“Lawrence both made his reputation with some people and lost it with others at that meeting,” Livingston reflected later. Chadwick’s disdain was especially irksome: “For years afterward, Chadwick thought all the reports from Berkeley must be literally fabricated.” He was not assuaged by the more charitable opinion of his superior, Rutherford, who was delighted with Lawrence’s spirit in defending his results. Rutherford lectured Chadwick, “He is just like I was at his age.”
Rutherford cheerily tendered an invitation for Lawrence to visit the Cavendish, which Ernest accepted eagerly. During the visit, Chadwick continued to show his sulky side, treating the American so rudely that his colleagues and friends were forced to make excuses. “I gathered that you ‘ran up against’ Chadwick while in Europe,” commiserated Ernest Pollard of Yale, who had received his doctorate under Chadwick the year before. “I think what’s wrong with him is he is incredibly overworked. In the two years I worked with him, he seemed thoroughly tired the whole time—he and not Rutherford is the true director of Cavendish research.” Ernest acknowledged in reply, “He was a bit abrupt with me . . . Though I was a bit disappointed, I really don’t have anything against him because I respect his work so much.” Rutherford, however, compensated with his own blustery good will: “He’s a brash young man,” he told Oliphant after Lawrence departed, “but he’ll learn!” That made it all the more curious that it was Rutherford who would continue to resist the installation of a cyclotron in his distinguished old lab, and Chadwick, having moved on to the University of Liverpool, who would launch the first cyclotron construction project in Great Britain and become one of Lawrence’s closest professional friends.
But that was years in the future. For the moment, Chadwick’s scorn, sounding as it did from deep within the bastion of small science, rankled deeply. Back in Berkeley, Lawrence redoubled the pace of the deuton bombardments. He seemed driven by the urge to show Chadwick up. Bragging to one colleague about the magnitude of the bombardment program at Berkeley, he could not resist adding that “perhaps before long, the evidence will be such as to convince the most skeptical . . . even Chadwick.” Informed by Livingston, who was on sabbatical at Caltech, that Charles Christian “C. C.” Lauritsen, a Danish physicist recently appointed to the faculty there, was observing neutrons from deuton bombardments of aluminum, carbon, and copper, he replied, “It seems to me that Chadwick will have to come down off his high horse now.” He even poked a stick into the lion’s cage with a letter to one Cavendish scientist bragging that he had found “unambiguous proof” of deuton disintegration and adding, “It would seem now that even Chadwick would agree.” And in a paper for the Physical Review, he attempted to refute directly the Cavendish assertion that his results were caused by contamination: “A series of measurements with several sets of carefully cleaned targets showed the same phenomena.” For the Research Corporation, which was funding much of this work, Lawrence erected a lofty scientific beacon on a foundation that almost everyone but he thought shaky: “This first definite case of an atom that itself explodes when properly struck is of great interest, not only as a possible source of atomic energy, but especially because it is not understandable on contemporaneous theories . . . [It] promises to be a keystone for a new theoretical structure.”
Yet the tide was distinctly turning against Lawrence’s position. Rather than confirm Lawrence’s results, Caltech’s Lauritsen contradicted them, positing that the neutrons produced by his bombardments had come from disintegrating targets, not disintegrating deutons. His report, which appeared in the Physical Review next to another defense of the lightweight neutron from the Rad Lab, accepted Chadwick’s neutron weight as a given without even alluding to Lawrence’s theory, as though it were not worth any attention.
A worse blow was coming. Its source was Merle Tuve, whom Lawrence had visited in Washington on his way home from Europe. Lawrence had asked his childhood friend to double-check the Rad Lab’s results using the Carnegie’s accelerator, the only machine in the world that could approach the cyclotron’s energies. All that Tuve could confirm, however, was the shocking sloppiness of the Rad Lab’s work. “After working up all of our data,” he wrote in a “Dear Ernie” letter in February, “we reached the astounding conclusion that we were unable to check a single one of the observations which you have reported.” The inescapable explanation, he declared, was contamination. Put bluntly, Lawrence’s poorly focused beam was coating the cyclotron’s interior surfaces with deutons. Rather than a self-destructing deuton, which would be remarkable, Lawrence was detecting the effect of deuton-deuton fusion, which was also remarkable in its way—just not in the way Lawrence had defended so vehemently all these months.
The evidence from the Cavendish, the Carnegie Institute, and Caltech had to be judged irrefutable. On February 28 Cockcroft wrote to tell Lawrence that painstaking purification of the bombardment targets eliminated evidence of an exploding deuton entirely, providing “very good justification for [our] refusing to commit ourselves to your hypothesis.” The gentlemanly Oliphant followed up two weeks later with the observation that as little as a single layer of contaminating deutons would produce the erroneous results. (“Do you think this at all possible?” he asked charitably.) The ultimate explanation of Lawrence’s error came, perhaps inevitably, from Rutherford, who demonstrated once again the potency of his theoretical instincts when they were yoked to the experimental precision of the Cavendish. One night he jolted Oliphant awake with a three o’clock phone call to declare that the deuton-deuton collisions produced two reactions with almost equal frequency: one emitting a proton and creating a hydrogen isotope with two neutrons (that is, tritium), and another emitting a neutron and creating a helium isotope of atomic number 3.
A startled Oliphant asked him what reasons he could have for reaching such a conclusion. “Reasons! Reasons!” Rutherford roared back. “I feel it in my water!” Rutherford’s conclusion meant that Lawrence, in his myopic insistence on a dubious model, had missed the discovery of two new isotopes—which Rutherford, performing as a one-man old guard, had recognized in a characteristic flash of insight.
Lawrence now faced the task of climbing down from his discredited position without sacrificing his dignity or the Rad Lab’s youthful reputation. The process began gingerly, with a candid letter to the Physical Review signed by Lawrence, Lewis, Livingston, and Henderson conceding that “alternative and reasonable explanations have been found for those phenomena which originally led us to the hypothesis of the instability of the deuton.” They acknowledged that further studies would likely show that contamination “will ultimately account completely for our observations.”
This was an exceptionally frank confession, though no less so than was demanded by scientific convention. Lawrence followed it up with personal letters to Cockcroft and Tuve bearing almost identical words of contrition: “I can not understand my stupidity in not recognizing this possibility [that is, contamination] when the experiments were in progress . . . I regret very much that the question of deuton instability involved you in so much work and want to thank you very much for stepping in and clearing the matter up so effectively and so promptly.” His letter to Cockcroft crossed in the mail with one from Ralph Howard Fowler, Rutherford’s son-in-law and deputy at the Cavendish. Gracious to a fault, Fowler comforted Lawrence with the gratifying assertion, surely untrue, that “for a long time Rutherford and Chadwick were nearly convinced that your explanation was right.”
Tuve was not so forgiving. To Cockcroft he grumbled that Lawrence’s mistake was “one of judgment and point of view rather than of the errors in technique which can give rise to such a situation.” Perhaps he had become frustrated watching his boyhood chum collect accolades and public acclaim for his marvelous engineering while complacently performing atrocious physics. Even worse, Tuve felt, was that Lawrence’s disinclination to confirm his own results before publishing them had placed an intolerable burden on scientists at other labs, who had wasted time and m
oney trying to confirm unconfirmable results.
Tuve upbraided Lawrence personally in even a harsher tone. “In the face of the very general interest which has been aroused by your publication,” he wrote irritably, “we have decided that the only way to handle the situation was to make a bald statement of the extent to which we have endeavored to check your results and failed. There is no way of evading the question much longer . . . I must say that we here have certainly not enjoyed the position in which we have been placed. Once in a lifetime is once too often.” He then disclosed that he had already mailed his report to the Physical Review. Tuve’s indignation revived Lawrence’s defensiveness: “It would seem,” Ernest replied, “that you are overstating things a bit with the remark that you are unable to check a single one of our observations.”
The final act of this family drama played out at the annual meeting of the American Physical Society, held on Lawrence’s home turf in Berkeley in mid-June. Tuve presented his findings, as did Caltech’s Lauritsen, neither leaving any doubt about the divergence between his results and the host’s. “Intensive discussion” ensued, according to the official report of the meeting in Science, written by Ernest’s departmental colleague Leonard Loeb. Those mild words failed to do justice to the bitterness of the discussion, which included intemperate attempts by both sides to discredit each other; at one point, Raymond Birge, the easygoing Berkeley physics chairman, had to physically separate Lawrence and Tuve and calm their inflamed feelings. Loeb’s report attempted to paper over the differences in the experimental results, stating that the findings by Lawrence, Tuve, and Lauritsen “are not contradictory in the least, but rather supplementary” and assuring readers that the three papers “made a consistent picture.”
This incensed Tuve, who shot off a “correction” attacking Loeb’s report as “erroneous and misleading.” Lest anyone doubt where he placed the blame, he referred to the Rad Lab’s “abandonment several months ago of a striking hypothesis . . . which they were notified could not be substantiated in Pasadena, at Cambridge nor here in our laboratory.” The idea that the three labs’ results were “ ‘not contradictory’ . . . is an optimistic one for which I am not responsible, and to which I do not subscribe.”
• • •
The deuton affair was a turning point for the Rad Lab. All through the fall of 1933, Ernest Lawrence had been on a soaring high, his fame growing within the physics fraternity and among the public. The cyclotron’s celebrity as a technological phenomenon fed on itself, fueling its inventor’s preference for engineering and salesmanship over the tedious drudgery of hard science. The thousand-ton behemoth filling the old wooden shed on the Berkeley campus was a device that industrialists and foundation directors could appreciate; it was harder for them to apprehend the abstruse science that was its proper quarry. The failures of Ernest’s science seemed not to matter as long as his patrons were willing to write their checks, and researchers and laymen were so eager to be thrilled by the concept of multimillion-volt protons that they did not pause to ask what they were good for. But they mattered to scientists, who would be the ultimate judges of whether the money being spent on Big Science was spent wisely.
Even before the deuton affair, some Rad Lab researchers were questioning whether the cult of the machine had not overwhelmed the drive for basic science. They swallowed their complaints, sometimes because they too were swept up in the excitement of pushing the technical capabilities of the cyclotron further and further. At the Rad Lab, it seemed, one could get away with a half-finished research project, but shirking one’s nighttime shift operating the machine was a sin. The harvest of this upside-down approach to nuclear research now lay before them.
For those already skeptical of the cyclotron, Lawrence’s error reinforced their scorn. Among them was Rutherford. In the aftermath of the controversy, he told Chadwick, “I’m not going to have a cyclotron in the Cavendish.” Rutherford’s attitude arose not merely from the poor showing the machine’s results made at the Solvay in 1933 but from his personal approach to research. “Rutherford had a horror of complicated equipment,” James Chadwick would recall. Of course, he added, this was quite natural for a scientist who had achieved repeated triumphs with instruments scaled to fit on a laboratory bench.
But the complexity of nuclear physics was rapidly outstripping the capabilities of the laboratory apparatus of small science. Chadwick saw the light well before Rutherford. In 1935, chafing under his mentor’s dictatorship much as Stan Livingston chafed under Lawrence, he decamped for Liverpool University, a steep downscale move for such a star of the Cavendish’s firmament, but preferable to picking a fight with Ernest Rutherford over research technique. “I was not prepared to quarrel with him,” he explained. Small science had not quite emptied its quiver: it would produce a few more spectacular successes, again somewhat at the expense of the Rad Lab’s reputation. But Chadwick knew the moment had arrived when only the high energies produced by the cyclotron would serve physics.
Liverpool was a poor institution with an undistinguished physics faculty. Chadwick would transform the place. A few weeks after he arrived, he received word that he had been awarded the Nobel Prize for discovering the neutron. One of the first letters of congratulations came from Lawrence. Ernest disclosed that he had received a visit from Arthur P. M. Fleming, research director of the British industrial giant Metropolitan-Vickers, and persuaded him to put up the money for a Liverpool cyclotron. Chadwick’s enthusiastic reaction showed him to be at heart not the crusty malcontent Lawrence had met at the Solvay but a professional devoted to science, eager for any assistance that might propel his penurious university into a higher sphere. “You would be surprised to know what this laboratory has been running on in the last few years,” he told Lawrence—“less than some men spend on tobacco.”
Liverpool was soon the happy recipient of Lawrence’s blueprints and two English-born, Rad Lab–trained physicists, dispatched to help Chadwick build his machine. As part of the vanguard of European cyclotron construction, the university soon would rival the Cavendish as the hub of nuclear science in Britain. As a European cyclotron center, it would be joined by Frederic Joliot’s lab in Paris, Bohr’s in Copenhagen, and then, miraculously, by the Cavendish, which in 1936 found itself “wallowing in cash” from two windfalls. The first was £30,000 paid by the Soviet Union to purchase the Cavendish lab equipment of Peter Kapitza, a Soviet citizen who had been detained by the regime during a visit home in 1934 and was kept happy by its commitment to duplicate his British laboratory in Moscow. The second was a donation of £250,000 from the automobile magnate Lord Austin, which ended the Cavendish’s poverty-row ways for good. All these places were soon populated by Berkeley-trained cyclotroneers, carriers of the DNA of Big Science around the world.
The Rad Lab’s recovery from the deuton embarrassment was aided by Lawrence’s candid confession of error (at least once the evidence became irrefutable). Inside the lab, he was sheepish: “This was a mistake, and a serious one,” Livingston recalled. “He told us we had allowed our enthusiasm to carry us along too fast and that we should be much more careful in the future in analyzing our results before we published.” But he also declared that error was an inevitable, even indispensable, part of the scientific method. “I have gotten over feeling badly,” he told Cooksey. “We would be eternally miserable if our errors worried us too much, because as we push forward, we will make plenty more.” But he resolved to bring theorists and experimentalists into closer contact in the lab, the better to challenge or reinforce one another’s judgments. And soon his cadre of skilled cyclotroneers would be supplemented by an infusion of inspired research talent, as scientists like Edwin McMillan, Franz Kurie, and Luis Alvarez would assume the job of turning the cyclotron from an engineering prodigy into a source of genuine scientific achievement. The first opportunity to show what it could do was just around the corner. But there would be one more harsh lesson to show how inattention could trump even the most inspired engin
eering.
Chapter Seven
* * *
The Cyclotron Republic
As the daughter and son-in-law of Marie Curie, Irène and Frederic Joliot-Curie were members of physics royalty. But that had not saved them from treatment as severe as Lawrence received at the Solvay Conference. Their error, according to the unforgiving delegation from the Cavendish, was in proposing a neutron even heavier than Chadwick’s. The result of their bombardments of boron and other light elements by alpha rays, moreover, had led them to propose that the proton was composed of a neutron and a positive electron, or positron. This contradicted Chadwick’s picture of the neutron as a compound proton and electron, though it raised the same difficult question as his: how to fit an electron, no matter its charge, into the prevailing model of the atomic nucleus.
Lawrence came home battered and bruised from Solvay, and capitulated to the criticism; the Joliots went home to their modest Paris laboratory determined to validate their theory of the neutron, and earned the Nobel Prize in the effort. Their method involved bombarding aluminum foils with alpha rays produced by their usual rudimentary source, a hunk of the inexpensive but vigorous alpha emitter polonium. As they expected, the bombardments drove positrons from the target foils. When they ceased the bombardments, however, the emissions continued in the same pattern as one would expect from a naturally occurring radioactive isotope. But theirs was not a natural isotope, it was an unstable isotope of phosphorus created in their laboratory. As their report in the French journal Comptes Rendus made plain, they had discovered artificial radioactivity.
Big Science Page 13
