by Peter Byrne
Reiterating that the macroscopic world is “real,” Einstein pondered the inadequacy of complementarity for describing the reality of the microscopic world:
But the “macroscopic” and the “microscopic” are so inter-related that it appears impracticable to give up this program in the “microscopic” alone…. To me it must seem a mistake to permit theoretical description to be directly dependent upon acts of empirical assertions, as it seems to me to be intended in Bohr’s principle of complementarity, the sharp formulation of which, moreover, I have been unable to achieve despite much effort which I have expended on it.20
In his thesis, Everett commented,
Einstein hopes that a theory along the lines of his general relativity, where all of physics is reduced to the geometry of space-time could satisfactorily explain quantum effects. In such a theory a particle is no longer a simple object but possesses an enormous amount of structure (i.e. it is thought of as a region of space-time of high curvature). It is conceivable that the interactions of such ‘particles’ would depend in a sensitive way upon the details of this structure, which would then play the role of the ‘hidden variables.’ … [That] possibility cannot be discounted.21
Wigner’s idealism
Reducing Copenhagen’s emphasis on the role of the observer in quantum mechanics to absurdity, Wigner published a broad attack on scientific materialism in 1961, “Remarks on the Mind-Body Question.” The paper was the product of years of thought and collegial discussion, so his professor’s view that human consciousness rules the quantum world was probably known to Everett prior to its publication.
Citing Descartes’ dictum, “Cogito, ergo sum,” Wigner dealt with the measurement problem by postulating that,
the content of human consciousness is an ultimate reality [and] the question concerning the existence of almost anything (even the whole external world) is not a very relevant question.22
Stating that materialism is incompatible with quantum theory (and all science), Wigner opined that the mind influences the body, but the body does not influence the mind. Defeated, in particular, by an inability to mathematically solve the measurement paradox, Wigner decided that the material world must be purely a product of linked human consciousnesses, which are capable of “modif[ing] the usual laws of physics.”23 Consequently, said Wigner, this “may mean that the superposition principle will have to be abandoned.”24 In the interim, he “solved” the measurement problem by postulating that human consciousness (mysteriously, inexplicably) causes wave function collapse—and that we can determine which physical systems are conscious by determining which cause collapse.
Everett preferred to abandon Wigner’s idealism and keep the principle of superposition. In his thesis, he parodied an element of Wigner’s solipsistic argument, called “Wigner’s friend,” which he labeled “untenable.”
Wigner won the Nobel Prize for Physics in 1963 for contributions to theories of the atomic nucleus (and not for his philosophy of consciousness as determinate of material reality). But his theory of linked consciousnesses continues to be influential. It resurfaced decades later as a “many minds” interpretation of Everett.
Everett’s secret
The last chapter of Jammer’s book concludes with a lengthy exposition of Everett’s “Many Worlds Interpretation.”
According to Jammer,
Everett’s theory was first generally ignored, so much so indeed that a recent reviewer referred to it as ‘one of the best kept secrets in this century.’ The multiuniverse theory is undoubtedly one of the most daring and most ambitious theories ever constructed in the history of science…. It would also imply that all nonmultiuniverse theories, and that is all the other interpretations described in this book, are logically false…. Although quite a few physicists seem to sympathize, though often with reservations, with the principles of the many-worlds interpretation, it can certainly not claim to have gained wide acceptance.25
Jammer covers a large number of interpretations—Copenhagen, orthodox, hidden variables, stochastic, statistical, axiomatic, quantum logical, etc. We have looked at only the interpretive models that Everett commented upon. But he had a deep scientific literature to draw upon, and he was talking to some of the cleverest minds in the physics of his day. He was rather well-informed when he decided that,
The wave function itself is held to be the fundamental entity, obeying at all times a deterministic wave equation…. The wave theory is definitely tenable and forms, we believe, the simplest complete, self-consistent theory.26
BOOK 4
EVERETT AND WHEELER
13 Wheeler: the Radical Conservative
[There is a] widely held idea that we are distinguished from most periods of history by our greater realism. But to speak of our realism is almost like a paranoid distortion. What realists, who are playing with weapons which may lead to the destruction of all modern civilization, if not of our earth itself! If an individual were found doing just that, he would be locked up immediately, and if he prided himself on his realism, the psychiatrists would consider this an additional and rather serious symptom of a diseased mind.
Erich Fromm, 19551
I personally regard the hydrogen bomb, dreadful though it will be if ever used, as the policeman’s stick that enforced the long peace of this era.
John Wheeler, 19982
John Archibald Wheeler was born into a family of librarians in 1911. He died almost 97 years later, after a long, successful career in nuclear and particle physics, general relativity and quantum physics. He was an accomplished teacher, lecturer, and author of technical books, as well as many essays linking science and morality. He was also a enthusiastic designer of nuclear weapons. His obituary in The New York Times spoke of these achievements and named his two most prominent students (both of whom pre-deceased him): the Nobel Prize-winning Richard Feynman, much-loved and lionized in life, and Hugh Everett III, who died in relative obscurity.3
Wheeler would undoubtedly have been pleased to be associated in death with Feynman, whom he had mentored and collaborated with on important work; but he might have felt less than cheery about having Everett’s name carved on his media tombstone. Their quarter century relationship was troubled from the start. As Everett’s scientific mentor, Wheeler was forever of two minds about the importance of the many worlds theory. He initially championed it to his own mentor, Bohr, and later publicly disavowed it, but he could never let go of it entirely.
Cecile DeWitt-Morette remembered conversations between her late husband, Bryce S. DeWitt, and Wheeler regarding the pros and cons of publishing Everett’s controversial dissertation in Reviews of Modern Physics in 1957:
I am going to be blunt. Wheeler is a great person, but his total admiration for Bohr was so ingrained in the man, that you do not have any idea what it was like. So, when he first saw the Everett paper, he was actually very uncomfortable because it was questioning Bohr. On the other hand, he wanted to be friendly with everybody. And in case that paper would have an important impact in the future, he did not want to oppose it, but in his heart of hearts he was really uncomfortable with anybody questioning Bohr.4
Two years before he passed away at his home in Hightstown, New Jersey, Wheeler said, “How I wish I had kept up the sessions with Everett. The questions he brought up were important. Maybe I did not have my radar operating.” When asked why Everett’s theory was not well-received at the time of its publication in 1957, Wheeler replied, “Because it made no clear and verifiable predictions.” When asked if Everett was disappointed, Wheeler remarked, “He was disappointed, perhaps bitter, at the non-reaction to his theory. I’d love to talk to him today and get his answer to this question. I’d love to have a nice long talk with him today.”5
John Wheeler with busts of Einstein, Bohr, circa 2003.
As an “original” man, Everett had epitomized the clever young scientist that the professor was constantly looking to recruit to work in advanced weaponry research for the government
and its defense contractors. But more than that, Wheeler admired Everett’s general brilliance; he was disappointed that the young man abandoned physics research after his theory was rejected by Bohr. For nearly a quarter century, Wheeler tried to bring him back into the academic fold, convinced that Everett had significant contributions to make beyond his initial foray.
In 1998, Wheeler published an autobiography, Geons, Black Holes & Quantum Foam, co-written with Kenneth Ford, his former student and long time colleague. Geons is an informative trip through the nuclear bomb-laden landscape of 20th century physics. And it is a remarkably candid account of Wheeler’s fascination with fascism and related methods of social control. The few paragraphs he devotes to Everett, however, do not even begin to tell the whole story of what happened between them. To understand Everett—we must get to know Wheeler.
Nuclear physics comes of age
Growing up in Youngstown, Ohio during the Roaring Twenties, Wheeler enjoyed a Norman Rockwell-type of upbringing; he was happy, patriotic, eager to please. From an early age, he was curious about technology, especially related to things that go bang!, mangling his hand as a teenager while experimenting with dynamite caps. At the age of 15, Wheeler enrolled in John Hopkins University, originally majoring in engineering. But he quickly found his vocation in the brave new world of quantum physics, then centered in Copenhagen and GÖttingen, Germany.
In 1933, he received a doctorate in theoretical physics from Johns Hopkins for research on the structure of the helium atom. With a scholarship from the Rockefeller Foundation’s National Research Council, he spent a year as a post-doc at New York University doing nuclear physics with a pugnacious Russian émigré, Gregory Breit—an experimentalist and first-rate theoretician. “Regrettably, [Breit] was a heavy smoker, but in those days one put up with it. He also had a habit of snorting every once in a while like a bull about to charge,” the non-smoking Wheeler recalled.6
The next year, it was off to study the atomic nucleus with Bohr in Copenhagen (supported by more Rockefeller money). At the Institute, Wheeler felt like he had joined an “international family” of physicists, with the smoke-wreathed, pacing Bohr assessing the worth of quantum mechanical conjectures by whether or not they fit his dualist model of reality, complementarity. “Breit taught me new mathematical and calculational techniques. Bohr taught me a new way of looking at the world,” said Wheeler.7 Indeed, he adopted many of his mentor’s mannerisms (drawing the line at smoking); particularly his oracular style of speaking about physics. Returning to the United States, Wheeler became one of complementarity’s strongest advocates, despite feeling (at least, in retrospect) “uneasy” about its explanatory gaps.8
John Wheeler, 1934, Copenhagen.
At Bohr’s institute, Wheeler became friendly with Heisenberg, who, a few years later, ran the Third Reich’s atomic bomb research program.
In our talks, he tried to steer clear of politics. Always circumspect, he neither praised not condemned Hitler. He was a patriot…. I felt sympathy for him. I could understand his commitment to his country. In science, Germany led the world. In culture and arts, it had a centuries-long record of achievement. I was inclined to believe, as he no doubt did, that an immoral dictatorship was a transitory evil, something a great nation could endure without lasting harm. Of course, I was wrong.9
Marrying Janette Hegner in 1935, Wheeler accepted an assistant professorship in physics at the University of North Carolina in Chapel Hill. Exploring the atomic nucleus, he developed an important method—called a scattering matrix—for analyzing the probabilities of radioactive events. But North Carolina was not Princeton: the powerhouse of theoretical physics in America.
Fortuitously, in 1938, Wheeler was invited to join the Princeton faculty. Settling into a wood-paneled office in Fine Hall, he groomed like a business man complete with tightly knotted tie and starched cuffs.10 Radical in his physics, but deeply conservative in his politics, he looked forward to tea-times, when he could commune with similar souls, von Neumann, Wigner, Wolfgang Pauli, Hermann Weyl.11
Next door to Fine Hall was Palmer Physical Laboratory: a large building filled with chemical equipment, machine shops for making high-voltage electrical devices, and a laboratory capable of lowering the temperature of atoms until they slowed enough to be observed and controlled. The lab’s pièce de résistance was a cyclotron that accelerated and collided particles, so that the pattern of their scatter revealed rules of nature.12
In January 1939, Wheeler met Bohr’s arriving ocean liner in New York Harbor. The great man of physics, accompanied by his loyal assistant, Rosenfeld, bore news of import: Otto Frisch, of Bohr’s institute, and his aunt, Lise Meitner, had correctly analyzed the result of a radiation experiment performed by two German chemists. They had concluded that uranium atoms will split when bombarded with neutrons. Excited, Wheeler and Bohr immediately went to work modeling exactly how the heavy atom’s nucleus, visualized as a liquid droplet could bisect, or split. Their work led to the fissioning of a rare isotope, uranium 235, and also of a new element, later called plutonium. Atomic fission of these metals set off a chain reaction, unbinding the explosive energy that fuels the stars.
Wheeler and Feynman
Shortly before the Japanese attack on Pearl Harbor, Wheeler’s graduate student, Richard Feynman, came to him with the kernel of a grand idea that he called “path integrals.” Feynman treated the possible paths of a particle as probability waves (wave functions) that can reinforce or cancel each other. In this model, the actual trajectory taken by a particle is the “path of least action,” or the sum of all the possible paths it could take—a “sum over histories.” After adding and subtracting the wave functions of these superposed, not-yet-real trajectories, the path left standing is the most probable path, the track we would see in a cloud chamber. The paths taken by particles as they scatter off or absorb each other—transforming, thereby, into different kinds of particles—can be expressed graphically by the diagrams that bear Feynman’s name. By the end of the 1940s, the splitting and merging patterns revealed by Feynman diagrams allowed physicists to visualize quantum interactions for the first time.
Wheeler often co-authored papers with his students. And he was a sounding board for Feynman during the several years it took for him to work out the substance of his thesis on path integrals. The new theory laid out many of the basic ideas of modern quantum electrodynamics, which applies to particles moving at near light speeds, taking into account relativistic effects, such as different time frames for different velocities. But, in the end, Wheeler was ditched by the smartest student he ever had. As James Gleick reported in his biography of Feynman, Genius, “[Feynman] took pains to leave his collaboration with Wheeler decisively behind. He wanted his thesis to be his own.”13 Wheeler later said that working with Feynman was one of the “most satisfying” events in his life.14 In 1965, Feynman shared the Nobel Prize for Physics with Julian Schwinger and Sin-Itiro Tomonga for developing quantum electrodynamics.
Wheeler, however, never received a Nobel Prize, (although he was awarded dozens of honors, and was a VIP in the most exclusive and prestigious scientific organizations). Nonetheless, the moral and intellectual support that he tendered to Feynman’s and, later, Everett’s bright ideas, were major contributions to physics.15
War comes to Princeton
Although he was a flexible and creative physicist, Wheeler had an inflexible, “might-is-right” attitude when it came to politics and warfare. Before Pearl Harbor, he was oft-criticized by his more liberal colleagues as a Nazi-sympathizer, which he was, and which he lived to regret. He later explained,
In the months before Pearl Harbor [while Hitler was crushing Eastern Europe and invading France and Russia], we had a radio in the Fine Hall Tea Room so that we could listen to the war news and discuss the war’s progress. I reached the conclusion that a German-dominated Europe might be the best way to assure long-term peace in Europe…. I admired the strength and efficiency of the German state. I
cannot claim to have been a naïve young man out of touch with the real world, for I had been avidly interested in history and foreign affairs since my student days. I had learned from German Jewish scientists … what a threat they considered Hitler’s Germany to be…. I discounted the fears of my friends, believing that no civilized people could translate poisonous rhetoric into inhuman action…. This sympathy did not vanish instantly when America entered the war. It evaporate slowly as I learned more. Even when I was doing everything I could to help defeat Germany, I clung to the belief that people are fundamentally decent everywhere, that German atrocities were as unthinkable as American atrocities…. But not until I visited Auschwitz in 1947 was the full horror of German barbarism brought home to me.16
On December 7, 1941—despite the existence of military intelligence showing that the attack was imminent—Japanese airplanes sank American warships in Pearl Harbor. The American populace, which had been reluctant to become involved in another world war, instantly mobilized. Fueled by military funding, industry and science supercharged each other. For his part, Wheeler joined the Manhattan project. From 1942–1945, he worked out how to manufacture plutonium as a byproduct of nuclear reaction in concert with the Du Pont Company and the Metallurgical Laboratory at the University of Chicago. Plutonium was the fissionable material at the core of “Fat Man,” the atom bomb that annihilated Nagasaki on August 9, 1945.
