11 Stigma
One day in his office at CERN Bell was visited by a young physicist who told Bell that he was gearing up to do an experiment based on Bell’s Theorem.
“Do you have a permanent position?” was Bell’s response.
It was a joke—but only something of a joke. Bell knew all too well, indeed from personal experience, that there was a stigma attached to doing such work. Bell’s stature in the field was secure, but that of his visitor was not: the proposed experiment was to count toward his PhD dissertation work. Bell knew that the young man was taking a risk, for his experiment would take place amid a general atmosphere of indifference.
Not for eight years after his groundbreaking discovery was the first experiment conducted to test Bell’s result. And not for seventeen years was the second set of experiments performed. That does not exactly add up to a burst of excited attention. The same pattern is found in the attention paid by other scientists to the article in which Bell announced his discovery. Most important discoveries in science are greeted by an immediate and intense burst of interest. In contrast, Bell’s was greeted with a near-complete disinterest. Hardly anyone paid any notice. It was only slowly, over a period of more than a decade, that attention to his theorem slowly built up.
This indifference was part of a wider pattern. Perhaps my own testimony will be illuminating here. I was certainly aware, in a vague way, of Bell’s result in those days. But I paid it little attention. Why? Had you been there to ask me, I would have said that it was simply because I was busy with other things.
And to be honest, this is a perfectly valid response. At every stage of one’s life, there are a few things that one is doing, and there is a well-nigh infinite number of things that one is not doing. By now I find myself fascinated with Bell’s work and its implications—but, by the same token, I am not working on the composition of the rings of Saturn, or the origin of the moon, or the nature of quasars. There are only so many hours in the day.
Looking back on my career, it seems to me that many times my choice of what to work on has been influenced by what everybody else was working on. If everybody in my field was fascinated by such-and-such an issue, then I was likely to be too. And usually that issue was indeed fascinating, and worthy of attention—and indeed, much fine work was being done on it, and many wonderful results obtained. Why turn one’s back on all this good stuff? Why spend time way off in the boondocks, working on an issue that nobody else cared about?
But in the end I cannot say that I find any of this fully persuasive. None of it really accounts for the great silence that greeted Bell’s work. There was a near-total lack of interest, a well-nigh universal shrug. Was it all just a matter of fashion, of the style of work people prefer to do? (The reader may be surprised to read of fashion playing a role in science. And of course it has no place if we are speaking of its dictating the results of scientific research: the physical universe is not a matter of opinion or taste. But it is another matter entirely if we are speaking of the choice of what research to conduct.)
Why did the great mystery, which so engrossed the founders of quantum mechanics, simply seem to pass out of fashion for so many years?
Part of the reason was John von Neumann.
Von Neumann was a mathematician, one of the most prestigious of his age. Born in Hungary to wealthy parents—his father, a banker, was elevated to the nobility—he was raised in an 18-room apartment on the top floor above the multigenerational family business. There, his parents realized that they had a child prodigy on their hands. By the age of six he was doing the sort of arithmetic that the rest of us would find hard on paper: he was doing it in his head. Within two years he had learned calculus. At 15 he began private studies with a prominent mathematician who found himself blinking back tears on encountering so prodigious a talent. By his late twenties he had published 32 major scientific papers, at the rate of nearly one a month.
This extraordinary genius was no recluse. He loved the good life. He appreciated food (his wife joked that he could count everything except calories) and drink and conversation. And he loved clothes. Invariably dressed formally, he was so elegant that one of his teachers inquired at his doctoral exam “Pray, who is the candidate’s tailor?” He did his best work surrounded by cacophony, and at his office would regularly blast loud German march music out on his phonograph. He was a ghastly driver.
Von Neumann’s fellow mathematicians were frankly astounded at his talent. One, whose lectures von Neumann attended as a student, said that he “was the only student I was ever afraid of.” He made seminal contributions over an extraordinarily wide swath, ranging from the foundations of mathematics all the way up to game theory and economics. He worked on weapon design—he took part in the Manhattan Project, which developed the atomic bomb, and he contributed to the design of the hydrogen bomb.
And he worked on quantum theory.
In 1932 von Neumann published a book entitled Mathematical Foundations of Quantum Mechanics. It was a hugely influential work—a work of which he himself was quite proud. And in that work he proved—proved mathematically, proved rigorously, and without a shadow of a doubt—that hidden variables had no place in quantum mechanics.
My guess is that many physicists found themselves positively relieved at this result. If there is one thing that the ongoing argument between Bohr and Einstein proved, it is that the question of the interpretation of quantum mechanics is hard—very hard. And now one of the most famous mathematicians in the world had relieved them of the burden of carrying on the task. There were no hidden variables. Quantum mechanics was not half a theory. It was a full theory.
There was only one problem. Von Neumann’s proof was only a “proof.” It contained an error.
But the error was subtle and it eluded people for decades. During the intervening period, everyone thought that the problem had been solved. It was only years later that the error was discovered.a
So it is a complicated story. For decades physicists found themselves free to ignore the historical argument that had once raged over the nature of quantum reality. Since they felt they did not have to deal with it, they did not deal with it. So there was plenty of reason for these matters to be relegated to the sidelines.
But I believe there is more to the story than this. Because I believe it was not just a matter of indifference. It was a matter of scorn. I think that discussion of the subject was greeted in those days with an active antipathy. Look, for instance, at where Bell had chosen to publish his result. Avoiding all the mainstream journals, he had placed it in a new and obscure journal, one that promptly went out of business. Why did Bell hide his great discovery away like this? Why was he worried? I’d say he was worried because of the stigma. At the time, Bell was on sabbatical leave, and he apparently felt uncomfortable asking his host institution to pay the cost of publishing anything on so outlandish a topic. Most scientific journals support themselves financially by assessing authors a fee to cover the cost of publication: these fees can be quite steep. So he chose to publish in one of the few journals that did not levy these charges.
What had changed from the days of the Bohr–-Einstein debates to this?
The historian of science David Kaiser attributes this shift in attitude to the cataclysm of World War II and the exigencies of the Cold War. Federal funding for physics shot up enormously during the war—by a factor of over 50 within a mere seven years. Such a flood of money was bound to have a transformative effect on the field.
The annihilation of Hiroshima and Nagasaki forever altered the status of physics in the eyes of the world—and in the eyes of physicists too. Once gentle souls, lost in their ivory towers, physicists suddenly found themselves acting more like hard-nosed captains of industry. Once they were philosophers, now they were warriors:
Before the war, Einstein, Bohr, Heisenberg, and Schrödinger had held one model in mind for the aspiring physicist. A physicist should aim, above all, to be a Kulturträger—a bearer of culture—as comfortable reciting passages of Goethe’s Faust from memory or admiring a Mozart sonata as jousting over the strange world of the quantum. The physicists who came of age during and after World War II crafted a rather different identity for themselves. Watching their mentors stride through the corridors of power, advising generals, lecturing politicians, and consulting for major industries, few sought to mimic the otherworldly, detached demeanor of the prewar days.1
It was not just a matter of self-image. Physicists were being enlisted as soldiers in the Cold War. People were urgently needed to combat Soviet domination in the arms race and the space race—highly trained people skilled in the arcana of the new physics. Enrollments in physics courses exploded. At the start of the World War the United States was turning out fewer than 200 physics PhDs per year—but by 1960 that number had more than tripled, and by 1970 it had passed 1,500. In such an atmosphere there was no need—and no time, and maybe even no stomach—to go into such charming stuff as the ultimate nature of reality. Tough people were wanted: can-do types who would roll up their sleeves, brush aside the niceties, and get down to cases. People with deadlines to meet and jobs to do.
And the world got what it wanted.
a. The error was discovered in 1935 by Grete Hermann—and then again independently by Bell himself many years later.
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