studied at Saint John's College High School. He enrolled in the Catholic University of America in Washington, choosing chemical engineering as a major. Everett's father was stationed in West Germany, and Hugh joined him, during 1949, taking a year out from his undergraduate studies. He was caught up in the Cold-War mentality of the time, as indicated, for instance, by the fact that after he visited a Spring Fair in Leipzig, East Germany, at age 19, he gave a detailed account of what he saw to an American military officer - a common practice at the time. In 1953 Everett received his bachelor's degree magna cum laude. Everett then attended Princeton University and earned his Doctor of Philosophy in Physics in 1956.
Princeton awarded Everett his doctorate nearly a year after he had begun his first project for the Pentagon: calculating potential mortality rates from radioactive fallout in a nuclear war. He soon headed the mathematics division in the Pentagon’s nearly invisible but extremely influential Weapons Systems Evaluation Group (WSEG). Everett advised high-level officials in the Eisenhower and Kennedy administrations on the best methods for selecting hydrogen bomb targets and structuring the nuclear triad of bombers, submarines, and missiles for an optimal punch in a nuclear strike.
In 1960 Everett helped write WSEG No. 50, a catalytic report that remains classified to this day. According to Everett’s friend and WSEG colleague George E. Pugh, as well as historians, WSEG No. 50 rationalized and promoted military strategies that were operative for decades, including the concept of Mutually Assured Destruction. WSEG provided nuclear warfare policymakers with enough scary information about the global effects of radioactive fallout that many became convinced of the merit of waging a perpetual standoff - as opposed to, as some powerful people were advocating, launching preemptive first strikes on the Soviet Union, China and other communist countries.
One final chapter in the struggle over Everett’s theory also played out in this period. In the spring of 1959, Bohr granted Everett an interview in Copenhagen. They met several times during a six-week period but to little effect: Bohr did not shift his position, and Everett did not reenter quantum physics research. The excursion was not a complete failure, though. One afternoon, while drinking beer at the Hotel Østerport, Everett wrote out on hotel stationery an important refinement of the other mathematical tour de force for which he is renowned, the generalized Lagrange multiplier method, also known as the Everett algorithm. The method simplifies searches for optimum solutions to complex logistical problems - ranging from the deployment of nuclear weapons to just-in-time industrial production schedules to the routing of buses for maximizing the desegregation of school districts.
In 1964 Everett, Pugh, and several other WSEG colleagues founded a private defense company, Lambda Corporation. Among other activities, it designed mathematical models of anti-ballistic missile systems and computerized nuclear war games that, according to Pugh, were used by the military for years. Everett became enamored of inventing applications for Bayes’ theorem, a mathematical method of correlating the probabilities of future events with past experience. In 1971 Everett built a prototype Bayesian machine, a computer program that learns from experience and simplifies decision-making by deducing probable outcomes, much like the human faculty of common sense. Under contract to the Pentagon, Lambda used the Bayesian method to invent techniques for tracking trajectories of incoming ballistic missiles.
In 1973 Everett left Lambda and started a data-processing company, DBS, with Lambda colleague Donald Reisler. DBS researched weapons applications but specialized in analyzing the socioeconomic effects of government affirmative action programs.
Hugh Everett III introduced a new conception of reality to physics and influenced the course of world history at a time when nuclear Armageddon loomed large. To science-fiction aficionados, he remains a folk hero: the man who invented a quantum theory of multiple universes.
(Hugh Everett III was an American physicist best known for...)
2012
Religion
Everett was a "lifelong atheist," according to The Many Worlds of Hugh Everett III (2010) by Peter Byrne. During his time at the Catholic university, Everett "drove devout Jesuits to distraction with scientific questioning" and even caused one of his professors to lose his faith after presenting a logical proof against the existence of God (quoted in The Many Worlds of Hugh Everett III).
Politics
Everett's political philosophy was very similar to what Harry Browne has stated: "One shouldn't waste one's time trying to change the government, since no matter how restrictive government becomes, there will always be ways for a clever person to find loopholes. In fact, the more restrictive it becomes, the more loopholes there will be."
Views
Everett’s scientific journey began one night in 1954, he recounted two decades later, "after a slosh or two of sherry." He and his Princeton classmate Charles Misner and a visitor named Aage Petersen (then an assistant to Niels Bohr) were thinking up "ridiculous things about the implications of quantum mechanics." During this session, Everett had the basic idea behind the many-worlds theory, and in the weeks that followed, he began developing it into a dissertation.
The core of the idea was to interpret what the equations of quantum mechanics represent in the real world by having the mathematics of the theory itself show the way instead of by appending interpretational hypotheses to the math. In this way, the young man challenged the physics establishment of the day to reconsider its foundational notion of what constitutes physical reality.
In pursuing this endeavor, Everett boldly tackled the notorious measurement problem in quantum mechanics, which had bedeviled physicists since the 1920s. In a nutshell, the problem arises from a contradiction between how elementary particles (such as electrons and photons) interact at the microscopic, quantum level of reality and what happens when the particles are measured from the macroscopic, classical level. In the quantum world, an elementary particle, or a collection of such particles, can exist in a superposition of two or more possible states of being. An electron, for example, can be in a superposition of different locations, velocities, and orientations of its spin. Yet anytime scientists measure one of these properties with precision, they see a definite result - just one of the elements of the superposition, not a combination of them. Nor do we ever see macroscopic objects in superpositions. The measurement problem boils down to this question: How and why does the unique world of our experience emerge from the multiplicities of alternatives available in the superposed quantum world?
In stark contrast to the Copenhagen interpretation, Everett addressed the measurement problem by merging the microscopic and macroscopic worlds. He made the observer an integral part of the system observed, introducing a universal wave function that links observers and objects as parts of a single quantum system. He described the macroscopic world quantum mechanically and thought of large objects as existing in quantum superpositions as well. Breaking with Bohr and Heisenberg, he dispensed with the need for the discontinuity of wave-function collapse.
Everett’s radical new idea was to ask. What if the continuous evolution of a wave function is not interrupted by acts of measurement? What if the Schrödinger equation always applies and applies to everything - objects and observers alike? What if no elements of superpositions are ever banished from reality? What would such a world appear like to us?
Everett saw that under those assumptions, the wave function of an observer would, in effect, bifurcate at each interaction of the observer with a superposed object. The universal wave function would contain branches for every alternative making up the object’s superposition. Each branch has its own copy of the observer, a copy that perceived one of those alternatives as the outcome. According to a fundamental mathematical property of the Schrödinger equation, once formed, the branches do not influence one another. Thus, each branch embarks on a different future, independently of the others.
Everett was not the first physicist to criticize the Copenhagen collapse postulate as inadequate. But he broke new ground by deriving a mathematically consistent theory of a universal wave function from the equations of quantum mechanics itself. The existence of multiple universes emerged as a consequence of his theory, not a predicate. In a footnote in his thesis, Everett wrote: "From the viewpoint of the theory, all elements of a superposition (all ‘branches’) are ‘actual,’ none any more ‘real’ than the rest."
The draft containing all these ideas provoked a remarkable behind-the-scenes struggle. In the spring of 1956 Everett’s academic adviser at Princeton, John Archibald Wheeler, took the draft dissertation to Copenhagen to convince the Royal Danish Academy of Sciences and Letters to publish it. He wrote to Everett that he had "three long and strong discussions about it" with Bohr and Petersen. Wheeler also shared his student’s work with several other physicists at Bohr’s Institute for Theoretical Physics, including Alexander W. Stern.
Wheeler’s letter to Everett reported: "Your beautiful wave function formalism, of course, remains unshaken; but all of us feel that the real issue is the words that are to be attached to the quantities of the formalism." For one thing, Wheeler was troubled by Everett’s use of "splitting" humans and cannonballs as scientific metaphors. His letter revealed the Copenhagenists’ discomfort over the meaning of Everett’s work. Stern dismissed Everett’s theory as "theology," and Wheeler himself was reluctant to challenge Bohr. In a long, political letter to Stern, he explicated and excused Everett’s theory as an extension, not a refutation, of the prevailing interpretation of quantum mechanics.
Everett would have completely disagreed with Wheeler’s description of his opinion of the Copenhagen interpretation.
While Wheeler was off in Europe arguing his case, Everett was in danger of losing his student draft deferment. To avoid going to boot camp, he decided to take a research job at the Pentagon. He moved to the Washington, D.C., area and never came back to theoretical physics.
During the next year, however, he communicated long-distance with Wheeler as he reluctantly whittled down his thesis to a quarter of its original length. In April 1957 Everett’s thesis committee accepted the abridged version - without the "splits." Three months later Reviews of Modern Physics published the shortened version, entitled "‘Relative State’ Formulation of Quantum Mechanics." In the same issue, a companion paper by Wheeler lauded his student’s discovery.
When the paper appeared in print, it slipped into instant obscurity. Wheeler gradually distanced himself from association with Everett’s theory, but he kept in touch with the theorist, encouraging him, in vain, to do more work in quantum mechanics.
As Everett pursued his entrepreneurial career, the world of physics was starting to take a hard look at his once ignored theory. DeWitt swung around 180 degrees and became its most devoted champion. In 1967, he wrote an article presenting the Wheeler-DeWitt equation: a universal wave function that a theory of quantum gravity should satisfy. He credited Everett for having demonstrated the need for such an approach. DeWitt and his graduate student Neill Graham then edited a book of physics papers, The Many-Worlds Interpretation of Quantum Mechanics, which featured the unamputated version of Everett’s dissertation. The epigram "many worlds" stuck fast, popularized in the science-fiction magazine Analog in 1976.
Not everybody agrees, however, that the Copenhagen interpretation needs to give way. Cornell University physicist N. David Mermin maintains that the Everett interpretation treats the wave function as part of the objectively real world, whereas he sees it as merely a mathematical tool. "A wave function is a human construction," Mermin says. "Its purpose is to enable us to make sense of our macroscopic observations. My point of view is exactly the opposite of the many-worlds interpretation. Quantum mechanics is a device for enabling us to make our observations coherent, and to say that we are inside of quantum mechanics and that quantum mechanics must apply to our perceptions is inconsistent." But many working physicists say that Everett’s theory should be taken seriously.
In 1977 DeWitt and Wheeler invited Everett, who hated public speaking, to make a presentation on his interpretation at the University of Texas at Austin. He wore a rumpled black suit and chain-smoked throughout the seminar. David Deutsch, now at the University of Oxford and a founder of the field of quantum computation (itself inspired by Everett’s theory), was there. After the Texas visit, Wheeler tried to hook Everett up with the Institute for Theoretical Physics in Santa Barbara, California. Everett reportedly was interested, but nothing came of the plan.
Personality
Everett’s life was blighted in many ways. He had a reputation for drinking, and friends say the problem seemed only to grow with time. According to Reisler, his partner usually enjoyed a three-martini lunch, sleeping it off in his office - although he still managed to be productive. Yet his hedonism did not reflect a relaxed, playful attitude toward life. John Y. Barry, a former colleague of Everett’s at Weapons Systems Evaluation Group, also questioned his ethics. In the mid-1970s Barry convinced his employers at J. P. Morgan to hire Everett to develop a Bayesian method of predicting movement in the stock market. By several accounts, Everett succeeded - and then refused to turn the product over to J. P. Morgan. Everett had a reputation of egocentric.
Physical Characteristics:
Everett died in 1982 at age 51 of a heart attack and had been in poor health from smoking, drinking and obesity.
Interests
Philosophers & Thinkers
Albert Einstein
Politicians
Harry Browne
Connections
Hugh Everett III married Nancy Gore in 1956, and they had two children, Elizabeth Everett and Mark Oliver Everett (lead singer of the band Eels).
Father:
Hugh Everett Jr.
Mother:
Katharine Kennedy
Wife:
Nancy Gore
Daughter:
Elizabeth Everett
Elizabeth Everett suffered from schizophrenia and committed suicide in 1996, after numerous prior unsuccessful attempts. She left a note saying she was going to join her father in a parallel universe.
Son:
Mark Oliver Everett
Mark Everett became a successful musician with the rock band Eels. It was Mark who discovered his father’s body in bed one morning on July 19, 1982.
