by Peter Byrne
The business of morality
Before coming to Lambda, Reisler worked with “some strange folks” at Research Analysis Corporation, the Army’s non-profit think tank.7 During the Vietnam War, RAC developed psychological warfare techniques under contract to the military.8 “Psy-ops” deals in behavioral patterns: how people think, how they come to believe in political or religious ideologies, how they make decisions. Traditional game theory was useful to psy-ops researchers, until computerized data-gathering took the art of social engineering to a whole new level. Still, the social engineers remained a strange breed within the already strange culture of op research with its custom designed morality.
At Lambda, for instance, Pugh started working on how moral values evolved biologically as algorithmic decision-making processes. After Lambda was folded into GRC, he wrote an important book, The Biological Origin of Human Values.9 Everett and Wheeler were great fans of Pugh’s book, published in 1977. It was praised by Harvard University’s Edward O. Wilson, who was a prime mover in the new science of “sociobiology,” and Pugh became tied to Wilson in the public eye.
Sociobiologists were using information theory and cybernetics to describe and explain the social practices of creatures, from ants to people. But some left-oriented academics attacked the work of Wilson and Pugh as reactionary and classist; unfairly, as it turned out, because theses critics did not grasp that sociobiology actually showed that evolution is wired to favor species-wide altruism and collective action over the “survival of the fittest” individuals,10 which could mean that humans are currently trapped in an evolutionary cul-de sac by industrial and military technology. In his book, Pugh applied concepts underlying Lambda’s targeting software to explain the evolution of morality-based decision-making. For example, targeting programs can be “taught” how best to assign values to targets, and to make decisions that optimize destruction. Taking human survival (not destruction of targets) as a basic biological value, Pugh showed how root emotions of love and fear affect the formation of higher moral values and choices. But he pointed out that biological evolution is relatively slow, and humans have been programmed by evolution to respond to perceived threats hormonally, in hyper-aggressive ways that are not advantageous to living in a modern civilization with its tremendous capacity for instant self-destruction. As a solution, Pugh appealed to “reason,” hoping that humanity’s leaders would (somehow) learn how to curb the inexorable excesses of the capitalist economic system and make political decisions based upon tolerance and love, not greed and fear.
Despite his insight into the nature of morality, and his concern about preprogrammed species-suicide, Pugh used his human values-driven decision-making model to design automated fighting programs for combat aircraft.11
After leaving Lambda, Pugh and Lucas partnered to form their own operations research firm, Decision Science Applications. They successfully used Everett’s magic multipliers in a variety of military and corporate applications. Pugh retired quietly in 1992, and six years later the remaining owners sold the company for $42 million. Lucas walked away a multi-millionaire.
But back to the main story: Even as his Lambda world was collapsing, Everett’s relative states theory, to his surprise and delight, was reborn as the Many Worlds Interpretation of Quantum Mechanics.
BOOK 10
MANY WORLDS REBORN
32 DeWitt to the Rescue
It would be the worse sort of folly to advocate that the study of classical physics be completely dropped in favor of newer theories… Nevertheless, we have a strong desire to construct a single all-embracing theory which would be applicable to the entire universe.
Hugh Everett III, 19561
Many worlds in hibernation
After its publication in 1957, Everett’s theory was officially ignored by mainstream physics for a decade; but his bright idea was not dead, merely hibernating. Science fiction writers set stories inside Everett’s multiple universes. He made a cameo appearance in The Scientist Speculates: An Anthology of Partly-Baked Ideas.2 The book’s editor, a computer scientist named Irving Good, remarked that the notion of multiple universes was the stuff of science fiction until formalized by Everett. He crudely, but correctly summarized the theory as, “We all have innumerable identical twins with whom we very seldom communicate.”3
But as the Xavier conference highlighted, the usefulness of a universal wave function held a powerful attraction for physicists who were dissatisfied with the standard interpretation of quantum mechanics. For instance, in 1963, MIT physics professor, Abner Shimony, published “Role of the Observer in Quantum Theory.”4 He slammed the von Neumann wave collapse postulate as unjustifiably dependent upon the agency of human consciousness. And he expressed disdain for Bohr’s interpretation, saying it abandoned the possibility of understanding the quantum world on its own merits. He concluded that quantum mechanics itself was in need of correction. And in a footnote, he said that the relative state interpretation was deserving of more study. Shimony was motivated to treat the Schrödinger equation as real, but he saw Everett’s model as a violation of Occam’s Razor—the truism that the simplest explanation is the best explanation—by its multiplication of universes. And he left it at that.
In the late 1960s, Deborah van Vechten, a student at Brown University in Rhode Island told her physics professor that she wanted to write her undergraduate thesis on the measurement paradox in quantum mechanics. The professor, Leon N Cooper, was soon to win a Nobel Prize for pioneering work on superconductivity, which is highly quantum mechanical.5 He told her there was “no such thing” as a measurement paradox; and then, “She pushed me on the subject and I realized what I had accepted as the Copenhagen interpretation or the reduction of the wave function was, indeed, paradoxical.”6
Teaming up, van Vechten and Cooper wrote a paper for the American Journal of Physics, “On the Interpretation of Measurement Within the Quantum Theory.” Referring to those who support the Copenhagen interpretation, the authors quoted Spinoza:
They appear to conceive man to be situated in nature as a kingdom within a kingdom: for they believe he disturbs rather than follows nature’s orders.7
Like Everett—of whose theory they were unaware—they attacked von Neumann’s collapse postulate, concluding that it is an “anachronism because it divides mind and body.” Like Everett, they allowed the Schrödinger equation to run its logical course, but they used Feynman’s sum over histories method to support the idea of a non-collapsing wave function that includes the observer.
It was not until DeWitt and Graham asked them to permit their paper to be included in The Many Worlds Interpretation of Quantum Mechanics that Cooper and van Vechten learned of Everett’s theory. They wrote a footnote acknowledging the primacy of his recognition of “the necessity of retaining all branches of the wave function,” with the caveat that of all their possible worlds, only one is real. Cooper was disappointed when he learned that Everett had scooped him; he felt like Augustin Jean Fresnel when he learned in 1816 that his innovative wave theory of light had been previously discovered by Thomas Young.
Cooper remained interested in the measurement paradox,8 writing two more papers on how a branching wave function works. In “How Possible Becomes Actual in the Quantum Theory,” he asserted that the wave function as we perceive it does not seem to contain complete information about the present (as it has branches that we cannot perceive). This makes it difficult to reconstruct the history of the universe. However, the observer may ignore branches that he does not experience because universe-sized probability waves reinforce and cancel each other until one world emerges, “ours.”
We thus have a consistent but curious interpretation—a physical theory in which ‘actuality’ is an outcome of interference between ‘possibilities’—a technical realization of the fantastic vision Jorge Luis Borges presents in The Garden of Forking Paths. Once more the poet has preceded the scientist.9
Enter DeWitt
In 1967, Bryce DeWitt aw
akened the relative state theory from its decade of hibernation. He made it acceptable to talk about multiple universes in public debates. And in doing this, DeWitt stuck his neck out, inviting intense criticism for championing Everett (who remained aloof from the tussle).
More than 30 years later, DeWitt talked about why he chose to promote many worlds. At a symposium, “Science and Ultimate Reality: Celebrating the Vision of John Archibald Wheeler,” he explained that Everett had cut through years of fuzzy thinking about the measurement problem by simply assuming that quantum mechanics replaces classical mechanics as a determinate description of reality:
This is a shocking idea, for it leads to a multiplicity of ‘realities.’ Few physicists in 1957 were prepared to accept it. And yet it can be shown to work.10
Shortly after he died of cancer in 2004, Physics Today published the ailing DeWitt’s farewell to physics, “God’s Rays.” He wrote that if one accepts quantum theory as real, then,
One is obliged to accept a stupendous number of simultaneous realities, namely, all the possible outcomes of quantum measurements as well as all the possible ‘classical’ worlds that emerge spontaneously from the wave function of the universe through the phenomenon of decoherence.11
DeWitt was an early proponent of decoherence theory, which, he thought, describes what happens to the information contained in a wave function as it appears to collapse. He said that the quantum decoherence effect is explained by Everett’s interpretation, which is principally a theory about entanglement.
Bryce DeWitt was born Carl Bryce Seligman on January 8, 1923 in Dinuba, California. His father was a country doctor, and his mother taught high school Latin and mathematics. At age 12, DeWitt was sent off to Middlesex, an academically prestigious boarding school in far-away Massachusetts. On the east coast, he was shocked to encounter social prejudice based purely upon bearing a Jewish last name. Eventually, Seligman and his three younger brothers changed to DeWitt, a surname from their mother’s lineage.
At Harvard University, he majored in physics. During the Second World War, he worked a short time on the Manhattan Project before enlisting in the Navy. After the war, he returned to Harvard and wrote his doctoral thesis on quantizing gravity under Julian Schwinger (a co-inventor of quantum electrodynamics, along with Feynman and Tomanga).
At Princeton’s Institute for Advanced Study he met Cecile Morette, a French physicist, who was soon to found an internationally renowned physics institute in Les Houches, France. In 1951, Cecile and Bryce, now married, resided at the Tata Institute of Fundamental Research in Bombay, India, where the first of four daughters was born. Returning to the United States, DeWitt took a job designing nuclear artillery shells at Livermore National Laboratory in California. The mid 1950s found the couple working as research professors at the University of North Carolina, Chapel Hill where they organized the conference on gravitation, learning about Everett from Wheeler.12
DeWitt recalled his feeling when he first read Everett’s short dissertation in 1957:
First, I was tickled to death that someone had at long last, after so many years and so many tiresome articles, something new and refreshing to say about the interpretation of quantum mechanics. Second, I was deeply shocked.13
He wrote to Wheeler:
It seems to me that the professional philosophers will have a greater appreciation of Everett’s work than will the average physicist, at least for the present. [However] it has become increasingly clear that physicists themselves are obliged to be their own epistemologists, since no other persons have the necessary competence. Therefore Everett’s work is to be praised.14
As previously recounted,15 DeWitt balked at endorsing the full theory, because he could not “feel” himself “split.” But Everett had quickly convinced him that this objection was actually a strength of the theory as it predicted that we will only experience one world, not many. Ultimately, DeWitt, as a cosmologist, was attracted to the universal wave function because a theory of quantum gravity must apply to the whole universe, precluding a role for an external observer.
Enter Graham
In the mid 1960s, one of DeWitt’s graduate students, Neill Graham, wanted to write his PhD thesis on foundations of quantum mechanics. DeWitt tried to discourage him, saying that interpreting quantum mechanics was a topic better suited for old age.16 But Graham persisted and, under DeWitt’s guidance, he explicated the Everett interpretation from his own point of view.
Graham thought that Everett’s derivation of a probability measure from the formalism was inadequate. So, he reworked Everett’s formalism, intent on deriving a different type of probability measure, tantamount to a “principle of indifference.” In doing so, he treated the Everett branches as countable (which Everett did not, he viewed them as uncountably infinite in number). In short, Graham’s universe-counting approach to measuring probability was akin to proposing that as the sun will either explode or not explode tomorrow, the probability of the sun exploding tomorrow is 1/2.17 Everett expressed his pique at Graham’s measure by writing an exclamatory notation of disapproval in the margin of his copy of Graham’s thesis.18 And Graham’s application did not catch on, although DeWitt liked it at first.
Graham also identified, but did not solve, the preferred basis problem.19 This problem has a precise expression in the quantum formalism, but we can capture its philosophical angst in ordinary language. It arises in Everett’s theory because he is not clear on how the classical world of our experience physically emerges from the universal ψ where all physically possible events occur. Why is this world preferred over all of the possible worlds I could find myself inhabiting? Graham asked. How does this moment in time connect to other moments in a causally consistent, finite history set in a coordinate system of infinite dimension? Considering the fuzziness of position and momentum delineated in the uncertainty principle: How does the set of precisely described positions of electrons in this universe connect to the set of precisely described momenta of these same electrons? Can a universe split along a position basis at the same time it splits along a momentum basis? How does a splitting universe choose which basis to split along?
Everett was not particularly troubled by the problem of preferred basis, believing that the selection of a measurement device (for recording position or momentum or spin) automatically determined the basis that describes a connected series of physical events. But it was not until decoherence theory evolved (thanks, in no small part, to Everett’s influence) that the question of preferred basis became less controversial: A quantum system is said to decohere as it interacts with its environment, automatically selecting a causally connected, macroscopic history from the menu of possibilities inherent in its surroundings—while decoupling from those other possibilities. In this scheme, every Everett branch automatically selects a preferred basis as it correlates with an environment at light speed inside the universal superposition, the multiverse.
Banner year: 1967
Graham’s dissertation was not formally accepted until 1970, but DeWitt cited it as an unpublished dissertation in 1967. In the interim, it circulated like samizdat among physicists interested in cosmology. Inspired by working with Graham, DeWitt began publishing papers on the “Everett-Wheeler metatheory” in professional journals—breaking his profession’s silence on the philosophically disturbing idea, while sanctioning it as a viable alternative to the Copenhagen interpretation.
DeWitt published two treatises in 1967 featuring Everett. First came a three-part opus in Physical Review, “Quantum Theory of Gravity,”20 in which he summed up the state of search for a workable theory of quantum gravity. He wrote a section on Everett’s universal wave function, explaining the formal logic of the theory of relative states based upon his reading of the short thesis, as he was not yet aware that there existed a longer, more complete treatise. He was, nonetheless, convinced that Everett had provided quantum mechanics with an internally consistent interpretation, while obviating the need for the wave collapse po
stulate.21
In Physical Review, DeWitt noted,
Everett’s view of the world is a very natural one to adopt in the quantum theory of gravity, where one is accustomed to speak without embarrassment of the ‘wave function of the universe.’22
The concept of a universal wave function was a boon to cosmologists, but it carried philosophical baggage:
Because of the size of the universe, we know that the ‘Everett process’ must be occurring on a lavish scale: … components of the universal state functional must be constantly splitting into a stupendous number of branches, all moving in parallel without interfering with one another … each branch corresponds to a possible world-as-we-actually-see-it.23
That summer, Wheeler and Cecile DeWitt organized a seven-week long conference in Seattle, sponsored by the military contractor, Battelle Memorial Institute. The conference was called Battelle Rencontres, or Battelle “encounter.” The organizers brought together 33 of the world’s leading physicists and mathematicians to ruminate about a wide range of problems, including the quantization of gravity.
DeWitt wrote a paper for the conference, “The Everett-Wheeler Interpretation of Quantum Mechanics.” He defended the relative states model against the charge that the theory violated Occam’s Razor with excessive complexity. He said that, contrary to Bohr’s interpretation, Everett and Wheeler had minimized the concepts necessary to arrive at a workable model of quantum mechanics by treating the wave equation logically and by not resorting to metaphysics. He supported Graham’s derivation of probability by counting universes, (although he was later to change his mind about that approach).