True Genius: The Life and Science of John Bardeen: The Only Winner of Two Nobel Prizes in Physics (2002)

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6 Academic Life J ohn shocked his Harvard colleagues when he brought Jane to the Fellows Society picnic in May 1938, and the more so when he mumbled that he guessed he would take his wife to Minne- sota. Few of his colleagues were even aware that he had a serious love interest. Miss Waldo at Dana Hall excused Jane from two classes so that she could attend the Fellows Society picnic. “Isn’t that sporting of her?” Jane wrote home. “She highly approves of my plans and was so amused when I broke the news.” Even Miss Helen Cooke, the schoolmistress “gave her blessing” but “was less enthusiastic.” Jane had enjoyed teaching biology to bright young women and was pleased to learn some months later from a friend that “all of her Dana Hall children had passed their college boards with ‘good,’ ‘honor,’ or ‘high honor.’” Even those who had tried her patience had done well. “It made me feel good that my struggles with them had turned out successfully.” Miss Cooke and Miss Waldo “were very complimentary about my success this year and said they wished, for Dana’s sake, that I were staying.” John’s new willingness to commit to Jane stemmed from his successful negotiations with the University of Minnesota. He had been offered a teaching position there starting in the fall of 1938. The land grant college in Minneapolis was modernizing its instruc- tional program. Physics was a targeted area. John Tate, dean of the 83 

84 TRUE GENIUS College of Liberal Arts and Sciences, managing editor of the Physical Review, and director of Walter Brattain’s Ph.D. thesis, had recently put Minnesota “on the map” of nuclear physics by adding J. Will- iam Buchta, John H. Williams, and Alfred O. C. Nier to its physics faculty. He hoped to do the same for solid-state physics. Now a full professor at Harvard, John Van Vleck again wrote a letter of recommendation on Bardeen’s behalf. Van Vleck had special connections with Minnesota, having taught there from 1926 to 1928. He sent Buchta a copy of the letter he had written to Johns Hopkins about several young physicists. Of Bardeen he wrote that Harvard thought “so highly of his work that we would like very much to keep him here but the financial situation is such that this is probably not possible.” Late in March, Minnesota offered Bardeen an assistant professor- ship. The salary, $2,600 a year, was less than he had made at Gulf five years earlier, but Bardeen knew he was lucky to have any offer at all. The academic pay scale could not be compared with the industrial one. Most universities had no theoretical physicists on their faculty. He accepted the offer. Minnesota also offered a position to Alfred Nier, who had over- lapped with Bardeen at Harvard from 1936 to 1938. Nier recalled Bardeen being irked when he found out that Nier had started at Minnesota with a higher salary than he. The reason was that Nier was well known at Minnesota, having done his graduate work there. When two physics posts opened for the fall of 1938, one was immediately extended to Nier. And when Harvard offered Nier another year of support, Minnesota countered with an offer a little higher than the usual starting salary. Wedding plans now took center stage for John and Jane. They agreed to keep expenses down by scheduling the event directly after one of John’s professional engagements. In July he had agreed to lecture on the physics of metals at a summer school hosted by the University of Pittsburgh. It made sense to have the wedding in Washington, Pennsylvania, where Jane’s family lived. “The date will probably be the 18th,” Jane wrote her mother late in May, “unless John can make it by the 16th. That is the day his lectures are over.” They planned a driving vacation for their honeymoon. Jane wrote her sister, “Johnny called tonight to say that he has just bought a new car, a 1937 Ford sedan.” 

Academic Life 85 A crucial issue was where to hold the ceremony. “My mother would be pleased,” Jane began, “if we had this wedding in a church.” John replied, “You can be married in the church if you want to, but not to me.” Choking back a laugh, she recognized that negotiation on this point would be fruitless. By getting married in the parlor of Jane’s family home, John and Jane were following a tradition set by Jane’s parents when they were wed in 1906. J. R. and Bess Maxwell then settled in Washington, Pennsylvania. Jane was born a year later, followed by two more girls, Betty and Sue, and two boys, Jim and Sam. Dr. Maxwell saw patients in his downstairs office at home for fourteen years. When he moved his practice to the McGugin Building, plenty of space became available at home for celebrations, such as Jane’s wedding. To please his new mother-in-law, John conceded to having the Rev- erend Dr. Lippencott, the father of Jane’s friend Mary Margaret Reline, perform the service. Only a few friends and family witnessed the wedding on Mon- day, July 18, 1938. It was a drizzly Appalachian summer morning. Most of John’s immediate family found a way to be there. Ruth and Ann drove from Madison, Tom and Janet from Pittsburgh. Several of John’s paternal relatives came from Syracuse, New York. All of Jane’s immediate family attended the ceremony. Mary Margaret and Bruce Reline were there to celebrate the long-awaited outcome of their matchmaking. Rejecting the “traditional white and veil,” Jane wore a simple white dress with a fringed jacket. John’s teenaged sister Ann admired the way the fringes shimmied when Jane moved. Jane’s aunt Margaret took the only snapshots of the event. After the ceremony in the parlor, everyone gathered in the dining and family rooms, where tables had been set for lunch. Then Jane ran upstairs to change into traveling clothes. As the couple drove off in their new Ford, John cringed at the clattering of the tin cans that Jane’s younger brothers had tied to their car. “That didn’t please John a bit,” Jane recalled. He removed them as soon as they were out of sight. Then the new Mr. and Mrs. Bardeen headed northwest to Madison so that John could show his boyhood home to his bride. “We drove as far as Canton, Ohio, the first night and picked out the best hotel in town.” As they drove out the next morning, “who should drive up along side us but Ruth, Ann, and their two friends,” 

86 TRUE GENIUS Jane wrote. “We stopped for a chat and complained about the lack of privacy on our honeymoon!” Jane was getting a feel for John’s family. She was happy to be part of it. Next they had “some lousy luck with a tire,” a blowout and no proper tools to fix it. Jane wrote home, “We borrowed a jack from a farmhouse and then had a hard time to get it under the car.” Jane began to suspect that she would become the family’s “fixer.” In later years, John’s frustration with mechanical things often brought outbursts of anger, not at people but at the tools that failed him. “John was pretty angry, as you can imagine,” Jane reported. “Finally we had to flag down another Ford in order to get a wheel wrench.” Eventually they reached a town “where we bought a tire and had the spare repaired. Then we shopped every Ford agency we came to trying to buy the missing tools.” They finally reached Madison about 4:30 P.M. on Wednesday— just an hour and a half ahead of Ruth and Ann, who had also spent the night in Warsaw a few blocks from John and Jane’s hotel. The next day John took Jane for a swim in the lake. They unpacked the Ford and “stowed the stuff away in Ruth’s cellar and attic.” Ruth offered them their selection of family photos. Jane found some “adorable baby pictures of John.” Ruth was having trouble getting household chores done with- out a maid, so the younger generation “pitched in and helped with the work.” With no time to send out their laundry, Jane did it her- self with Ruth’s help “and took a lot of kidding about washing and darning on my honeymoon. John was secretly much impressed and so proud of me that I didn’t mind the work.” On Saturday night John drove Jane around the Wisconsin cam- pus, and they went out for a beer at a student hangout with John’s brother Tom and his wife Janet, who had arrived from Pittsburgh earlier that day with their daughter Judy. Sunday morning the newlyweds drove to Green Bay to visit John’s brother “Willie” and his wife Charlotte. “They killed the fatted calf for us and showed us the town.” With no trace of resent- ment at spending her honeymoon on family rounds, Jane’s letters reflect only the pleasure with which she discovered that John valued family as much as she did. It was John who insisted that Jane write frequently to her own family, as promised. “He even threatened to write this letter himself.” After Green Bay they drove to Minneapolis, their new home. 

Academic Life 87 “All the people we have come into contact with here are very pleas- ant,” Jane wrote. “I think we are going to enjoy living here.” Ann Hustrulid, “another bride in the department,” helped them look for an apartment. The market was tight, but they found a small, reasonably priced flat at 701 Seventh Street S.E., a short walk from the university. They arranged for it to be ready by the time they returned from their honeymoon. From their spacious room at the Curtis Hotel, Jane wrote after eight days of marriage that she had “found more happiness being with John than my most rosy dreams led me to expect. Every day I discover new and lovable things about him and feel that I am a lucky girl to be his wife.” Heading west Jane marveled at the spectacular views in Yellowstone Park. In Montana they visited one of John’s geologist friends from Gulf. At Glacier National Park they hiked fourteen miles and made a pact to return for a longer vacation. At Lake Louise they again hiked fourteen miles. To save money, they made their own breakfasts. Jane wrote to her mother that John made “very good coffee, believe it or not.” Occasionally they rested, with Jane writing thank-you notes and John working on a physics paper. But John resisted making too many stops. When Jane asked if they could get out of the car to have a better look at a hill covered with wildflowers, he replied, “Can’t you see them from the car?” John was anxious to get to Vancouver and see his sister Helen, who was in a hospital there. She had contracted tuberculosis in nursing school at Yale, where she had met and married Donald Beach, then a medical student. Helen and Donald had been living with their young daughter Glenis, now age two, in Langley Prairie, British Columbia, until Helen became too ill to stay at home. The Bardeens visited with the Beaches for a few days. John fished with Don; the new sisters-in-law got along “famously.” But Jane intentionally made herself “scarce,” sensing that John and Helen needed time to “be free to talk about anything they wanted.” Helen, who could no longer work, asked John to help get her affairs in order, so that in the event of her death Glenis would be cared for. It had been almost a year since Helen had been near Glenis, who had not been allowed to see her mother in the hospital. It was therefore a special treat for Glenis and Helen when John, Jane, and Don took them for a two-hour drive in the car. “It is a desperate 

88 TRUE GENIUS fight for her,” Jane wrote of Helen, “but it is encouraging to know that people do recover from T.B. May she be one of those!” After saying good-bye to Helen and Don, the Bardeens headed down the West Coast to San Francisco and Yosemite National Park. They walked “about four or five miles through downtown Frisco and along the water front” and had “great fun” on the trolley cars. Jane wrote to her family about the splendor of the redwood forests and their stay at a “charming place on the edge of a grove.” She and John had become “pretty fair hikers by now, although I have a ten- dency to lag behind on upgrades. John sometimes has to give me a tow.” She apologized for writing fewer letters than usual. “We go so hard all day and John wants me to be with him all the time so that when night comes I haven’t time or energy left for writing.” The newlyweds made one last stop in Madison before heading to their new home in Minneapolis. They had driven more than 8,000 miles and had visited twenty-four states and two Canadian provinces. In Madison, John and Jane “rooted in the cellar” and found some “Chinese dishes which belonged to John’s mother.” They took them and the family photographs along with them. They carefully packed the dishes, photos, and wedding gifts into the car for the trip to Minnesota. Several wedding gifts caught up with them in Madison, including an elegant lace dinner cloth from Eugene Wigner. They stayed an extra day in Madison when they learned to John’s delight that Wigner was in town. Their apartment was ready when they returned to Minneapolis on September 7, 1938. Unfortunately the few household goods they had shipped from Pittsburgh had not yet arrived. Cashing a check for several hundred dollars, a wedding gift from Jane’s father, they bought a few furnishings, including the walnut bedroom set they would use for the rest of their lives. For another twenty dollars they bought six chairs and a secondhand dining table on which John did “a swell job of sanding and staining.” John’s dark red drapes from Lowell House, which had been altered to fit the new windows, “went fine” with Jane’s rug. Grateful that they didn’t have to “go into John’s capital,” they had, with the help of wedding gifts, “paid cash for everything.” Soon they realized they would also need a crib. Both were eager to start a family, but it was a surprise when Jane became pregnant 

Academic Life 89 during their honeymoon. John was thirty, Jane thirty-one. Jane had already “suspected something” by the time they got back from their trip, as she had begun to be plagued with morning sickness. “John, like a dear, brings me tea with sugar before I get up, gets his own breakfast, and thus permits me to take my time about getting started in the morning.” Mindful of appearances, Jane instructed her doctor, “Don’t let this baby come before spring.” “People are bound to count on their fingers,” she confided to her sister, “since the baby will arrive well in advance of our wedding anniversary.” By December, feeling the pinch of her expanding belly, she bought a few items of maternity clothing. A month later John teased that she “was going to produce a litter.” Her doctor disagreed, “being more used than my fond hus- band to the disastrous effects of pregnancy on the figure.” Jane was deeply touched when her new Minnesota friends threw a surprise baby shower for her in late February. “The most amazing present,” handmade by the husbands of two of her friends, was “a large wooden drawer in which to keep baby clothes.” Jane explained to her mother that it was “an exact replica of the book ‘Tiny Garments’ which Betty sent me.” Her friends had it “painted blue except for the sides which are natural color wood with the grain suggesting the pages. The drawer front is curved to resemble the back of the book and on the top Lynn had copied in black the title of the book and the picture of the baby that decorated the front cover of the real book.” Before leaving Dana Hall, Jane had asked Miss Cooke for a letter of recommendation, should she want to seek another teaching position. Having a child ruled that possibility out for her. Like most women of her generation, Jane considered a career incompatible with raising a family. When a former professor from the University of Pittsburgh urged her to continue her genetics studies at Minne- sota, she quipped that she was working on “a genetics project of my own.” Following in the footsteps of Althea and her own mother, Jane soon assumed all the household and family responsibilities, abandoning her own teaching and research so that her husband could concentrate on his. The Bardeens entered Minnesota’s academic circle easily. Jane often hosted parties at home. “I’m really enjoying cooking and don’t mind spending a lot of time on it,” she wrote to her mother, “but I certainly don’t get much satisfaction out of cleaning.” 

90 TRUE GENIUS John continued to have trouble making small talk. Writing to her mother about a new couple they had met, Jane expressed her hope that “we’ll continue to know them better because John really opened up and talked, which is unusual for him especially with people he doesn’t know well.” She began to assume the role that had earlier been played by John’s brother Bill, and later by Dutch Osterhoudt, of smoothing over some of the awkward gaps in John’s conversations. Jane had many friends among the wives of John’s colleagues. The closest were Vera Williams, Ann Hustrulid, and Florence Rumbaugh. The Rumbaughs and the Bardeens were a frequent four- some, sharing companionship, humor, and support. Florence and Jane commiserated when both their husbands contracted the flu, “exchanging ideas by telephone on care and behavior of sick hus- bands.” Jane reported, “John hates to take medicine, but he will stay in bed, which is something.” Again, John cultivated friendships through sports and other games. Both the Bardeens enjoyed bridge, then popular among aca- demic couples. John played billiards and golf with other physicists, sometimes during lunch breaks. One year he won the faculty billiards championship. John would usually play softball when someone worked up a game. At the physics department’s spring picnic, faculty and gradu- ate students traditionally faced off against one another. Nier bragged that with Bardeen, Williams, and Rumbaugh on the team, the faculty always won, which “ruined” the event. On one occa- sion the game broke off after a faculty-to-student score of “25 to 3 or something like that, and we chose sides to make it more fun.” The annual Physics against Chemistry game fared no better. In the late 1930s, physics chair Jay Buchta revived an earlier tradition of a friendly softball game between the two departments at their annual joint picnic. He tossed the gauntlet with an insulting note signed by everyone on the physics faculty. Chemistry accepted with an equally insulting letter sealed in a glass tube of pungent hydro- gen sulfide. Only one member of the chemistry faculty, however, was skilled enough to make its softball team. Physics was short on skillful graduate student players. In the end, the physics faculty ended up playing against the chemistry graduate students. “We beat them, of course,” Nier recalled smugly more than fifty years later. 

Academic Life 91 Bardeen was soon recognized as one of the department’s star athletes. Opponents who might have been lulled into complacency by his average build and mild manner did not take long to notice the superb control with which he wielded the tools of any game that he played. The control extended to his tongue. Not only could he refrain from saying anything until he knew precisely what he wanted to say, but he could also stop and start abruptly as circum- stances dictated. Nier claimed that Bardeen could be quietly grum- bling on the golf course after a bad shot, and immediately stifle his tirade when another golfer stepped up. Bardeen would then resume complaining where he had left off when the other’s shot was completed. Teaching a full program was a new experience for Bardeen, one that at first absorbed most of his time. He taught both under- graduate and graduate courses, initially finding both a bit intimi- dating. He had previously taught only his small Harvard seminar on relativity. “Since you’re the teacher,” he said to Jane, “tell me what I ought to be doing.” She suggested, “Tell them what you know.” He learned that like his father he was far better teaching one on one than lecturing to a group. He worked with several gradu- ate students but was not at Minnesota long enough to help them complete their doctorates. At the end of his first academic year at Minnesota, Bardeen felt lucky “to have the opportunity to teach during the summer and get a little extra money on the side.” But the heavy teaching load, espe- cially for the beginning physics course, drained him. “John had a hard week,” Jane wrote her mother in August. “The sudden plunge into teaching got him so on edge he couldn’t sleep.” Worried that he was wearing himself out, Jane planned a family drive to Madison. “John certainly needs to get clear away from Physics and teaching for a while. This summer school work is very exhaust- ing.” To sooth his nerves, she indulged his sweet tooth with “a batch of blackberry jam.” Jane soon learned that “vacations are for concentrating on research.” They were “about the only time he can get caught up with papers which have to be written,” she explained to her sister Sue. Money continued to be tight, especially when both John and Jane needed expensive dental work in the fall of 1938—just when they were setting up their household and saving for the baby. 

92 TRUE GENIUS John’s first project at Minnesota was to write up the paper he had delivered in Pittsburgh before the wedding. He began with an over- view of outstanding problems in the physics of metals before quan- tum mechanics. “These difficulties have been almost completely removed by modern quantum theory as applied to the problem by Sommerfeld, Houston, Bloch, Mott, and others.” Laying out the experimental picture concerning electrical conductivity he wrote, “Perhaps the most important thing an adequate theory of conduc- tivity must explain is the remarkable difference in conductivity between metals and insulators.” The early theories by Paul Drude and Hendrik Antoon Lorentz, he wrote, “did not attempt to give an explanation of these facts in any detail; they merely attempted to give the mechanism of conductivity.” Bardeen’s paper discussed Arnold Sommerfeld’s semiclassical theory of conductivity, mentioning William Houston’s estimate of the electrons’ mean free path, computed on the basis of Sommerfeld’s theory. He also described Felix Bloch’s theory and its remarkable consequence that “a perfect periodic lattice will have no resis- tance.” Outlining the difference between metals and insulators according to the band theory, he explained why “the ‘hole’ in the otherwise filled band acts like a particle of positive charge and posi- tive mass in the region of negative curvature, and like a particle of positive charge and negative mass in the region of positive curva- ture near the bottom of the band.” Moving into a more detailed discussion of conductivity and resistance, he appealed to works by his mentors Peter Debye and Percy Bridgman. Finally, he reported on problems of current inter- est in the field, such as the resistance of ferromagnetic metals and the conductivity of alloys. Disclaiming any attempt at complete- ness, he pointed out “some phenomena for which the Bloch theory has not yet provided even a qualitative understanding.” On his list were superconductivity and the curious observation by W. J. de Haas and his colleagues in Leiden of a minimum in the experimen- tal plot of electrical resistance versus temperature for gold at liquid helium temperatures. With great insight he pointed out, “It may be necessary in some cases to go beyond the Bloch picture to explain things which depend to a large extent on electron interaction, or on the cooperative action of a large number of electrons.” His conclu- sion summarized his own planned program of research in many- body theory, which he launched into after sending off the article. 

Academic Life 93 “Any labor pains yet?” was “John’s first question when he wakens and when he comes home in the evenings,” Jane wrote on May 4, 1939. It’s “going to be a big, fat girl,” he had teased her throughout the spring. “But of course he really wants it to be a boy.” Jane assured her mother they would telegram immediately when the baby came, “unless Johnny gets too excited over becoming a parent.” She made backup plans, asking a friend to call her mother if John forgot. While waiting, John painted furniture. He “is doing a fine job on the baby’s basket, but the bassinette still requires some fixing—John will probably be doing that the night before I return from the hospital!” James Maxwell Bardeen, named after Jane’s brother, arrived on May 9, 1939—four days late according to the doctor, but a little early according to Jane’s own calculations. Both John and Jane delighted in Jimmy. They were playful parents. “He was so much fun last night,” Jane wrote when Jimmy was six months old. “He was lying on his tummy on the couch with his head and shoulders raised up, supported by his arms. He started swaying from side to side and rolling his head. I imitated him and then he would repeat. He taught John the same trick. John calls it ‘playing bear.’” A year and a half later, when Jimmy could string words together, John set out to teach him about Newton’s laws. The little boy’s babble about bodies persisting in their state of motion was a hit at department gatherings. John’s enjoyment of children extended beyond his own family. He frequently ended up playing with the youngsters at social gatherings. Even after Jimmy’s birth Jane and John continued to enjoy a newlywed relationship. For Jane’s thirty-third birthday, “Johnny and I went gallivanting,” she wrote her mother. They had “dinner downtown,” then saw a show of Pinnochio “in celebration of the day.” Some months earlier she had baked a Valentine cake for John “decorated with small red cinnamon candy hearts.” When Jimmy was seven months old, Jane wrote to her family, “The kind of love that grows as you live with and really learn to know a man is so much more satisfying than the romantic fluff girls dream about.” John’s unusual reserve and his intense focus on physics none- theless created a gap in their relationship, one that was often pain- ful to Jane. Her feelings of isolation from John’s most ardent passions, especially physics and later golf, did not dissolve as the marriage matured. In Minnesota, she briefly tried to play golf in an 

94 TRUE GENIUS effort to be closer to John, but she soon gave it up in favor of attend- ing to home and family. Physics would remain John’s “first love” throughout their marriage. But in his ventures off into new scien- tific territory, Jane would serve as his anchor, as his family always had. By the summer of 1940 it was clear the Bardeens needed more space. Jane wanted a yard for Jimmy. They rented a small, three- bedroom frame house at 171 Arthur Avenue South East. “The house is not large but we are very comfortable,” she wrote to her mother in August. An open living and dining area and a small eat-in kitchen comprised most of the first floor. “The closets are wonderful— almost big enough to be rooms!” They treated themselves to a few conveniences. “John went downtown and bought me a swell Thor washing machine.” And “you knew about our new Frigidaire.” They had intended to buy rather than rent their next house, but the looming possibility that the United States would enter the war against Germany made them hesitate. “We’ve decided that we had better wait and see what happens before we sink all our capital into real estate and go into debt besides,” Jane wrote to her mother. “If Germany wins, as she may well do, there will undoubtedly be economic upheavals in this country.” Although short of money, the family made do. “Both of us feel that living within the income is more important than being lavish with our gifts,” Jane wrote home at Christmastime in 1939. Jane was willing to “try to be economical” so that they could send John to his physics conferences at the family’s expense. The American Physical Society meeting “really is an important occa- sion since it provides useful contacts and keeps him and his talents in the public eye.” When John flew to Washington in March 1940, Jane said he was “as excited as a small boy would have been” to be on his first airplane. He reported back to Jane, then shivering in the below-zero temperatures of a lingering Minneapolis winter, that the weather had been “perfect all the way.” The Bardeens starting combining family vacations with John’s professional trips. In late spring of 1940, he drove to Pittsburgh to attend a meeting of the American Physical Society, while Jane and Jimmy traveled ahead by train to visit with family in Washington, Pennsylvania. They accompanied John on the long drive back to Minneapolis. If Bardeen could not attend a meeting, a colleague would some- 

Academic Life 95 times present his paper, as Nier did during the Christmas break of 1940. Bardeen appreciated Nier’s help in getting his paper to the Columbus, Ohio, meeting of the American Association for the Advancement of Science, but he wished that his department would do more to support faculty travel to conferences. Nier was one of many nuclear physicists then studying ura- nium fission, a phenomenon that opened the possibility of building an atomic bomb. Those who knew about fission worried that Nazi scientists might build such a bomb. To do so, as things were under- stood at the end of 1940, one had to first separate a substantial amount of the rare, highly fissionable, uranium isotope of mass 235, from the more abundant isotope, 238U, found in natural ura- nium. With only three units of difference in atomic mass, the sepa- ration of these isotopes was extremely difficult. One of several possible methods for separating the isotopes was thermal diffusion. Nier asked Bardeen to help him develop a theory for the diffusion process. Nier also worked extensively on an electromagnetic isotope separation method, after Enrico Fermi asked Nier to prepare some 235U to use in his research at Columbia University. Fermi suggested that Nier obtain the 235U using the mass spectrometer that Nier had developed to separate isotopes. Nier was successful. He wrote, “On Friday afternoon, February 29, I pasted the little samples [collected on nickel foil] on the margin of a handwritten letter and delivered them to the Minneapolis Post Office.” Two days later he was awakened “by a long-distance tele- phone call from John Dunning,” who had bombarded Nier’s 235U samples with neutrons from the Columbia cyclotron. Dunning “clearly showed that 235U was responsible for the slow neutron fis- sion of uranium.” An article about Nier’s triumph was featured on May 5, 1940, in the Minneapolis Star-Journal. Jane sent a clipping to her mother, who had met Nier on one of her visits to Minnesota. “Looks like a Hollywood version of the earnest young scientist, doesn’t it? The work he has done is extremely important.” In 1940 and 1941, the United States military began to prepare for the nation’s nearly inevitable involvement in the war. Calls to mili- tary research laboratories disrupted the families of many American physicists. Faculty who were not called into service assumed extra 

96 TRUE GENIUS duties. “John is teaching Will Wetzel’s geophysics course and so is very busy here,” Jane wrote to her mother in late 1940. Around the same time, Lynn Rumbaugh was called to the Naval Ordnance Laboratory (NOL) in Washington, D.C. He left Florence to tend to their three children, with a fourth on the way. Having worked ear- lier at the Department of Terrestrial Magnetism, Rumbaugh “knew a lot about magnetism,” according to Bardeen, and so “was called on an urgent basis to help us do something about the German mag- netic mines.” The Bardeens invited Florence to dinner on her birth- day. Lynn phoned from Washington while she was there to wish her a happy birthday. He had written her that “John had been slated to go down there too, but the Navy decided they had better not take three men from the same department.” John and Jane were relieved, but they also knew it was but a temporary reprieve. Jane dreaded a separation from John. “It is a completely new experience for me to be alone,” she had written earlier when he was away at a conference. “Our only other separation was when Jimmy came.” She feared that she “would be less courageous than Florence if he should be called ‘to the wars.’” Although they wel- comed the money that a summer of defense work might bring, Jane wrote to her mother that she “hate[d] to think of being a widow for the whole summer.” John’s sister Helen caused additional worry. In late 1939, to avoid the dampness of the coast, she moved with Donald and Glenis to McBride in the Canadian Rockies. With Helen so often in hospitals, her marriage deteriorated. A few months later, Donald asked for a divorce, relating that he had fallen in love with a nurse at work “All of us are heartsick at the trouble Helen has had,” Jane wrote. Jane and John considered taking care of four-and-a-half-year- old Glenis for a while. They discussed the matter with John’s step- mother Ruth. Donald clearly could not cope with his ailing wife, small daughter, growing medical practice, and now his new love. They doubted that Helen “will ever be well again—and even if the T.B. is arrested she will certainly not be able to earn hers and Glenis’s living.” They also discussed the possible consequences of Helen’s death. John agreed that he and Jane should offer to take Glenis, but that if Helen died, Glenis “should live with her father.” After a flurry of correspondence in December, Helen sent a tele- gram to John and Jane one Thursday evening in January 1941 to say 

Academic Life 97 that “Glenis would arrive Friday morning on the night plane from Seattle.” Jane met the plane, as John “had a first hour class he couldn’t cut on such short notice.” She found her new charge to be “the most unconcerned small person, just put her hand in mine and came home with me. Has all the poise of a woman of the world and takes flying alone hundreds of miles right in her stride.” But the child’s adjustment was not smooth. “Being an only child,” Jane noted, “she and Jimmy (who has also had that handi- cap) don’t get along together in complete harmony.” Jane sent Glenis “to the University nursery school so that she will have play- mates of her own age and can be helped by persons skilled in child care.” Jane confided to her father that “she has tried to see just how much she could get away with, but I think she accepts me as boss now. She obviously needs a lot of loving and I try to give her all I can without turning Jimmy into a green-eyed monster. Her coming, of course, has meant a rather violent change in his way of life, particularly in his emotional self.” Whether or not Glenis and Jimmy ever got past their initial jealousy is not recorded in Jane’s letters, but in later years Glenis recalled the time with Uncle John and Aunt Jane as a period of serenity in an otherwise troubled childhood. She remembered laughter and the sounds of Beethoven, Mozart, and Brahms wafting from John’s phonograph by the living room window. In February, less than a month after Glenis arrived, a new per- turbation added to the worries of war and family. “I shall not see the doctor for a month or so, but I am unmistakably pregnant,” Jane wrote to her mother in early 1941. “I think John would like another boy so he could be pals with Jimmy, but it makes no differ- ence to me.” Bardeen worked on his physics through all the family turmoil. After completing his review of electrical conductivity, he focused his attention on superconductivity. He hoped to explain the London theory on first principles. Heisenberg’s uncertainty principle—that there is a specified limit to the accuracy with which two “conju- gate variables,” such as position and momentum, can be measured at the same time—suggested that if he could explain the observed diamagnetism of superconductors, an account of the infinite con- ductivity would also emerge. 

98 TRUE GENIUS He suspected that Walther Meissner and Robert Ochsenfeld’s demonstration that superconductors expel magnetic fields was a manifestation of the fact that the electrons inside superconductors move in much larger orbits than anyone had thus far realized. He tried to construct a theory, assuming that the only electrons he would have to include were those whose momentum differed little from electrons at the edge of the Fermi surface. He hypothesized that the diamagnetism of superconductors arose from a surface cur- rent involving electrons with large orbits traveling in the neighbor- hood of the Fermi surface. If the electrons at the surface ran around in such a way as to create a field in the opposite direction to the applied field, electrons inside would not feel the applied field. Building on this intuitive picture, Bardeen assumed that when circumstances are favorable, small displacements of the ions inside superconductors cause the electrons to gain an amount of energy that more than compensates for the energy spent on ionic displace- ment. The disparity between these energies, he argued, would cause gaps to form in the electronic structure near the Fermi surface. Drawing on the London theory, he hoped to explain superconduc- tivity in terms of these gaps. Unfortunately, when he tried to for- mulate this theory in three dimensions, the numbers were off by more than a factor of ten. Bardeen sent a version of his new theory to Seitz, who in turn showed it to Wolfgang Pauli when both were in Ann Arbor during the summer of 1941 at the annual Michigan Summer School in Theoretical Physics. Pauli “shook his head in disapproval,” accord- ing to Seitz, who wrote back to his friend, “You haven’t made the grade with Pauli.” Once again Bardeen did not commit his calcula- tion to print, choosing to publish only an abstract. Bardeen would have worked further on the theory, but in March 1941 he was, as expected, called by the Naval Ordnance Labora- tory. By the summer of 1941 he was working in Washington, D.C. But as he studied war-related problems, “the concept of somehow getting a small energy gap at the Fermi surface remained in the back of my mind.” With characteristic tenacity, Bardeen held on to that nagging idea.