How the Hippies Saved Physics: Science, Counterculture, and the Quantum Revival

by Kaiser, David

  As Ghirardi and Weber tried to clarify their objections to the journal editor, and as Stapp argued with Herbert near Esalen’s hot spring baths, parallel stories began playing out elsewhere. Copies of Herbert’s paper made their way to other little groups of physicists here and there, and a few began to take notice. One copy landed in the hands of Wojciech Zurek and Bill Wootters, two recent PhDs who worked closely with John Wheeler at the University of Texas at Austin. Around the time they finished their PhDs, Wheeler contrasted “the outgoing, ‘take-on-anything’ spirit of Zurek” with the “quieter and more reflective” style of Wootters.59 Together they made a powerful team.

  Zurek and Wootters had been office-mates as graduate students at Austin. They quickly fell under Wheeler’s spell, showing greater-than-average interest in foundational matters.60 After a particularly inspiring visit to Wheeler’s summer cottage in Maine, Zurek enthused, “Every day I come back to the discussions on physics and philosophy we had (always in rooms overlooking the sea!). I often wonder how would contemporary physics look if it were done in the rooms overlooking [the] ocean, and not in [a] ‘publish or perish’ jungle.”61

  Wheeler’s reputation helped to shield the young students from other professors’ disdain for such philosophical patter. Aside from Wheeler’s strong backing, Zurek recalls the general attitude in the hallways at that time: graduate students like himself and Wootters had received “a very obvious and loud message that thinking seriously about foundations was a waste of time and a detriment to one’s career.”62 Nonetheless, Wheeler and his small circle of students soldiered on. Wheeler brought in a steady stream of visiting scholars to keep discussions fresh. He also organized a brand-new seminar on quantum measurement, the mysterious process by which arrays of quantum probabilities get reduced to single, measured results: an entire semester spent puzzling over paradoxes like Schrödinger’s cat.63 Zurek and Wootters polished up a term paper for that class—a fine-grained analysis of the double-slit experiment, calculating precisely the limits and trade-offs imposed by wave-particle duality—and published it in 1979, as one of their earliest forays into the foundations of quantum theory.64 The following year, PhD in hand, Zurek helped Wheeler coteach the seminar. They went on to publish a major collection of articles together, culled from the readings for the class. The mammoth volume, entitled Quantum Theory and Measurement, filled over 800 pages, and quickly became a standard reference. As Wheeler explained soon after the book’s appearance, “Zurek was the brain and dynamo of this enterprise.”65

  How exactly Nick Herbert’s FLASH paper made it onto Zurek’s and Wootters’s desk remains unclear. Certainly Wheeler had been an early and frequent recipient of Ira Einhorn’s mailings, and both Jack Sarfatti and Nick Herbert had long been in the habit of mailing their latest notes and papers directly to Wheeler themselves.66 But Zurek recalls Wheeler keeping “the ‘Californians’” at arm’s length, at least where his students were concerned. The attitude at Austin seemed to have been that it was one thing for an acclaimed physicist like Wheeler to interact with Sarfatti and crew, but quite another for graduate students who were interested in the interpretation of quantum theory to do so. The students already faced an uphill battle among skeptical faculty, and meddling with curious characters outside the mainstream might only exacerbate the situation. Zurek, at any rate, has no recollection of Wheeler passing along papers or preprints by Sarfatti or Herbert to his students.67

  By the late 1970s and early 1980s, however, several other vectors linked Sarfatti, Herbert, and company to Wheeler’s circle. One likely conduit was Larry Bartell, a physical chemist based at the University of Michigan whose scientific interests ranged far and wide. (As Bartell put it recently, a physical chemist is someone who studies “anything that is interesting.”) Much of his research had focused on electron diffraction, in effect conducting real-life double-slit experiments by shooting electrons at crystals and measuring the resulting interference patterns. That work, in turn, had sparked his interest in the foundations of quantum theory. He spent a sabbatical with Wheeler’s group at Austin in the spring of 1978, where he befriended Zurek and Wootters. A few months later, Bartell submitted an article building on Wootters’s and Zurek’s early double-slit paper.68

  At that same time, Bartell also began corresponding with Sarfatti and Herbert; they traded papers and commented on each other’s drafts.69 In the spring of 1980, following another brief visit with Wheeler’s group at Austin, Bartell wrote a longer paper on “concrete new tests” of Bell-styled entanglement. Thanking Wheeler and Wootters for helpful discussions, he closed his article by challenging the superluminal communication schemes of Sarfatti’s 1978 patent disclosure document and Herbert’s 1979 QUICK paper, both of which he had received straight from their authors.70 Bartell remained in touch with Sarfatti and Herbert throughout the early 1980s, and Herbert and Saul-Paul Sirag, in turn, invited him to participate in their February 1983 workshop at Esalen. Bartell still reminisces about his encounters at that “touchy feely place in Big Sur with mixed-sex nude natural baths and natural food.” (“You can imagine it took little persuasion to get people to accept such an invitation to such a pleasant place,” he notes.)71 Meanwhile, Zurek and Wheeler selected one of Bartell’s 1980 articles for inclusion in their Quantum Theory and Measurement volume, which appeared just as Bartell was taking in the delights that Esalen had to offer.72 Still other links—only slightly more attenuated—connected Zurek and Wootters with the remnants of the Fundamental Fysiks Group.73

  Zurek and Wootters shared a hotel room during a small, informal workshop in San Antonio in March 1982 that John Wheeler organized. As Zurek recalls, the informal discussion at the meeting meandered around to a topic that had been on Wheeler’s mind for some time. Wheeler had been seeking some way to dramatize the consequences of Bell-styled entanglement. He was after some way to amplify the effects of nonlocality to a macroscopic scale: to do for Bell’s theorem what his delayed-choice thought experiment had done for the question of quantum measurement. Zurek, meanwhile, had also been ruminating on what might happen if one could amplify an entangled state.74 In his notes from that meeting, he scribbled some questions to himself about whether one could rotate the polarization of individual photons: the selfsame process that had been at the heart of Herbert’s QUICK scheme, as Bartell and Wootters had already discussed in some detail. Not quite two weeks later, Zurek began playing around with the idea of using a laser to amplify an individual photon, such as one member of an entangled pair—the same basic mechanism as in Herbert’s FLASH proposal.75

  With those ideas swirling in his head, Zurek set off for yet another conference. This time it was to Perugia, Italy, for a conference celebrating the ninetieth birthday of Louis de Broglie. De Broglie, a famous architect of quantum theory who had first proposed that wave-particle duality extended to matter as well as light, had long been an outspoken iconoclast when it came to how quantum theory should be interpreted. The birthday meeting in April 1982 featured similar iconoclasts, including Franco Selleri, the Italian physicist who had proposed a superluminal scheme quite similar to Herbert’s QUICK idea back in 1979.76 Since that time, Selleri and Herbert had been corresponding; Selleri even invited Herbert to come visit the group in Bari, though Herbert’s lack of funds scuttled those plans. But Herbert could still afford postage. He had sent Selleri a copy of his FLASH paper, and the two had traded extensive correspondence about it by the time of the de Broglie meeting in Perugia.77 Selleri was besotted with Herbert’s latest proposal, and featured it in his lecture at Perugia. More important, he pushed copies of Herbert’s preprint on several other colleagues, and helped convince an experimental physicist from Pisa to mount a real test of Herbert’s design. The Pisa physicist, in turn, dutifully reported on the early steps of his experiment at the Perugia meeting.78 A graduate student who participated in the meeting later recalled the scene: “People around me were all talking about a ‘Flash communication’ scheme, faster than light, based on entanglement.
”79 Herbert’s preprint had become the talk of the conference. Thanks largely to Selleri’s efforts, references to Herbert’s FLASH paper recur throughout the published proceedings of the meeting.80

  Wojciech Zurek’s research notebook records his impressions of the lectures at the Perugia conference in which Herbert’s scheme had been laid out in detail.81 Thus by April 1982—if not before—Zurek had collided head-on with Herbert’s FLASH design. Immediately upon his return from Italy, Zurek’s thoughts returned to the discussion he and Wootters had shared in their San Antonio hotel room the previous month. He convinced himself that linearity was the key: the linear nature of quantum theory would place the ultimate limit on superluminal signaling, by making it impossible to duplicate arbitrary quantum states. He wrote up a few pages, extending the argument to the general case, abstracting away from details of Herbert’s R, L, H, and V polarization states, and sent them to Wootters to review. Together they clarified that certain quantum states could indeed be amplified, even in the light of linearity. One could design a device that would make perfect copies of a known incoming state or of a state orthogonal to it—replicating states R or L, for example, but then not replicating H and V, and vice versa. What could never be built, at least according to the laws of quantum mechanics, was a device that could make perfect copies of an unknown or arbitrary incoming state. After some minor edits they submitted their paper, under some ponderous (and now forgotten) title, to the American Journal of Physics, a perfectly respectable if less-than-flashy journal.82 (The journal, then as now, focuses on pedagogical matters; it is the forum in which several physicists hashed out their competing schemes for enrolling Fritjof Capra’s The Tao of Physics in the classroom.)

  Luckily for his subsequent career, Zurek also sent a copy of the paper to his former mentor, John Wheeler. Wheeler pressed his young colleagues to aim higher. In particular, he convinced them to take the unusual step of withdrawing their paper from consideration at American Journal of Physics—most likely after it had already been sent out for reviews—and submitting it instead to Nature, one of the world’s leading and most influential scientific journals. More than that, Wheeler lent his famous knack for catchy titles; a decade earlier, for example, Wheeler had coined the term “black hole.” The essence of Wootters’s and Zurek’s argument, Wheeler gleaned, was that “a single quantum cannot be cloned.” With Wheeler’s blessing, Zurek and Wootters chose that exact phrase for the new title of their paper.83 In their now-famous article, Herbert’s FLASH preprint assumes pride of place. Indeed, the very first sentence of Wootters’s and Zurek’s article reads: “Note that if photons could be cloned, a plausible argument could be made for the possibility of faster-than-light communication,” followed by a citation to Herbert’s paper. Wootters and Zurek mailed their paper to Nature in early August 1982, where it sailed through the reviewing process. It appeared in print in late October.84

  Across the Atlantic, while Zurek and Wootters were piecing together their version of the “no-cloning theorem,” Dennis Dieks was following the same series of steps. He had gotten his hands on Herbert’s FLASH paper from a fellow member of a loose, informal discussion group in Amsterdam. Members of the group, who had taken to calling themselves “The Quantum Club,” ranged far and wide. The group consisted of physicists and philosophers, and included everyone from American expatriates who had fled the Vietnam-era draft to eager young Dutch students just finding their scholarly legs. Like Wheeler’s circle in Austin, Texas, the Amsterdam group had been connected to members of the Fundamental Fysiks Group in recent years by sinews like Ira Einhorn’s network and by the Swiss-based newsletter Epistemological Letters.85

  Dieks, a young physicist in Utrecht at the time, recalls that most of his discussion-mates in the Quantum Club were quite taken with Herbert’s argument. Yet something didn’t seem quite right to him. After the discussion had broken up, he continued to puzzle through the argument, and within a few weeks he, too, had isolated essentially the same flaw as Ghirardi, Weber, Wootters, and Zurek had done. Dieks wrote up a brief article laying out the basic critique, emphasizing up front “the crucial role of the linearity of the quantum mechanical evolution laws in preventing causal anomalies.”86

  In Dieks’s paper, Herbert’s FLASH paper assumed an even larger role than in the Wootters-Zurek no-cloning article. Indeed, Dieks’s entire paper revolved around Herbert’s preprint. Other than a citation of Eberhard’s and Ghirardi’s earlier no-go theorems against superluminal signaling, Herbert’s was the only paper that Dieks even mentioned. The citation, meanwhile, betrayed some of the boundedness of Herbert’s circulation scheme. Copies of his papers could travel far and wide, but their meanings or associations did not always stay firmly attached. Dieks cited Herbert’s paper as a preprint from the “National” Science Foundation, missing Herbert’s “Notional” joke entirely.87

  Unbeknownst to all at the time, Dieks submitted his paper to the prestigious Physics Letters journal (based in the Netherlands) exactly one week after Wootters and Zurek sent their paper to Nature, in August 1982. His articulation of the no-cloning theorem encountered a few more bumps en route to publication than Wootters’s and Zurek’s did. Soon after sending his paper off, Dieks learned to his dismay that his enthusiastic pals in the Quantum Club weren’t the only ones who bought Herbert’s argument: so did the referee to whom Physics Letters had sent Dieks’s article. The referee, a fellow Dutchman, went so far as to call Dieks on the phone to explain to him why, based on Dieks’s own description, Herbert’s FLASH scheme would work! Under pressure, Dieks made a few cosmetic changes to his brief paper, and it appeared in Physics Letters in late November 1982, three weeks after the Wootters-Zurek paper had been published in Nature.88

  If GianCarlo Ghirardi had been surprised when his Trieste colleague Tullio Weber had been asked to review Herbert’s revised paper—thinking that he had already killed off the submission a year earlier—a bigger shock was in store for him. One day in April 1983, while flipping through some back issues of journals in the library, he happened to come across Wootters’s and Zurek’s no-cloning article in Nature. (Part of the reason he stopped on that page, Ghirardi later recalled, was the paper’s unusually appealing title.) Skimming the first few paragraphs, Ghirardi knew immediately that the article, which had already been in print for more than six months, contained the same basic argument that Ghirardi had composed for his referee report on Herbert’s FLASH paper two years earlier. Worse still, he noticed from the way that Wootters and Zurek cited Herbert’s paper that “FLASH” had been accepted by Foundations of Physics, and would soon be published!89 (In fact, Herbert’s revised version of “FLASH” had already appeared in the December 1982 issue of Foundations of Physics, though Ghirardi had not caught up on his reading yet.)

  Together with Weber, Ghirardi composed a hasty letter to the editor of Foundations of Physics. “With this letter we want to call your attention to a very peculiar situation,” they began. They reminded the editor of the basic timeline of events, concluding with the latest shockers (publication of Wootters-Zurek in Nature and Herbert in Foundations). “You will understand that we are really upset by this situation,” they continued. The reason for their displeasure is most telling. They were upset, they explained to the editor, because other experts in the field knew that Ghirardi and Weber often acted as referees for Foundations of Physics. Given their earlier published critiques of Herbert’s QUICK scheme, their colleagues would easily surmise that they had been referees of Herbert’s FLASH submission, too. And so Ghirardi and Weber feared that their own reputations were now in danger: others might think that they had failed to find the flaw in Herbert’s latest paper. That would be one insult too many, on top of having been scooped by the Wootters-Zurek paper. Like Wootters and Zurek, who had first submitted their paper to American Journal of Physics, neither Ghirardi nor Weber had any inkling at this early stage that the no-cloning theorem might have any real-world significance. In closing their letter, Ghirardi and Weber
shifted to damage control. “We are then asking you to let us know who is the referee responsible for the acceptance of Herbert’s paper and on what basis the journal has decided to follow his judgment in place of ours. If this point would not be clarified we are not willing any more to act as referees for your journal.”90

  Faced with such a blast, the journal editor took a most unusual step. “In my memory of the 13 years during which I have been associated with Found. Phys.,” the editor began, “this is the first time I have been taken to task by a referee.” The occasion seemed so significant, in fact, that the editor wrote out a lengthy justification of his decision to accept Herbert’s paper. He waved off Ghirardi’s and Weber’s demand to know who the other referees had been—anonymity of referees is considered sacrosanct in academic publishing—but he did share some of the backstory with them. For one thing, he had received written responses on Herbert’s FLASH submission from half a dozen other referees beyond Ghirardi and Weber. To give a flavor of the variety of responses, the editor quoted from several reports, referring to them by number to conceal the reviewers’ identities:

  1) “This is an important result. The article is beautifully written and I recommend its publication.”

  2) “We have not been able to identify any fundamental flaws with the proposed experiment that reveal the origin of the paradox.” (The “we” here are two authors.)