How the Hippies Saved Physics: Science, Counterculture, and the Quantum Revival
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The lean years brought new opportunities for some, including laser physicist and former Stanford lecturer Harold Puthoff. Puthoff had previously worked as a naval intelligence officer and a civilian researcher at the National Security Agency. He completed his PhD at Stanford in 1967 on a new type of tunable laser, and stayed on for several years to teach in Stanford’s electrical engineering department, where he coauthored a textbook on quantum electronics. He joined SRI in 1969 and left the university the following year, when SRI was spun off; in short order his laser-research government contracts began to deflate. With time on his hands, he asked his SRI supervisor for permission to begin conducting a different set of experiments: tests of parapsychological effects. Puthoff was a devotee of Scientology at the time, a controversial set of beliefs that centers on mystical connections between mind and body. He had also dabbled in early rumblings of the California New Age scene during the 1960s, including workshops on gestalt therapy and consciousness expansion. Puthoff secured a grant from a private philanthropist who had made his money in the fried chicken business; with a check for $10,000 (more than $50,000 in 2010 dollars), he was up and running. He courted another laser physicist from Sylvania’s research laboratory, Russell Targ, who had done some graduate-level work at Columbia but left before completing his PhD. Targ, too, had begun to sample some of the New Age offerings around the Bay Area. Together, Puthoff and Targ jumped into the psi business.12
Their big break came in September 1972, when the Israeli performer Uri Geller visited SRI to conduct laboratory tests of his psychic abilities. Geller claimed not only clairvoyance—the ability to read minds or receive signals from the future—but psychokinetic powers as well. His most famous feat: bending metal objects, such as spoons and keys, by focusing psychic energy in his fingers. Puthoff and Targ’s psi lab at SRI, already up and running by the time promoters had brought Geller to the United States, seemed the perfect place to put Geller’s powers to the test. Weeks of close observation ensued; hours of film were shot. Puthoff and Targ concluded that Geller had indeed demonstrated parapsychological abilities, such as reproducing drawings that had been sealed in an envelope, or guessing correctly—eight times in a row—the number on a die contained within a steel box.13
Even before the physicists at the Stanford Research Institute began to publish their results, their research started to make headlines around the Bay Area and beyond.14 Thus it was that Sarfatti happened upon the newspaper article about their work in the summer of 1973, just a few weeks before he was to leave for Italy. Intrigued, he called SRI, was connected to the Electronics and Bioengineering Laboratory (as Puthoff and Targ’s psi lab was called), and invited to come and see for himself. He spent a marathon day at the lab, seventeen hours in all, during which he met Puthoff and Targ as well as paranormal enthusiasts Brendan O’Regan and Edgar Mitchell, the latter a former astronaut who conducted telepathy experiments with friends on Earth while he orbited the moon during the Apollo 14 mission of February 1971. (Upon his return to Earth, Mitchell founded the Institute for Noetic Sciences in Palo Alto, California, to support parapsychological investigations; his institute had helped to bankroll Geller’s visit to SRI in 1972.)15
Not long after Sarfatti’s day-long visit at SRI, one of Uri Geller’s close associates, the medical doctor and parapsychologist Andrija Puharich, published an admiring biography of Geller, entitled simply Uri. Puharich gave a copy to Sarfatti, who in turn loaned it to his mother. The book, combined with Sarfatti’s recent introduction to Geller’s feats at SRI, triggered a momentous shift in the young physicist. Puharich asserted in the book that Geller had received repeated telephone calls from a robotic-sounding voice that called itself “Spectra.” The voice claimed to be an extraterrestrial computer orbiting the earth, contacting a small group of select individuals to help prepare for future contact. Upon encountering that passage, Sarfatti’s mother told Jack that he, too, had received such telephone calls twenty years earlier, at the age of thirteen. The young Sarfatti had ignored, forgotten, or repressed all memory of the strange calls until his meeting with Puthoff and Targ, and his mother’s reading of Puharich’s book, brought it all screaming back to consciousness. From that point on, there was no going back: Sarfatti threw himself into the strange world of psi.16
During Sarfatti’s first visit to the Stanford Research Institute psi lab, Brendan O’Regan had asked Sarfatti if he could introduce Geller to some of the European physicists whom Sarfatti was about to visit, so that the scientific tests could continue. Once Sarfatti joined his friend and San Diego State physics colleague Fred Alan Wolf in London a few months later, the two did just that. Their case was helped by Geller’s own promoters, who had managed to book Geller on a live British Broadcasting Company television show in November 1973. A London-based mathematical physicist participated in the broadcast and declared Geller’s feats to be genuine psychokinetic effects, in need of explanation from the world’s physicists. By February 1974, with Wolf’s and Sarfatti’s help, renowned physicist and hidden-variables expert David Bohm and a colleague at London’s Birkbeck College had made contact with Geller and begun their own series of investigations, which would stretch over the course of the next year. (Bohm’s colleague, an experimental physicist, had arranged Wolf’s invitation to Birkbeck.) Sarfatti was in London during one of their sessions with Geller that June, and he dashed off a detailed press release. Not only had Geller again managed to bend metal objects (including, this time, one of Bohm’s own keys), but he also produced a burst of radioactivity, from no known source, that sent a Geiger counter held in his hand clicking up to 150 times per second. The next day, Geller repeated the Geiger counter burst and bent the house key of skeptical observer and famous science-fiction author Arthur C. Clarke, while Clarke, Sarfatti, Bohm, and others looked on.17 (Fig. 4.2.)
The results seemed clear. “My personal professional judgment as a PhD physicist,” Sarfatti closed his press release, “is that Geller demonstrated genuine psycho-energetic ability at Birkbeck, which is beyond the doubt of any reasonable man, under relatively well controlled and repeatable experimental conditions.” Bohm and his Birkbeck colleague agreed, publishing an account of their investigations in the top-flight scientific journal Nature. They urged caution against runaway theoretical speculations, arguing that (as in the early stages of any scientific field) it was most important to establish a baseline of reliable empirical observations first. Sarfatti had a different idea. To him, the Geller tests forced physicists to return to the foundations of quantum mechanics. “The ambiguity in the interpretation of quantum mechanics,” Sarfatti argued, “leaves ample room for the possibility of psychokinetic and telepathic effects.” Most important, he elaborated, was the “intrinsically nonlocal” character of quantum theory. Drawing on a preprint of Bohm’s own latest grapplings with Bell’s theorem and nonlocality, as well as intriguing ideas from such giants of the discipline as Eugene Wigner and John Wheeler, Sarfatti argued that consciousness need not be separate from brute matter. Sarfatti maintained that quantum mechanics, properly understood, could provide a mechanism to account for psi effects like those exhibited by Uri Geller.18
FIGURE 4.2. Physicists tested the psychic abilities of Israeli performer Uri Geller, first at the Stanford Research Institute in California (left) and later at Birkbeck College in London (right, with physicist David Bohm). (Photographs by Shipi Shtrang, courtesy Shipi Shtrang and Uri Geller.)
A decade earlier, in an admittedly speculative move, Princeton’s Nobel laureate Eugene Wigner had proposed that consciousness plays a central role in quantum mechanics. Left on its own, the quantum formalism seemed to imply an infinite regress of probabilities: an electron had a certain probability to be spin up or spin down; a detector had a certain probability to measure the particle’s spin as being up or down; the detector’s needle had a certain probability to point toward “up” or “down” on its display screen; and so on. This had become known as the “measurement problem” of quantum mechanics. What
if, Wigner wondered, the consciousness of a human observer were the only thing that could break the regress and register a definite response: spin measured as up or down?19
Wigner introduced a simple thought experiment, often referred to as “Wigner’s friend,” to motivate his conclusion. Imagine that instead of conducting the spin measurement on the electron yourself, you ask a friend to do so. Until you interact with your friend by asking her what the measured outcome was, the best you can do is represent the total system—electron plus measuring device plus friend—by one quantum wavefunction. As far as you are concerned, when you ask your friend for the outcome, she will have a certain probability of responding “spin up” and a certain probability of responding “spin down.” After the dust has settled, Wigner pressed on, you might go back and ask your friend, “What did you feel about the spin-measurement outcome before I asked you?” No doubt your friend would respond, “As I already told you, it was spin up (or spin down).” That is, as far as your friend is concerned, the outcome had already been settled before you bothered asking the question. Or, in quantum-mechanical parlance, the wavefunction for the system had already settled into one of its two possible states: electron spin up and friend in the state “I have measured the electron to be spin up”; or electron spin down and friend in the state “I have measured the electron to be spin down.” That was her version of the wavefunction prior to your asking your question; yet your own version of the wavefunction was still stuck in a superposition of both possibilities. To Wigner, there could only be one proper wavefunction for the system—meaning that your friend’s consciousness had already changed (or “collapsed”) the wavefunction from a sum of possibilities to one definite outcome, even before you asked her about it. If you didn’t believe that—if you clung to your own version of the wavefunction after her measurement was complete but before you asked her the outcome—then, feared Wigner, you would be forced to the “absurd” conclusion that your friend was “in a state of suspended animation” before she answered your question: caught, like Schrödinger’s famous cat, between two irreconcilable states. Such suspensions were bad enough when attributed to cats; they simply would not do when applied to tenured professors at Ivy League institutions. “It follows,” Wigner concluded, “that the being with a consciousness must have a different role in quantum mechanics than the inanimate measuring device.” Or, more strongly: “Consciousness enters the [quantum] theory unavoidably and unalterably.”20
Such talk stood out starkly from the pragmatic concerns with which most of Wigner’s colleagues occupied themselves at the time. He came by it honestly. The Hungarian-born physicist had been trained on the Continent between the world wars; as a student, he had heard Einstein, Heisenberg, and others lecture on the still-new quantum mechanics. Years later, his philosophical interests were rekindled when he took on Abner Shimony as a graduate student at Princeton. (Shimony, recall, later worked with John Clauser to rederive Bell’s theorem in a form suitable for laboratory test.) Shimony came to Wigner directly from his own PhD in philosophy at Yale. From that time forward, Wigner devoted more and more of his attention to the foundations of quantum mechanics, corresponding frequently with pockets of physicists in Europe who chased these questions throughout the 1960s.21
Wigner soon acquired an interlocutor closer to home. His friend and Princeton colleague John Wheeler picked up on the theme of consciousness and quantum mechanics during the early 1970s. Wheeler, too, stood out from the pack. An American, he had come of age in the 1920s and 1930s, a time when Americans who wanted to become theoretical physicists still had to travel to Europe to “learn the music, and not just the libretto” of work in that field, as one of Wheeler’s contemporaries famously put it.22 Wheeler studied with Niels Bohr in Copenhagen in the 1930s and often hosted his mentor during Bohr’s many extended visits to Princeton after the war. These contacts helped to stoke Wheeler’s continuing philosophical engagement with quantum theory. Spurred further by Wigner’s efforts, Wheeler emerged, by the mid-1970s, as one of the few leading physicists working in the United States who took the interpretation of quantum mechanics seriously.23
Wheeler argued for a view that he came to call the “participatory universe”: observers participate in creating the reality they measure. As Wheeler argued, a physicist’s decision to measure a particle’s position rather than its momentum changes the objective properties of the real world. Wheeler emphasized the point at a conference at Oxford early in 1974. Quantum theory, he stipulated,
demolishes the view we once had that the universe sits safely “out there,” that we can observe what goes on in it from behind a foot-thick slab of plate glass without ourselves being involved in what goes on. We have learned that to observe even so minuscule an object as an electron we have to shatter that slab of glass. We have to reach out and insert a measuring device. We can put in a device to measure position or we can insert a device to measure momentum. But the installation of the one prevents the insertion of the other. We ourselves have to decide which it is that we will do. Whichever it is, it has an unpredictable effect on the future of that electron. To that degree the future of the universe is changed. We changed it. We have to cross out that old word “observer” and replace it by the new word “participator.” In some strange sense the quantum principle tells us that we are dealing with a participatory universe.24
To drive the point home to his physicist colleagues, Wheeler included a cartoon contrasting the old notion of an “observer” with his new idea of a “participator”—a cartoon he inserted into other conference talks over the next few months.25 (Fig. 4.3.)
FIGURE 4.3. Princeton physicist John Wheeler’s cartoon version of the difference between the “old concept of the ‘observer,’” and the “new concept of ‘participator’” as required by quantum mechanics. (Patton and Wheeler [1975], 563. Reproduced with permission of Oxford University Press.)
Wheeler had grand ambitions for these “participators.” Not only did they fix the reality of the here and now; they could even do so retroactively. Wheeler returned to that old standby of quantum theory, the double-slit experiment, and gave it a new twist. Suppose, he argued, that the photographic plate behind the slits were mounted on a pivot. In one position, the plate would sit smack in the path of any particles that traversed the slits, thereby registering the familiar interference pattern. In another position, the plate could be swung clear of the particles’ paths, so that they bypassed the plate altogether. In this second setting, the particles would continue on their way and encounter one of two sensitive detectors: one placed to detect only those particles that had traveled through the top slit, and the other placed to detect only those that had traveled through the bottom slit. Next the participator could tune down the intensity of the particle source so that only a single quantum was released at a time. The participator now had a choice. Insert the photographic plate into the particle’s path and observe the famous quantum interference pattern—which could only arise if each particle effectively went through both slits at once. Or remove the photographic plate and let the detectors determine whether a given particle had traveled through the top or the bottom slit. But here’s the rub: the participator could decide to insert or remove the photographic plate after the particle had already passed through the slits! (Fig. 4.4.) Wheeler dubbed such scenarios “delayed-choice” experiments: a “last-instant free choice on our part,” he explained, “gives at will a double-slit-interference record or a one-slit-beam count.” The lesson? “The past has no existence except as it is recorded in the present…. The universe does not ‘exist, out there,’ independent of all acts of observation. Instead, it is in some strange sense a participatory universe.” Not everyone was pleased with Wheeler’s conclusion. Some anonymous reader highlighted this passage in the MIT library’s copy of the conference proceedings, adding in the margin simply, “ugh.”26
Wheeler still wasn’t done. One could replace the benchtop apparatus of particle source, double-slit, and
swiveling photographic plate with a cosmic substitute. Consider, he pressed on, streams of light impinging on an earthbound participator from a faraway quasar, an intense astronomical light source billions of light-years away. In between the quasar and the Earth lies a galaxy, massive enough to bend the light’s path and thus act as a “gravitational lens.” (At the time Wheeler was writing, astronomers had recently identified just such a quasar-galaxy pair.) Some quanta of light, or photons, would travel directly from the quasar to Earth; others would travel a more circuitous route, starting off in a direction away from the Earth but getting bent back toward the Earth by the intervening galaxy. Now repeat the delayed-choice setup: by suitable arrangement of photographic plates and sensitive detectors, the participator could decide to measure by which route an individual photon traversed the cosmos (direct or via the path-bending galaxy); or she could decide to measure the quantum interference that comes from traversing both paths. “But the photon has already passed that galaxy billions of years before we made our decision.” It was as if “we decide what the photon shall have done after it has already done it”—in this case, not microseconds before we make our choice, but billions of years before. Indeed, Wheeler emphasized, our decisions today can determine the past of a particle that was emitted long before there was even life on Earth.27