Brotherhood of the Bomb

by Gregg Herken

  The impact of Adler’s teachings upon Oppenheimer in later life was evident in the ironic comment of a Dutch physicist who had befriended Oppie at Leiden. “Robert, the reason you know so much about ethics,” he observed cheerily, “is that you have no character.”57

  Almost all who knew Oppenheimer at Berkeley agreed that one incident—Oppie’s date with Melba Phillips, his first graduate student—was emblematic of the riddle that was his personality. When Phillips had fallen asleep during a drive with Oppie up into the Berkeley hills, Oppenheimer had simply parked the car and left the girl stranded while he walked home. To Oppie’s defenders, the episode was an example of their professor’s endearing absent-mindedness. To his detractors, including many he had snubbed or humiliated on the Berkeley faculty, it was proof of his casual cruelty.58

  “I can only think that perhaps when they were such really good friends, maybe they’d never really understood each other yet,” noted one of the boys who came to know both Oppenheimer and Lawrence well.59

  * * *

  One difference between them had to do less with temperament than with the times. As an experimentalist rather than a theorist, Lawrence was aware that a serpent lived in the garden of high-energy physics. The advent of the 27-inch cyclotron had flushed it out of the grass.

  With the increasing scale of his machines came a corresponding rise in cost and a subsequent need to find practical applications. While an experimental apparatus on a laboratory bench provided its own justification, finding funds for an 80-ton behemoth that required constant attention and consumed an enormous amount of electrical power needed a firmer anchor on utility; even if, as Lawrence firmly believed, the ultimate benefit to humanity—knowledge—was real and indisputable. The depression had imposed further parsimony upon science.

  Lawrence’s stint as a teenage cookware salesman had shown his early talent for raising the funds necessary to do his work. The economy with which Lawrence ran the Rad Lab was likewise notorious among colleagues. Scientists were routinely reminded to pick solder off the floor and reuse it. Lawrence once fired a fellow physicist—a subsequent group leader at Los Alamos—for ruining a pair of pliers.60

  Lawrence’s kitchen-chair cyclotron had given him the necessary foot in the door: a $500 bequest from the National Research Council toward a bigger machine that would reach energies of interest to physics. The expense of each successive cyclotron had increased by almost an order of magnitude, as had the energies achieved. The 11-inch cost less than $1,000. The 27-inch was nearly ten times that amount. In order to pay for getting its huge magnet trucked across the Bay to Berkeley, Lawrence persuaded a scientist-entrepreneur and philanthropist, Frederick Cottrell, that the work going on at the Rad Lab might bear looking into.61

  But luck, timing, and serendipity also contributed importantly to Lawrence’s success. Cyclotrons would probably have remained a theoretical curiosity were it not for the nearly simultaneous progress of vacuum tube technology, itself the result of the phenomenal growth of commercial radio in the early 1930s. Lawrence’s introduction to science had come as an amateur radio buff in high school.62 Merle Tuve, another early experimenter with wireless—and Ernest’s boyhood friend on the prairie—later became a department head at Washington’s Carnegie Institution.

  In another happy coincidence, the oscillator vacuum tubes used in the cyclotron operated near the same part of the radio-frequency spectrum as x-ray tubes made for the diagnosis and treatment of disease. This overlap fortuitously pushed the boys early on into building machines for medical research.

  One of Lawrence’s graduate students, David Sloan, had already built a 1-million-volt x-ray tube three times more powerful than existing hospital equipment. Sloan’s invention interested Cottrell as well as Lawrence’s colleagues across the Bay, at the University of California’s medical school and hospital in San Francisco. By 1933, radiologists at University Hospital were using Sloan’s x-ray tube for the treatment of cancer patients.63 But Ernest hoped that the cyclotron itself might someday become a weapon in the physician’s armamentarium against disease. As he was quick to recognize, the ability of neutrons to penetrate tissue promised to make them useful in the treatment of cancer: a tightly focused cyclotron beam might conceivably destroy malignant tumors while leaving nearby healthy organs untouched. Cottrell’s support left Lawrence optimistic about invoking the muse of medicine to pay the bills for his cyclotroneers.

  Ironically, Ernest’s interest in the biological effects of radiation also stemmed from a concern with how the cyclotron might be affecting the health of the boys.64 He soon found that there was good reason to worry.

  Early in 1934, a husband-and-wife team of physicists in Paris, Frédéric and Irène Joliot-Curie, discovered the phenomenon of induced, or “artificial,” radioactivity. Two months later, in Italy, physicist Enrico Fermi proved that radioactivity could also be induced by neutrons, a feat that earned him the Nobel prize.65

  Both discoveries could and should have been made at the Rad Lab, since neutrons were something that the 27-inch at Berkeley was already producing in prodigious quantities. The tale would later be told that Lawrence had missed discovering artificial radioactivity because the cyclotron and the Rad Lab’s Geiger counter were both wired to the same switch—a tale that reflected upon Lawrence’s frugality as well as his impatience. But the truth was more damning, if less poetic.

  Two years after the Cavendish had stolen a march on the Rad Lab, Lawrence and the boys were still so preoccupied with where they might go that they had neglected to notice where they had been. The strong but variable background radiation that accompanied the operation of the 27-inch had long been attributed to an equipment problem. Evidently, no one had thought to look at a Geiger counter after the cyclotron stopped running.66 His laboratory’s headlong rush toward bigger machines, higher energies, and future funding had caused Ernest, once again, to ignore those more modest instruments that recorded the results of cyclotron experiments.

  Maddeningly, Lawrence and the boys were able to reproduce the Curies’ results within a half hour of reading about them in Nature. The steady clicking of the Geiger counter in the silent control room made it suddenly obvious to the cyclotroneers that they had been creating radiation artificially, and unknowingly, for more than a year.

  The Curies’ discovery brought changes both big and small to the Rad Lab. On the bright side, the 27-inch promised an unending supply of new radioisotopes, with different properties and as-yet-undreamed-of applications.67 But whereas it had once been common for tired experimenters to lean against the cyclotron when it was not operating, crude hand-lettered signs went up overnight warning against such behavior. Water-filled metal cans were hastily stacked around the machine to absorb stray neutrons. Whereas the boys had once only to fashion hats from newspaper to protect themselves against the machine’s best-known hazard—oil spraying from the vacuum pumps—they now had a more serious concern. “We realized we were wading through a sea of neutrons much more intense than existed anywhere else, and the lab itself was alive with radioactivity induced by cyclotron radiations,” one later wrote.68 Not only the coins in their pockets but even the silver and gold fillings in their teeth were made radioactive by the machine.

  Gruesome stories of carelessness around radiation were plentiful and well-known at the lab. All were aware of the tragic fate that had befallen the radium dial painters of the previous decade, who had inadvertently ingested the deadly element by licking the tips of their brushes to get a better point. The bones of the young girls had gradually grown brittle and melted away. Closer to home, the telltale black glove that covered the radiation-scarred hand of one of Ernest’s wedding guests still haunted Molly’s sleep.

  Nonetheless, a kind of disdaining bravado persisted among the cyclotroneers, many of whom viewed overexposure to radiation as a kind of occupational hazard. The attitude of one researcher at the Rad Lab—Joseph Hamilton, a physician from University Hospital—was not so much brave as reckless, or
even bizarre.*69

  Lawrence, tending toward the other extreme, declined even routine chest and dental x-rays. “I’m deathly afraid of cancer,” he once confided to a family member.70

  But Lawrence’s caution was sometimes overridden by enthusiasm, or thoughtlessness. Robert Stone, the chief radiologist at University Hospital, recalled how shivers had run down his spine when Ernest first showed him the poorly shielded Sloan x-ray tube in operation at Berkeley. Stone was further astonished to learn that Lawrence had forgotten to budget any funds for shielding the 1-million-volt tube when it was about to be installed in the hospital clinic.71

  For all that, the only radiation casualty thus far at the Rad Lab had been the tube’s inventor, Sloan—who damaged his spine carrying 200-pound pieces of lead battery plate, scrounged from the dump and belatedly seized upon by Lawrence as the answer to the shielding problem.72

  In summer 1935, Ernest enlisted the aid of John, his physician brother, then teaching at Yale, to deal with radiation concerns at the lab. An early experiment by John provided what seemed at the time a suitable cautionary tale: the boys were left silent and chastened when a laboratory rat placed in the target chamber of the 27-inch was found dead following a bombardment—until the gleeful cyclotroneers discovered that it was asphyxiation, not radiation, that killed the rat.

  His brother’s visit convinced Ernest that the future of the cyclotron, and perhaps of the Rad Lab, lay in medical research. Both the Macy and the Rockefeller foundations, searching for cancer cures, had meanwhile joined Cottrell’s Research Corporation as major backers of Lawrence’s laboratory. With showmanship worthy of Barnum, Ernest and John used graduate students, colleagues, and themselves to demonstrate how radiosodium coursed through the body, promising a faster and safer tracer than radium. Moments after volunteers drank a solution of the isotope in water, Ernest or John would follow its path with a clicking Geiger counter.73

  John eagerly returned to Berkeley the following year, driving cross-country from Yale with a car full of cancer-ridden mice to be used in cyclotron experiments.

  The spreading fame of Lawrence and his laboratory was making Berkeley a beacon that attracted physicists from around the world. In 1936, shortly after beating back an attempt by Harvard to lure Ernest east, Sproul agreed to make the Radiation Laboratory an autonomous part of Berkeley’s physics department, with Lawrence as its director.74 Birge, who paid the most for this concession, pronounced himself satisfied with the bargain. But even the physics chairman, who supposedly had jurisdiction over Ernest’s growing empire, admitted that he did not really know what went on at the Rad Lab. As Birge wearily remarked to a professor at another school, Berkeley had become less “a university with a cyclotron than a cyclotron with a university attached.”75

  A year later, the 27-inch was transformed into a 37-inch cyclotron; durable rubber gaskets replaced the ubiquitous red sealing wax. Cooksey’s prized yellow Packard Phaeton—“The Creamliner”—was used to anchor the hoist that brought the huge vacuum chamber into the lab.76 In September 1937, the machine reached a record 8 million electron volts. A few weeks later, Lawrence appeared on the cover of Time magazine after winning the National Academy of Sciences’ prestigious Comstock award. Lawrence used the prize money to buy a cabin cruiser for impromptu overnight trips up the Sacramento River. Although the vessel slept four, Lawrence routinely invited ten of the boys. Molly claimed her husband kept navigation charts onboard just to identify the sandbars they became stuck on.77

  * * *

  By late that year, the new cyclotron was being run around the clock to meet the demand for medical radioisotopes, which Ernest and John distributed without charge to hospitals and research laboratories around the world. Tiring of the commute from New Haven, John had finally decided to join his brother permanently on the West Coast.78 He, Stone, and Hamilton had been the first physicians to put cyclotron-produced radioisotopes to medical use.

  Experiments by physics graduate students were suspended for one day a week so that cancer patients could be treated with neutrons from the cyclotron. White hospital screens temporarily hid the oil-covered machinery and the boys grudgingly agreed to don hospital gowns for the day. Cyclotroneers who complained that the medical research tail had begun to wag the physics dog were not-so-gently reminded by Ernest which end it was that brought in the necessary grants.79

  The Lawrence brothers put their faith in the new medical technology to the test at the end of 1937, when Gunda was diagnosed with incurable uterine cancer. Doctors at the Mayo Clinic had given the sixty-five-year-old woman only months to live. Once a week, John accompanied Gunda on the ferry across the Bay to Stone’s clinic, where she received several times the usual radiation dose from Sloan’s x-ray tube. The treatments were both painful and debilitating; Gunda often vomited out the car window from radiation sickness on the drive back from the hospital. But the tumor gradually shrank. By that spring, John predicted the eventual full recovery.80

  * * *

  The boys had meanwhile been joined by new recruits, drawn to Berkeley like a flame by Ernest’s self-proclaimed “paradise of physics.” Already a veteran was Edwin McMillan, a shy, soft-spoken physicist who had arrived from Princeton in the winter of 1932. An experimentalist like Lawrence, the two men shared another, more personal bond: Ed was dating and would soon marry Molly’s younger sister, Elsie.

  Luis Alvarez was still a student at the University of Chicago when he met Lawrence at the Century of Progress Exposition. Despite his Spanish surname, “Luie” was the grandson of Irish-born missionaries and looked Scandinavian. Brilliant, arrogant, and ambitious, Alvarez was recruited to Berkeley by Birge in 1936 but soon concluded that Ernest and the Rad Lab offered more of a career open to talent.81 While Lawrence would later speak admiringly of “the Alvarez style—something out of the ordinary,” for the interim his new star was obliged to share quarters with John’s laboratory animals in a smelly building known on campus as the “Rat House.”82

  The most recent new arrival at the Rad Lab was an émigré from fascist Italy. A small, outspoken, and volatile man, Emilio Segrè was a former student of Fermi’s. Segrè had been teaching at the University of Palermo when he received a letter from Lawrence that contained a piece of the 37-inch’s deflector. From that radioactive metal fragment, Segrè and a colleague had isolated the first man-made element, which they dubbed “technetium.”83 Segrè was visiting Berkeley in 1938 when he learned that Mussolini’s anti-Jewish decrees made it impossible for him to return to Italy.84

  Although Lawrence would later claim to have rescued Segrè from the fascists, some at the Rad Lab—Segrè included—felt that Ernest actually took advantage of the Italian’s plight, paying him barely more than a graduate assistant. Behind Ernest’s back, the touchy Italian returned the affront—spreading the story that John Lawrence had never really recovered from a blow to the head received in a near-fatal car accident. Segrè also found Oppenheimer’s continental pretensions “slightly ridiculous.”85 While resolved to be a good citizen of what he called “the Cyclotron Republic,” Segrè nonetheless discreetly sounded Birge out about finding a permanent job in the physics department.86

  Martin Kamen, a slight and somewhat disheveled-looking chemist from Chicago, was put to work making radiophosphorus for John’s medical experiments. The late-night antics and bohemian lifestyle of the twenty-three-year-old Kamen drew pursed lips and disapproving looks from Lawrence but favor from the boys. (In one celebrated contest, initiated by Kamen, inebriated cyclotroneers vied to see who could do the greatest number of pull-ups on the suspension cables of the new Golden Gate Bridge; Kamen won.)87

  Years later, Kamen would learn about the price of empire the hard way, when he and a colleague in the chemistry department, Sam Ruben, used Lawrence’s cyclotron to synthesize the first long-lasting radioisotope of carbon. Like radiosodium, carbon-14 held promise as a biological tracer. When Kamen went to Ernest’s home one rainy night to announce the discovery, Lawrence, suffering
from a bad head cold, sprang from his sickbed to embrace the young man.

  But Lawrence’s joy turned to “ill-concealed anger” just days later, Kamen recalled, when the scientific paper announcing the discovery gave Ruben and the chemistry department precedence over the Rad Lab.88 Lawrence had turned on his heel and wordlessly walked away when Kamen offered him the paper. To the young chemist, the incident showed that not even Ernest was immune to chauvinistic pride, and that there was a dark side to Lawrence’s ambition.

  * * *

  Even before the 37-inch cyclotron had reached its theoretical limits, Ernest was looking for new worlds to conquer. Indeed, he already had a bigger machine in mind. At Chicago’s Century of Progress Exposition, he had talked about a future “atomic gun which in comparison with the present one will be like a 16-inch rifle alongside a mere one-pounder.”89 At the time there had been no interest in building such a machine, but that changed with the discovery of artificial radioactivity less than a year later.

  The next cyclotron would be specifically designed to produce radioisotopes and treat cancer patients. Since it was no longer as a supplicant physicist but as a freshly minted hero of medicine that Lawrence made his appeal, this time he planned to custom build the machine rather than assemble it from scrounged parts. Ernest asked Alvarez to calculate the optimum size of the magnet and McMillan to build the power supply. Edward Lofgren, a young grad student from southern California, was assigned to help McMillan and William Brobeck, the Rad Lab’s only engineer.90

  Lawrence had decided that his “medical cyclotron” should operate in the neighborhood of 20 million electron volts—an energy which, not coincidentally, was also of interest to physics. The pole faces of the new cyclotron would be 60 inches across; its magnet weighed 200 tons. A wealthy University of California regent, William Crocker, offered $75,000 toward construction of a new building on campus to house the machine.91