Big Science Page 2
Money was abundant, but it came with strings. As the size of the grants grew, the strings tautened. During the war, the patronage of the US government naturally had been aimed toward military research and development. But even after the surrenders of Germany and Japan in 1945, the government maintained its rank as the largest single donor to American scientific institutions, and its military goals continued to dictate the efforts of academic scientists, especially in physics. World War II was followed by the Korean War, and then by the endless period of existential tension known as the Cold War. The armed services, moreover, had now become yoked to a powerful partner: industry. In the postwar period, Big Science and the “military-industrial complex” that would so unnerve President Dwight Eisenhower grew up together. The deepening incursion of industry into the academic laboratory brought pressure on scientists to be mindful of the commercial possibilities of their work. Instead of performing basic research, physicists began “spending their time searching for ways to pursue patentable ideas for economic rather than scientific reasons,” observed the historian of science Peter Galison. As a pioneer of Big Science, Ernest Lawrence would confront these pressures sooner than most of his peers, but battles over patents—not merely what was patentable but who on a Big Science team should share in the spoils—would soon become common in academia. So too would those passions that government and industry shared: for secrecy, for regimentation, for big investments to yield even bigger returns.
It was Lawrence who had helped plant the seed of industry’s involvement in research by feeding the ambitions of his patrons with visions of how the cyclotron would serve their favored goals. For biological research institutions, he played up its capacity to produce large quantities of the artificial radioisotopes needed to comprehend the complexities of photosynthesis and to attack cancer cells. He plied industrialists with visions of the atomic nucleus as a generator of electricity that would be unimaginably cheap and almost infinitely abundant. As for those philanthropic foundations still devoted to basic research, he offered the prestige of association with projects aimed at unlocking the secrets of the natural world as its own reward. Raymond B. Fosdick, president of the Rockefeller Foundation, delivered perhaps the most concise distillation of this aspect of Big Science. “The new cyclotron is more than an instrument of research,” he stated in 1940. “It is a mighty symbol, a token of man’s hunger for knowledge, an emblem of the undiscourageable search for truth which is the noblest expression of the human spirit.” That year, the nonprofit foundation’s board had voted to grant Lawrence more than $1 million to build the most powerful cyclotron on earth.
There was nothing cynical about Lawrence’s appeals to the interests of his financial backers. His most assiduous fund-raising efforts would have come to naught had he not been able to back up his promises with a record of genuine achievement. Berkeley’s Radiation Laboratory pioneered the new science of nuclear medicine to fight disease. Its cyclotrons often ran overtime to produce radioisotopes for researchers all over the world. Lawrence’s conviction that energy from the atom might someday heat and illuminate millions of homes and factories and send seagoing vessels around the globe was visionary, but no less heartfelt for that—and, of course, it turned out to be true.
The successes of Big Science brought great public esteem to scientists, who became honored and admired as the men and women who had helped win the war and who served as living repositories of mankind’s impulse to learn nature’s secrets. That degree of lionization could never last, for science’s knowledge is imperfect and the public always primed for disillusionment. Scientists began to totter on their pedestals just as the projects of Big Science, growing ever bigger, threatened to consume an outsized share of the public resources needed to address more urgent social problems.
Toward the end of the twentieth century, Big Science’s grip on the confidence of society started to ebb. Many of its achievements seemed, in retrospect, equivocal: yes, the atomic bomb won the war, but at the price of a permanent nuclear cloud hovering over the human race. The peaceful atom brought electricity, but at a much higher price than had been forecasted by its promoters—and it also brought us the disasters at Three Mile Island, Chernobyl, and Fukushima, raising the question of whether the technology of nuclear power ever could be reliably tamed by mankind. Men walked on the moon, but after that spectacular moment, public interest in space exploration drained swiftly away. All that expense—for what?
In the same 1961 essay in which he coined the term Big Science, Alvin Weinberg outlined the emerging doubts about its impact on research, the university, and society. He asked, quite properly, if massive expenditures to erect monuments to Big Science would suck up scarce resources and distract scientists from inquiries more relevant to the human condition: “I suspect that most Americans would prefer to belong to the society which first gave the world a cure for cancer,” he wrote, “than to the society which put the first astronaut on Mars.”
In the United States, such doubts energized the debate in the 1980s and early 1990s over the Superconducting Super Collider, an accelerator to be located near Waxahachie, Texas, which would have been as much as three times as powerful as CERN’s Large Hadron Collider. The project eventually foundered on the shoals of regional and budget politics, but it had already been mortally wounded by public skepticism about its purpose. In 1993 the SSC was killed by Congress.
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The Large Hadron Collider is so vast, complex, and costly that some scientists wonder whether it might mark the end of Big Science on the international level. Its discoveries raise questions about the natural world that can be answered only by bigger, more powerful colliders, in the same way that each of Lawrence’s cyclotrons established the need for the next bigger one. Like the Large Hadron Collider, the next machine, if it is to be built, will require a consortium of nations. Getting them to collaborate on a quest that to the layman seems hopelessly abstract will not be easy.
Ernest Lawrence never expressed such misgivings. His goal was to address “the problem of studying nature,” as Robert Oppenheimer put it, and his career achieved that end. That it is left to us to deal with its implications does not diminish his achievement. But it does compel us to examine how it came about. The story begins with the towering figures of the small-science world.
Part One
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THE MACHINE
Chapter One
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A Heroic Time
Ernest Rutherford was one of science’s Great Men, a towering figure who drove developments in his era rather than riding in the wakes of others. To an acquaintance who observed, “You’re always at the crest of the wave,” he was said to have replied: “Well, after all, I made the wave, didn’t I?” He was loud, with a boisterous laugh and a hearty appreciation of what was known in his time as “smoking-room humor.” C. P. Snow, a youthful associate of Rutherford’s who would win literary fame with novels set in the corridors of academia and government, remembered Lord Rutherford as “a big, rather clumsy man, with a substantial bay window that started in the middle of the chest” and “large staring blue eyes and a damp and pendulous lower lip.”
Born in 1871 to a handyman and his wife in New Zealand when it was a remote outpost of the British Empire, Rutherford became an intuitive theorist and the preeminent experimental physicist of his age. No one could question his talent for divining the significance of the results produced by his elegant handmade equipment. “Rutherford was an artist,” commented his former student A. S. Russell. “All his experiments had style.”
Rutherford was twenty-four when he first came to Cambridge University’s storied Cavendish Laboratory on a graduate scholarship. It was 1895, a fortuitous moment when physicists were pondering a host of strange new physical forces manifested in their apparatuses. Only a month before Rutherford’s arrival, the German physicist Wilhelm Roentgen had reported that a certain electrical discharge generated radiation so penetrating it could produce an
image of the bones of a human hand on a photographic plate. Roentgen called his discovery X-rays.
Roentgen’s report prompted the Parisian physicist Henri Becquerel to look for other signs of X-rays. His technique was to expose a variety of chemical compounds to energizing sunlight. He would seal a photographic plate in black paper, cover the paper with a layer of the candidate compound, place the arrangement under the sun, and check back later to see if a shadow appeared on the sealed plate. During a stretch of overcast Paris weather in February 1896, he shut away in a drawer his latest preparation: a uranium salt sprinkled over the wrapped plate, awaiting the sun’s reemergence from behind the clouds. When he developed the plate, he discovered it had been spontaneously exposed by the uranium in the darkened drawer.
Marie Curie and her husband, Pierre, soon established in their own Paris laboratory that Becquerel’s rays were produced naturally by certain elements, including two that they had discovered and named polonium, in honor of Marie Curie’s native Poland, and radium. They called the phenomenon “radioactivity.” (Becquerel and the Curies would share the 1903 Nobel Prize for their work on what was originally called “Becquerel radiation.”)
Other scientists launched parallel inquiries to unravel the mysteries lurking within the atom’s interior. Cavendish director Joseph John “J. J.” Thomson, Ernest Rutherford’s mentor, discovered the electron in 1897, thereby establishing that atoms were divisible into even smaller particles—“corpuscles,” he called them. Thomson proposed a structural model for the atom in which his negatively charged electrons were suspended within an undifferentiated positively charged mass, like bits of fruit within a soft custard. Irresistibly, this became known as the “plum pudding” model. It would prevail for fourteen years, until Rutherford laid it to rest.
Rutherford, meanwhile, had busied himself examining “uranium radiation,” his term for the emanations discovered by Becquerel. In 1899 he determined that it comprised two distinct types of emissions, which he categorized by their penetrative power: alpha radiation was easily blocked by sheets of aluminum, tin, or brass; beta rays, the more potent, passed easily through copper, aluminum, other light metals, and glass. Rutherford had relocated to Montreal and a professorship at McGill University, which featured a lavishly equipped laboratory funded by a Canadian businessman, in an early example of scientific patronage by industry. Working with a gifted assistant named Frederick Soddy, who would coin the term isotope for structurally distinct but chemically identical forms of the same element, Rutherford determined that the radioactivity of heavy elements such as uranium, thorium, and radium was produced by decay, a natural transmutation that changed them by steps—in some cases, after minutes; in others, centuries, years, or millennia—into radioactively inert lead. Eventually alpha rays were identified as helium atoms stripped of their electrons—that is, helium nuclei—and beta rays as energetic electrons. The work earned Rutherford the 1908 Nobel Prize in chemistry. By then, he had already returned to Britain to take up a professorship at the University of Manchester.
There he would make an even greater mark on science by taking on the core question of atomic structure. “I was brought up to look at the atom as a nice hard fellow, red or grey in color, according to taste,” he remarked years later of the plum pudding model. But although he speculated that the atom was mostly empty space rather than a homogenous mass speckled with charged nuggets, he had not yet conceived an alternative model. With two Manchester graduate assistants, Hans Geiger and Ernest Marsden, he set about finding one, using alpha particles as his tools. As he knew, these were deflected somewhat by magnetic fields but, curiously, even more on their passage through solid matter—even through a thin film such as mica. This suggested that the atomic interior was an electromagnetic maelstrom buffeting the particle on his journey, not a serene, solid pudding.
Rutherford experimented by bombarding gold foils with alpha particles emanating from a glass vial of purified radium. Geiger and Marsden recorded the particles’ scattering by observing the flash, or scintillation, produced whenever one struck a glass plate coated with zinc sulfide. This apparatus displayed Rutherford’s hallmark simplicity and style, but the procedure was unspeakably onerous. The observer first had to sit in the unlighted laboratory for up to an hour to adjust his eyes to the dark, and then could observe only for a minute at a time because the strain of peering at the screen through a microscope tended to produce imagined scintillations mixed with the real ones. (Geiger eventually invented his namesake particle counter to relieve experimenters of the tedium.)
The experiment showed that most of the alpha particles passed through the foil with very slight deflection or none at all. But a tiny number—about one in eight thousand—bounced back at a sharp angle, some even ricocheting directly back at the source.
Rutherford was astonished by the results. “It was almost as incredible as if you fired a fifteen-inch shell at a piece of tissue paper, and it came back and hit you,” he would relate years later, creating one of the most cherished images in the history of nuclear physics. It was not hard for him to understand what had happened, for the phenomenon could be explained only if the atom was mostly empty space, with almost all of its mass concentrated within a single minuscule, charged kernel. The deflections occurred only when the alpha particle happened to strike this kernel directly or come close enough to be deflected by its electric charge. The kernel, Rutherford concluded, was the atomic nucleus.
Rutherford’s discovery revolutionized physicists’ model of the atom. But it was by no means his ultimate achievement. That came in 1919, he reported an even more startling phenomenon than the tissue-paper ricochets of 1911.
Rutherford had again relocated, this time to Cambridge, where he assumed the directorship of the Cavendish. The laboratory had opened in 1874 under the directorship of James Clerk Maxwell, who was a relative unknown at the time of his appointment; within a few short years, however, he had published the work on electricity and magnetism that made his worldwide reputation and established the Cavendish by association as one of Europe’s leading scientific centers. Maxwell’s conceptualization of electricity and magnetism as aspects of the same phenomenon, electromagnetism, would stand as the bridge between the classical physics of Sir Isaac Newton and the relativistic world of Albert Einstein, and his Cavendish would reign as the living repository of the British experimental tradition in physics.
In Rutherford’s time, the Cavendish reveled in its tatty grandeur, the epitome of small science in an institutional setting. The building was shaped like an L around a small courtyard: three stories on the long side, the top floor, with its gabled windows, crammed under a steeply raked roof. Inside the building were a single large laboratory and a smaller lab for the “professor,” a room for experimental equipment, and a lecture theater. There Rutherford held forth three times a week to an audience of about forty students, occasionally consulting a few loose pages of notes drawn from the inside pocket of his coat. Physicist Mark Oliphant, arriving at the Cavendish from Australia in the mid-1920s, remarked on its “uncarpeted floor boards, dingy varnished pine doors and stained plaster walls, indifferently lit by a skylight with dirty glass.” As for the director, he described Rutherford as “a large, rather florid man, with thinning fair hair and a large moustache, who reminded me forcibly of the keeper of the general store and post office.” The lab adhered strictly to the European “gentlemen’s tradition” of closing its doors for the night at six o’clock regardless of whether any experiments were in progress, with an elderly timekeeper assigned to glower at the lab bench of any scientist still working, rattling the lab keys to remind him of the time. Working late was considered “bad taste, bad form, bad science.”
The Cavendish treasured its history of having made great strides with scanty resources. Its entire annual budget was about £2,000, worth about $80,000 in twenty-first-century US currency and meager even in the old days for the magnitude of its work. What took up the slack was the shrewdness and cr
aft of Rutherford’s associates, their ability to extract the maximum results from experimental apparatus of marked simplicity and elegance. The 1919 experiments would exemplify the Rutherford style.
Working with James Chadwick, whose experimental skills matched his own, Rutherford trained his alpha particles on a series of gaseous targets: oxygen, carbon dioxide, even ordinary air. With their apparatus, a refinement of the Marsden-Geiger box of 1911, they found that ordinary air produced especially frequent scintillations resembling those of hydrogen nuclei, or protons. Rutherford surmised correctly that the phenomenon was related to the 80 percent concentration of nitrogen in the air.
“We must conclude,” he wrote, “that the nitrogen atom is disintegrated . . . in a close collision with a swift alpha particle, and that the hydrogen atom which is liberated formed a constituent part of the nitrogen nucleus.” These circumspect words produced a scientific earthquake, for what Rutherford described was the first artificial splitting of the atom. It would eventually be recognized that the reaction entailed the absorption of the alpha’s two protons and two neutrons by the nitrogen nucleus—seven protons and seven neutrons—followed by the ejection of a single proton, thereby transmuting nitrogen-14 into the isotope oxygen-17. But what really set the world of science on a new path was the vision that Rutherford set forth at the close of his paper. “The results as a whole,” he wrote, “suggest that if alpha particles—or similar projectiles—of still greater energy were available for experiment, we might expect to break down the nucleus structure of many of the lighter atoms.”