Leo Szilard, the physicist who conceived the nuclear chain reaction, kept a small photo of a lost love.
The picture is wallet size. Its surface is cracked, and its edges are worn, as if it had been carried in a wallet. It might, in fact, have been in Szilards pocket on that September day in 1933 when he was walking in the streets of central London and — at a stoplight at the corner of Southampton Row — had the chain-reaction idea that would change the world.
Her name was Gerda Philipsborn. Szilards brother Bela first told me how Leo fell “head over heels” in love with her in Berlin in the 1920s. She was, he said, the daughter of Szilards landlord. Bela remembered her as “a very attractive dark-haired, dark eyed slim Jewish girl whom I have met only once or twice in Leo’s company. She was a very serious person, apparently devoted to the world’s needy or downtrodden, because of which she left... for India to do some work there as a volunteer.” 1
Beyond that, Bela knew nothing about her. He later collaborated with William Lanouette on a biography of his brother titled Genius in the Shadows, but Lanouette’s research discovered very little more. 2
Gerda Philipsborn was a mystery. Every inquiry seemed to lead to a dead-end. As it turned out, it would require an enormous research effort to find the story of Gerdas life, and her role in Szilard’s.
I could not have told the story that follows without the help of Gerdas nephew Gerry Brent and her nieces Ellen Berger and Renate Strauss. In India, I am especially grateful to Tabish Qureshi and M. Zahid.
Leo Szilard rented a room in the Philipsborn family apartment at 95 Prinzregentenstrasse in Berlin on October 1, 1927. 3
Earlier that year, Szilard had become a Privatdozent — a lecturer or instructor — in physics at the University of Berlin. To earn that position, he had submitted a paper on the thought experiment called Maxwells Demon. His solution defined the unit or bit of information.
Since arriving in Berlin from Budapest in 1920, Szilard had shown outstanding promise as a physicist. His doctoral dissertation on thermodynamics had impressed even Albert Einstein, and was awarded the notation eximia, the highest honor. 4 In 1924, Nobel Laureate Max von Laue selected him for a three-year appointment as his assistant at the Universitys Institute for Theoretical Physics.
In 1926, Szilard began collaborating with Einstein on a most unusual project — designing novel household refrigerators with no moving parts. Einsteins interest in inventing had continued after his work as a clerk in the Swiss patent office decades earlier, and he found an equally inventive partner in Szilard. 5
Szilards hosts in the apartment were 75 year old Jacob Philipsborn and his 67 year old wife Ida. 6 Though once wealthy, their savings had been wiped out by the disastrous postwar inflation. 7 Jacob continued to operate his clothing manufacturing business, but like many formerly well-to-do Germans he had chosen to rent out a room for extra income.
There was also another resident of the apartment — the Philipsborns 32 year old daughter Gerda. She was three years older than Szilard, and she was as Bela described her to me: an attractive, dark-haired, dark-eyed slender young Jewish woman. She was also highly intelligent and talented, with a strong social conscience.
On November 4, 1927, only a month after Szilard moved into the Philipsborn apartment, Gerdas mother Ida died of pneumonia. 8 When Gerda filled out an application for her mothers burial at Berlins Weissensee Jewish cemetery, Gerda listed her own occupation as opera singer. 9
Gerda was indeed an opera singer — and much more.
Gerda Philipsborn was born in Kiel, a seaport on Germany’s Baltic coast, on April 30, 1895. 10 She was the youngest of four children. Her brother Artur had been born in 1883, followed by her sister Liese (Lizzie) in 1886, and her sister Clara (Claire) in 1890. 11
Her father Jacob, like most people with the surname Philipsborn, had been born in Bentschen, in eastern Prussia. 12
Her mother Ida, the daughter of a banker, had been born in Cassel into the prominent Mond family. 13 Idas cousin Ludwig Mond, a German chemist, had moved to Britain in the 1860s and built an industrial empire. 14 His companies, Brunner Mond and Mond Nickel, had made him fabulously wealthy.
Jacob Philipsborn, though not an industrial titan, had been successful as a manufacturer of naval and military clothing.
Jacob was a self-made man, Gerdas nephew Gerry Brent recalled. At one point he had over 100 people working for him. Outfits for the merchant Navy. He had a contract for all German colonial troops. West and East Africa, New Guinea... a considerable empire. All colonial troop uniforms were made by my grandfather. 15
By 1903, the Philipsborns had moved from Kiel to Berlin. Gerdas sister Lizzie married and started a family. Her brother Artur decided to become a doctor, and received his medical degree from the University of Berlin. His skills were soon put to use during World War I as a medical officer in the German army. 16
Meanwhile, Gerdas beautiful singing voice, and her talent for music, led her to choose a career in opera. She trained as a singer in Munich, and studied under the famous conductor Bruno Walter. 17
She became a first-class opera singer, and performed classical roles in Munich, Rostock, and other cities. 18 She found, however, that her success gave her little satisfaction. Her greatest desire was to work for a better world, to help others, the less fortunate, and especially children.
Two months after Szilard moved into the Philipsborn apartment, he and Einstein sold one of their refrigerator patents — an absorption-type design with no moving parts — to a division of the Swedish company Electrolux. 19
For Szilard, the Philipsborn home would have been an ideal residence, even without the presence of Gerda. It was a luxury apartment only a few blocks from Einstein’s apartment on Haberlandstrasse, and a short walk from the University.
Gerry Brent, the son of Gerda’s oldest sister Lizzie, recalled going often to the Prinzregentenstrasse home. “It was on a nice street with lots of trees.” He remembered it as having “maybe six rooms, plus maid’s quarters. There always would be a maid, who did cleanup and cooking.”
“When Ida was alive,” he said, “the Prinzregentenstrasse home had much entertaining. There were many people there when we came.”
Gerda’s niece Ellen Philipsborn Berger, the daughter of her brother Artur, visited less often, and thought that “their home had a forbidding atmosphere. Jacob was forbidding. It was a formal household, we had to be on our best behavior... They were quite well off. The apartment had heavy furniture, heavy drapes, not much light. Very forbidding. Very bourgeois, very conventional.” 20
Gerry Brent did not find his grandfather Jacob at all forbidding. “He wasn’t gruff and authoritarian. He was a kind soul, actually. He used to take me to the circus for my birthdays.”
For Szilard, the apartment became much less important than the young woman in it. Probably no one was more surprised by that than Szilard himself. He seemed to view emotionally close relationships — with either men or woman — as a hindrance. Above all, he wanted to avoid being trapped in the domesticity of marriage. As he had told a would-be girlfriend years earlier in Budapest, he had no intention of marrying because he had “too many things to do in life.” 21
Gerda was different, and so, over time, were his feelings for her. She, too, had not married because she had too many things to do in life. In the coming years, his commitment to her would become so strong that he would be willing to follow her personal vision rather than his own.
Gerda loved children. She believed so strongly in the importance of early childhood education that she opened her own kindergarten in the mid-1920s.
She was my kindergarten teacher, Gerry Brent recalled. It was a shop-front kindergarten in [the Berlin district of] Wilmersdorf in the west end. Close to where we lived. We walked there. We would sing songs, do painting.
The kindergarten, however, was not her main interest. Nor, any longer, was opera. She remained a favorite of conductor Bruno Walter, who would unfailingly send her two tickets to his Berlin concerts. 22 Her interest in performing, however, had waned. People asked her if she wouldnt sing opera professionally, Gerry Brent recalled. She shrugged and said, perhaps.
She had found a higher calling through Dr. Siegfried Lehmann, a young children’s doctor who in 1916 had founded the Jüdische Volksheim. The Volksheim, or Peoples Home, was a community center for Jewish refugees flooding in from war-torn Eastern Europe. Located in the ghetto section of Berlin, it offered a school for refugee children and orphans. 23
In 1919, Lehmann had expanded his efforts by setting up a shelter for Jewish war orphans in the Lithuanian city of Kovno.
Gerda took up Lehmanns cause of Jewish orphans as her own mission. She considered no task on their behalf to be beneath her. By the mid-1920s, she could sometimes be seen carrying donated items through the streets of Berlin by hand or on a cart like a common laborer. 24
Lehmann had an even greater dream, to resettle the orphans outside Europe, to the Jewish promised land. In 1927, he founded the Ben Shemen Youth Village in Palestine.
When Szilard came to live with the Philipsborn family, the Ben Shemen Youth Village was Gerdas greatest cause. 25
Szilard was so full of new ideas that he was known for offering them freely to friends and colleagues.
One day in early 1928, at the Café Wien, Szilard startled fellow Hungarian physicist Dennis Gabor with yet another new idea.
Louis de Broglie had proposed that electrons had a wavelength, he pointed out, and Hans Busch had shown that it was possible to make electron lenses.
“Why don’t you make an electron microscope?” Szilard asked. “One could see atoms with it.”
Gabor, to his own everlasting regret, dismissed the idea as impractical. “What is the use of it?” he replied. “One cannot put living matter into a vacuum, and anyway everything will burn to a cinder under the electron beam.” 26
At the University, Szilard was teaching a seminar on recent work in quantum theory with fellow Hungarian John von Neumann. 27
In his spare time, a new world of companionship had opened. Just as Szilard knew everyone in the sciences, Gerda knew everyone in the arts and society. In her company, it was possible to attend all the finest cultural events, from operas and concerts to plays and art exhibits. 28 If Szilard was not especially interested in those activities, her enthusiasm was hard to resist.
In addition to her other talents, Gerda was a skilled typist, and knew shorthand. She began helping Szilard with his correspondence.
In the fall of 1928, Szilard and Einstein scored a major success in their collaboration. The A.E.G., the German General Electric Company, agreed to develop the Einstein-Szilard electromagnetic pump — a pump without moving parts — for use in home refrigerators. They hired Szilard to direct the work as a consultant. 29
In late November 1928, Gerda went to London for an extended fund-raising tour for the Ben Shemen Youth Village. 30 Her contacts with her Mond relatives there gave her access to the highest social circles in Britain.
In 1926, the Mond companies had merged with others to form Imperial Chemical Industries, one of the world’s largest industrial corporations. Alfred Mond, the first chairman of the new I.C.I., was honored with a peerage in 1928 as Baron Melchett. His daughter, Gerda’s second-cousin Eva Violet Mond, was already by marriage the Viscountess of Erleigh. (She later became the Marchioness of Reading.) 31
In Berlin, in Gerda’s absence, Szilard worked on patent applications for new inventions — the linear accelerator and the cyclotron. Such devices, by accelerating particles to high speed, would allow physicists to study the atomic nucleus. He filed for patent on the linear accelerator on December 17, 1928. He filed for patent on the cyclotron on January 5, 1929. 32
Early in 1929, he wrote to Gerda in London about a problem that was bothering Einstein. A new British company was calling itself “Einsteins Electro Chemical Process Limited,” and leaving the impression that he was associated with the company. 33
After receiving Szilard’s letter, Gerda immediately wrote to Einstein on February 3 offering the services of her cousin Dr. Albert Mond, a prominent London attorney. 34
In late March, during the spring break at the University, Szilard took the opportunity to visit Gerda at her boarding house in London. 35 Springtime alone with Gerda in the city would have been idyllic. He had, also, a serious purpose on his mind.
During his trip, he had dinner with author H.G. Wells, long one of his favorite writers. 36 Wells latest book The Open Conspiracy matched his own thinking, and it was a call to action.
Wells believed that current governments and social institutions would be unable to deal with the crisis of civilization that he saw coming.
The technology of warfare was advancing at an ever-increasing pace, and humanity might be doomed by a war of self-destruction. “I am discussing,” Wells wrote, “whether our species... is to live or die.”
Wells proposed a “conspiracy” of individuals willing to devote their lives to averting that disaster. If it did not work, there might be no second chance. “The ultimate decision of the fate of life upon this planet,” Wells wrote in conclusion, “lies now in the will of man.” 37
A year after her first trip, Gerda returned to London for a second fundraising tour for the Ben Shemen Youth Village. 39 As he had done before, Szilard visited her there during spring break at the University.
This time, he had an ambitious plan for an organization of his own that he called the Bund — the League or Alliance. Wells had proposed no specific way in which his Open Conspiracy would be implemented. Szilard’s ideas had become more specific.
The Bund, as Szilard conceived it, would start with students in universities. Beginning with only a small number of talented individuals, it would start as a seed crystal around which a larger movement could coalesce.
At first through their influence on their fellow students, and then by taking career positions in important fields, members eventually could shape the policies of governments.
Most important was the selection of Bund members. To ensure that they were motivated by altruism, he emphasized the necessity of personal sacrifice. 40
Germany, however, did not have enough time for a salvation effort that might take a generation.
In the September Reichstag elections, the tiny Nazi party received almost 20 percent of the vote. Szilard foresaw the future. On September 27, 1930, he wrote to Einstein. “From week to week I detect new symptoms, if my nose doesn’t deceive me, that peaceful [political] development in Europe in the next ten years is not to be counted on... Indeed, I don’t know if it will be possible to build our refrigerator in Europe.” 41
That winter semester, he taught two seminars, one on theoretical physics with Erwin Schrödinger and John von Neumann, and another on atomic physics and chemistry with Lise Meitner. 42
In mid-1931, he was reminded of the electron microscope he had proposed to his friend Dennis Gabor three years earlier. Two young engineers, Max Knoll and Ernst Ruska, had begun building a device that they did not yet even call a microscope. As Knoll described it in a public lecture on June 4, it was barely more powerful than a hand magnifying glass. 43
From such humble beginnings, Szilard was reminded of the promise he had described to Gabor of a microscope powerful enough to see individual atoms. He filed a patent application on his own designs a month later, on July 4, 1931. 44
In the fall of 1931, he was offered a year-long position to work on problems of quantum theory at Princeton University. 45 His friends Eugene Wigner and John von Neumann had already begun working there for half of each year.
The idea of spending a year away from Gerda was out of the question, but he was willing to spend a few months.
Most important, the offer allowed him to apply for an immigrant visa to the United States. On October 19, 1931, he wrote to Einstein, who was vacationing at his summer house in Caputh, for a letter of recommendation to the American consulate.
Gerda added a postscript to Szilard’s letter, explaining that she was signing it for him with apologies. Szilard had dictated the letter to her in shorthand, she wrote, but he hadn’t yet returned to sign it. 46
Taking time off from the University, where he was scheduled to teach seminars with Schrödinger and Meitner, he docked in New York on Christmas day 1931.
In Princeton, the highly mathematical abstractions of quantum theory could not hold his interest. Though he was the originator of one of the most important features of quantum theory — the idea that measurement itself determined quantum states — he was less concerned with working on details. Wigners spirits fell when Szilard said that quantum theory “did not offer him enough.” 47
At the moment, he was more worried about the world situation. Japan had invaded China in September, facing the League of Nations with its first great test. The structure of the postwar peace was being challenged, and it was already doubtful that the challenge would be met. In February, as Japan attacked Shanghai, he drafted a statement for the signature of leading scientists pledging scientific non-cooperation with Japan. 48 Scientists, however, proved no more willing than politicians to take action against the invasion.
Back in Berlin in early May, he rejoined Gerda and her father Jacob, who had moved to a new apartment on nearby Motzstrasse.
For Szilard, it was a summer of disappointments.
In the July elections, the Nazi party won 37 percent of the vote, making them the strongest party in the Reichstag. Though they could not rule, they could paralyze the government, and they continued to demand more power.
Despite his years of work on the Einstein-Szilard refrigerator, its development was ending. It had fallen victim to the American invention of non-toxic Freon refrigerant, and the deepening Great Depression. In August, the A.E.G. Heat Engineering laboratory, where prototypes had been built, was closed entirely. 49
His greatest disappointment was the most personal. By applying for American immigrant status, he had laid the groundwork for a future in America. Gerda, however, had decided on a different plan.
After years of talking about going to India, Gerda had made her decision to go. She had a specific destination in mind — the same one she often talked about. It was in Delhi, and it was called the Jamia.
Gerda had long been inspired by Mahatma Gandhis non-violent struggle for Indias freedom from British rule. 50 In the mid-1920s, through that interest, she had met Zakir Husain, a brilliant and charismatic student from India who had come to Berlin to work on a doctorate in economics. 51 Husain had returned to India in early 1926 to devote himself to the struggling Jamia Millia Islamia (National Islamic University).
The Jamia had been founded in 1920 in response to Gandhis call to boycott educational institutions run by the British colonial government. 52 Gandhi had provided funding for a year at a critical time, but after that it was on its own. 53 It was desperately impoverished, on the brink of bankruptcy and closure.
By 1932, Husain was vice-chancellor of the Jamia, which was as impoverished and threatened as ever. Husain had warned her not to come — that the conditions in India would be too hard for her. 54 Still, Gerda was determined to help where she believed she was needed most.
On a painful day in September 1932, Gerda left for the Ben Shemen Youth Village in Palestine, on her way to India. 55
Szilard was devastated, and miserable without her. He immediately began trying to find a job in India so that he could join her there.
On October 8, he wrote a soul-searching letter to his friend Wigner. 56
How, he wrote, could one in good conscience devote oneself to science when there were more pressing problems to be solved in the world?
“Of course physics interests me ten times as much as ice machines... But is that the passion which moves mountains?”
On a temperature scale of 100, he wrote, where the boiling point was defined “by my interest in physics when I was 18 years old, then I’m right now about 30 degrees.”
What he wanted, he wrote, was a job that “allows one enough free time to be able to give attention to those things one finds important. A good solution may be a chair in experimental physics in India...
“Until I could get such a position, I would have a bad conscience pursuing science.”
He had, he said, “written to India.”
On October 23, after five years of living with the Philipsborn family, he packed his bags and checked into the Harnack House, the faculty club of the Kaiser Wilhelm Institute. 57
For winter semester, starting in November, he was scheduled to teach a seminar with Schrödinger on recent developments in theoretical physics. Instead, he withdrew from the seminar, and waited for a job offer from India. 58
Gerda arrived in India at Bombay on December 21, 1932. 59 Zakir Husain met her ship, and accompanied her on the train to Delhi. She was officially appointed to the staff of the Jamia on January 1, 1933. She was assigned to the Primary School and the hostel for the smallest children. 60
In the Berlin that she had left behind, Szilard had received visitors from New York.
Benjamin Liebowitz, a physicist and inventor whom Szilard had met in America, arrived in Berlin at the beginning of November for a year of advanced physics study. Liebowitz expected an enriching cultural experience and had brought along his wife and two teenage daughters.
Szilard found them a place to live and introduced them to Gerda’s brother Artur and his family. Arturs wife Regina was a psychotherapist who had studied with Alfred Adler, and she began counseling Liebowitz troubled 14 year old daughter Elsbeth. 61
On January 30, 1933, Germanys aging president yielded to the Nazi’s power and appointed Adolf Hitler as Chancellor.
Szilard thought it safest to take a trip home to Budapest. When he returned three weeks later on February 24, he tried to convince friends to leave Germany as soon as possible. 62
Even one of his best friends, fellow Hungarian Michael Polanyi, was unable to accept the reality of the danger. Polanyi had been considering a professorship offer in England, but he had decided to decline and stay in Berlin. 63
Gerdas brother Artur, however, and Benjamin Liebowitz, heeded Szilards warnings. Artur sent his wife and three daughters to safety in Denmark, and Liebowitz’ daughter Elsbeth went with them. His other daughter soon followed. 64
Day by day, the Nazi grip tightened as opponents disappeared into jails and detention camps.
On March 31, Szilard himself boarded a train to Vienna. 65 The next day, April 1, was proclaimed as a national “Day of Jewish Boycott.” Nazi thugs stood guard in front of Jewish businesses and Jews were beaten on the street. The next train to Vienna was jammed with fleeing refugees. It was stopped at the German border and the passengers were removed for interrogation by the police. 66
The Jamia was located in Karol Bagh, an isolated suburb of Delhi without electricity or running water, and little hope of cleanliness or comfort. 67
In that environment, depressing even to its residents, Zakir Husain had introduced Gerda to the small children now under her care.
One of those children, Obaidul Haq, recalled the introduction. “This is your Aapa Jaan who has come from Germany,” Husain told them. “She will stay with you and look after you.” 68
In Urdu, Aapa Jaan was an affectionate term meaning Elder Sister or Dear Sister, and that was the name by which Gerda became known there.
Though the Jewish German woman dressed in European clothing seemed strange to the children at first, she quickly won their trust by treating them as lovingly as if she were their own mother. 69
In interviews conducted by my colleague M. Zahid in Delhi, retired Jamia staff members Obaidul Haq and Shoebur Rehman recalled their experiences under Gerda’s care. 70
They agreed that she loved children very much and spent all her time keeping them neat and clean, even sewing and mending their clothes. She bathed them regularly. Haq identified himself in a group photograph, taken after she had bathed them all in a large water tank.
Gerda improved their lives in every way. She introduced periodic health check-ups for all children, and organized new extra-curricular activities including Theater, and Arts and Crafts.
She used her Agfa box camera, Obaidul Haq recalled, to teach them photography. When the children had taken their pictures, she would travel with them across town to a photo shop in Kashmiri Gate for developing and printing.
In Vienna, and then soon afterward in London, Szilard began organizing a support effort for the flood of academic refugees from Germany that he expected.
On April 7, the Nazi government announced a Civil Service Law banning “non-Aryans” from state positions. University faculty were civil service, and the announcement meant that some of Germany’s most prominent scientists and scholars were to be dismissed. Nobel Laureates were no safer than their assistants.
In London, Szilard checked into the Imperial Hotel on Russell Square and continued contacting influential individuals and organizations. Many were the same ones that Gerda had approached in her fundraising for the Ben Shemen Youth Village.
The number of dismissals soon mounted into the hundreds. In late May, partly as a result of his efforts, the Academic Assistance Council was formed in London with physicist Sir Ernest Rutherford listed as its official President. From two small rooms in the offices of the Royal Society, the Council acted as an employment agency and clearinghouse for the refugee scholars, helping to resettle them to jobs in new countries. 71
Working without an official position, and at his own expense, Szilard coordinated relief efforts among various groups. He shuttled back and forth to the continent, visiting France, Belgium, and Switzerland, to gather information and recruit support.
As his rescue efforts continued through the summer, Gerda may have been writing to ask him why he had not yet come to Delhi, and if he had dismissed the idea of coming.
He still wanted to join her in India, but he was unwilling to go there without a means of supporting himself. He had yet to find such a job. Though it would be easier to find a short-term fellowship than a faculty position, he was reluctant to risk being stranded when the fellowship ran out.
On August 11, he wrote apologetically to Gerda from the Academic Assistance Council office that he was so busy helping the Council that he could not consider his own personal life. “I have not dismissed the idea of going to India, neither has this idea grown stronger... I do not know if it would be wise to go to India for two years with a small English fellowship unless I were determined to stay there whatever happens.” 72
One month later, on September 12, 1933, he read an article in the London Times reporting a speech by Ernest Rutherford.
Rutherford had declared that dreams of atomic energy would remain only dreams. The Times reported that Rutherford had said that “anyone who looked for a source of power in the transformation of the atoms was talking moonshine.” 73
Irritated by Rutherford’s remarks, Szilard brooded on the subject while walking through the streets of central London. He thought especially about the recently discovered neutron, which had no electric charge and could enter the atomic nucleus without resistance.
Looking up at a stoplight at the corner of Southampton Row, it suddenly occurred to him that if an element existed that released two neutrons after being struck by one neutron, the result would be a neutron chain reaction. 74
It would spread automatically, multiplying from one atom to the next, liberating energy with each step, liberating neutrons, more energy, more neutrons. If left uncontrolled, in a mass above a certain critical size, it could explode with incredible force.
Such a discovery would mean not only atomic energy, but also atomic bombs. H.G. Wells had predicted exactly that in his 1914 novel The World Set Free. The book was fresh in Szilard’s mind from reading it only a year earlier. In Wells’ story, the discovery of atomic energy led to a war fought with “atomic bombs” that almost destroyed civilization. Finally, wiser minds prevailed to form a world government. 75
In fiction, or in fact, it was obvious that the discovery of atomic energy would change the world. It would be one of the most important discoveries in history.
Still — on the one hand was atomic energy, and on the other hand was Gerda Philipsborn.
He chose Gerda. He had asked the Academic Assistance Council staff to alert him to any job openings in India, and he continued to follow up on the offers they provided. One was in Bangalore, a long train ride from Delhi, but at least in India. He even investigated and considered a job opening as a tutor in mathematics and physics for a wealthy Indian family. 76
In early January 1934, the Council informed him of an opening in Delhi itself. Szilard replied on January 9 that “I had also direct information from friends in Delhi...” Airmail to India left only once a week, he explained, and he had missed that flight, but he expected that later applications would be considered. 77
In mid-January, French researchers Frédéric and Irène Joliot-Curie in Paris reported the discovery that bombardment with positively charged alpha-particles could produce artificial radioactivity. Szilard immediately realized that the reaction could be done much better with neutrons. Still, that did not change his desire to go to India.
On January 29, 1934, he wrote to his friend Michael Polanyi, “I have written to Delhi offering to visit Delhi if they should decide that they would rather have me in preference to other candidates, and that I could decide on the spot.” 78
His description of the University of Delhi, and the job there, made it clear how much he was willing to sacrifice to get a job in Delhi. The University, he told Polanyi, was not even a full University. The physics department there almost did not exist. There were no professorships, and the salaries were very poor.
The name of the man who received the job at the University of Delhi may have been forgotten by history. It was not Szilard.
Unable to find a job in India, he concentrated on his ideas for the chain reaction.
He knew that the same idea could be conceived by others. The best he could hope for was if atomic energy could be developed first in democratic countries. He also knew from experience that a patent would be necessary to gain the support of individuals and companies who might be willing to fund the necessary research.
On March 12, 1934, he filed British patent application 7840/34 on the “Transmutation of Chemical Elements.” 79
To test his ideas, he needed a laboratory, and Britain’s best physics laboratory was Rutherfords Cavendish Laboratory at Cambridge. On June 4, he met with Rutherford to ask for research space there. The outcome was predictable. “Surely I have explained often enough,” Rutherford boomed to persistent questioners, “that the nucleus is a sink, not a source, of energy.” 80
Even while preparing another patent application on the chain reaction, he was still thinking about Gerda. On June 16, 1934, he sent a money order to Delhi for 10 pounds, 3 shillings and 3 pence. It was a substantial sum — enough to pay for his room at the Strand Palace Hotel for an entire month. Ten days later, on June 26, he sent her another money order for the same amount. 81
His best candidate for a chain-reacting element was beryllium. Without a laboratory of his own in which to perform experiments, he arranged to use the research facilities of Londons St. Bartholomew’s Hospital. His discoveries there promptly established his reputation as a nuclear physicist.
As his experiments continued, however, it became apparent that beryllium was unlikely to sustain a chain reaction.
In the spring of 1935, Frederick Lindemann, director of Oxfords Clarendon Laboratory, arranged him a refugee fellowship from Imperial Chemical Industries, the giant company founded by Gerda’s Mond relatives. 82 The fellowship allowed him to begin research at Oxford on his next candidate for a chain reacting element, the element indium.
By 1936, it was clear that Gerda was not going to leave India, and Szilard would not be joining her there.
Szilard’s thoughts turned to a young Austrian woman he had first met in January 1930, when Gerda was in London on a fundraising trip and he had needed more secretarial help. Gertrud (Trude) Weiss had done some typing for him and asked for career advice. He had recommended that she return to Vienna to study medicine. 83
Trude had taken that advice, and was now finishing her medical degree. When she wrote to him seeking advice about her future, he wrote to her on March 26, 1936 that she should come to England. In two years, he predicted, she would be unable to continue to live in Vienna. She heeded his warning, accepted his invitation, and soon joined him in England. 84
He had divided his patent applications into two categories, those involving single-neutron reactions, and those involving the chain reaction. To keep his chain reaction applications secret, he had offered them to the British War Office. The War Office, however, found “no reason” for secrecy. 85
The British Admiralty finally agreed, but only after it was explained that he was offering his ideas at no charge. With that understanding, his chain reaction patent was accepted as secret on March 30, 1936 and withheld from publication. 86
He had been unable to find any companies willing to properly fund his research. Convincing his colleagues was just as difficult.
He tried to persuade leading nuclear physicists to unite to control work in nuclear physics that might have dangerous applications. None were interested, and none saw a danger. 87
For such an agreement to succeed, it especially needed the participation of Enrico Fermi, whose research in Mussolinis Fascist Italy was establishing him as a leading expert on neutron reactions.
Fermi, however, was trying to commercialize a patent he had filed on producing artificial radio-isotopes. Despite Szilards pleas, Fermi had no interest in hypothetical chain reactions or in joining Szilard’s “conspiracy.” 88
In Berlin, Jacob Philipsborn was still operating his clothing business at the age of 84. On January 30, 1937, he was accidentally run down and killed in the street while making deliveries. “He died with his boots on,” Gerry Brent recalled. “Navy pullovers and trousers sent off until the day he died.” 89
In Delhi, Gerda was still a German citizen. On May 26, 1937, she applied for British citizenship. On her application, she noted that “part of the petitioners family resides in the United Kingdom for generations, and includes such well known people as Lady Reading...” 90
Despite such connections, her application was denied because of her association with Gandhi’s campaign for India’s independence. An investigation of her application by the Superintendent of Police in Delhi reported that “in June 1936 she went to Wardha in the C.P. to give lessons in drawing, embroidery and knitting to the inmates of the Ghandhi [sic] Ashram there.”
Noting Gerdas employment with the Jamia, the Police Superintendent wrote that, because it was started as part of Gandhi’s non-cooperation movement, “there is no doubt that all members of its staff hold anti-British views.”
As for Gerda herself, he concluded that “it is probable that at heart her sentiments are not loyal. She does not seem to be a fit person for the grant of a Naturalization Certificate.” 91
Though Gerda was forced to remain a German citizen, at least she was safely outside Germany.
Her sister Claire was also outside Germany, but far from safe. Claire had joined the International Brigades as a nurse in the Spanish Civil War, where the Nazi-backed forces of General Francisco Franco were fighting to overthrow the democratic government.
Claire had become “a firebrand” against Nazism and Fascism, Gerry Brent recalled. “I would not be surprised if she herself picked up a gun.” 92
In Germany itself, life for Jews was increasingly grim. One day Gerry Brents father ran into a police sergeant acquaintance at a tobacconist shop. “Tomorrow we’re coming for your son’s passport,” the policeman warned him. Gerry escaped overnight to Denmark. In three weeks, he got a British visa guaranteed by Sir Robert Mond. 93
Szilard had concluded that even Britain would not be safe in the coming war. He arrived in New York on January 2, 1938. Trude Weiss, who had just arrived, was there waiting for him.
On March 12, Hitlers troops rolled unopposed into Austria and it was declared to be a province of Germany. Szilard sent a three-word telegram to his brother Bela in Budapest — NOW OR NEVER. 94 Bela arrived in New York the next month, but getting visas for his family took longer.
Gerda’s brother Artur, his wife Gina, and their three daughters (Ellen, Renate, and Nora), had spent the last five years in safety on the Danish island of Bornholm. They had remained in Denmark in the hope that Hitler would not last. Finally, however, they abandoned that hope, and Szilard’s friend Liebowitz rescued them.
“Ben Liebowitz really liked my Mom,” Renate Philipsborn Strauss recalled. “He gave us the affidavit that allowed us to come to the U.S.A.. The Liebowitzes saved our lives with the affidavit.” Artur and his family arrived in America on April 5, 1938, and settled in Berkeley, California. 95
Gerry Brent’s parents (Gerda’s sister Lizzie and her husband), waited even longer and had much greater difficulty escaping Germany. At the last minute, Ludwig Mond’s brother-in-law Robert Mathias paid for their passage to Australia. 96
The announcement in January 1939 of the discovery of uranium fission gave Szilard the chain-reacting element he had been seeking. At New York’s Columbia University on March 3, he performed an experiment showing that each fission released more neutrons.
Newspapers and magazines began to speculate about the prospect of atomic energy from uranium. Almost all physicists, however, continued to believe that atomic energy and atomic bombs were improbable or impossible.
Still unable to find support for his research, and concerned that Germany might gain an unbeatable lead in developing an atomic bomb, Szilard turned to his friend Einstein. The result was a letter from Einstein to President Franklin Roosevelt dated August 2, 1939 warning of the urgent need for an American research program. 97
On September 1, Hitler invaded Poland, and Europe was at war.
In the summer of 1940, Gerda was arrested and confined as an enemy alien. On September 5, 1940, she wrote to her second-cousin Lady Reading asking for her help.
“I am, together with almost all Jewish refugees in India, taken to the Purandhar Camp and others to other camps. We all had offered our services to the Government to do what we can to help in the war against Hitler, but we have all been arrested.”
Almost six months later, on February 27, 1941, Gerda wrote again to Lady Reading. “We are all getting rather desperate and hopeless because nobody seems to care what happens to us... It is so terribly bitter to be not only excluded from helping but also being suspected. I never imagined that something could be so hurting!” 98
With her typical selflessness, Gerda asked nothing for herself, but only for her group as a whole. She also did not mention that she herself was ill. Even before the start of the war, she had begun to experience symptoms that she probably first attributed to the food and water, or local diseases. 99 As the pain in her stomach increased, however, she may have begun to suspect that it was something worse.
Lady Reading’s late father-in-law had been the British Viceroy of India, and her influence was considerable. Despite her efforts, however, the authorities in India continued to delay. Gerda was not released until late September or early October 1941, after spending more than a year in confinement at Purandhar. 100
Szilard, too, was facing internment, though he did not know it. Einsteins letter to the President had produced little more than bureaucratic committees, official skepticism, and a trickle of funding. Years had been wasted as Hitlers armies conquered Europe.
In September 1942, General Leslie Groves was placed in charge of all American atomic research, which had just been given the code-name “Manhattan Project.”
After meeting the outspoken and foreign-accented Szilard in October 1942, Groves drafted an order for Szilard to be arrested and “interned for the duration of the war.” Groves plan was thwarted only because Secretary of War Henry Stimson refused to sign the order. 101
Almost four years after the discovery of fission, Szilard and his colleagues finally obtained enough uranium and pure carbon to build a full-scale test reactor. As assembled at the University of Chicago under the direction of Enrico Fermi, it was essentially the same uranium-carbon lattice design that Szilard had proposed in July 1939.
In the first test of the reactor on December 2, 1942, its nuclear chain reaction successfully became self-sustaining and steadily increased until it was shut down for safety.
“I shook hands with Fermi,” Szilard later recalled, “and I said I thought this day would go down as a black day in the history of mankind.” 102
After her release from Purandhar, Gerda went back to the Jamia, and there were celebrations on her return. 103 She had won the affection and respect of everyone there, from the smallest child to the most senior faculty member. Originally only the children had called her Aapa Jaan, but the name was so fitting that she was called Aapa Jaan — Dear Sister — by all.
She had improved the Jamia in countless ways, and ensured its survival and growth through personal fundraising. She had gotten women out of the traditional seclusion of their homes and involved them in their community. She had advised Zakir Husain for years on educational policy, and her advice had become even more influential when Gandhi placed Husain in charge of his Basic National Education plan. 104
In 1942, she signed the Jamia Life Member pledge, taken by only its most dedicated members, to serve the Jamia for a poverty-level salary of not more than 150 Rupees per month. 105
When the pains in her stomach became severe, she was admitted to a hospital in Delhi. 106
On March 11, 1943, Zakir Husain dedicated his book Talimi Khutbat (Educational Addresses) to her: 107
“To Aapa Jaan, Gerda Philipsborn
Aapa Jaan, the last pages of the book have just been printed. Whatever I have said and the way I have said it, reflects your influence. If you permit me, I would like to dedicate this book to you... You have made a place for yourself in the hearts of the Jamia community but you may not realize how deeply you are revered and loved here...”
When she was finally operated on, the surgeon found her intestines covered with cancer and decided that continuing the operation was futile. 108
Gerda Philipsborn died on April 14, 1943, at the age of 47. 109 She had asked to be buried at the Jamia among her Muslim friends, and her request was granted.
Two glowing tributes to her life were soon printed in the Jewish Advocate, published in Bombay.
In one, a former fellow resident of the Purandhar camp recalled how Gerda had been the bright spot of their confinement:
“Nowhere in India did we attend such an elevating divine service as in Purandhar thanks to Gerda Philipsborn who rehearsed the Jewish songs well known to her from former times and conducted the choir accompanying the singers on the harmonium herself...
“All former co-internees mourning her loss will never forget her wonderful singing voice, but even stronger in memory to all of us sounds in our ears her charming melodious speaking and laughing.”
She was, the writer concluded, “the cleverest, most broadminded and most kindhearted woman I ever came across amongst the European Jews in India.” 110
The Jewish Advocates full obituary was a long and tender remembrance by her friend Anita Kashyap, who recounted Gerdas life as she had learned it from her.
“Her life is like a strange story and one can only wish that someone gifted with narrative powers will write the story of her life and describe its beauty and its richness.”
She was born, Kashyap wrote, “as the child of a rich and well-known Jewish family in Berlin and was brought up in comfort and luxury, apparently destined to become a society girl, make a suitable marriage and lead the life of a great lady.”
Instead she had chosen a musical career, achieved success as a “first-class opera singer,” but given that up because “she could not find any lasting satisfaction in a life which centered around herself.”
She had found that satisfaction, Kashyap wrote, in Berlin in her work for the Volksheim and Ben Shemen, then in India at the Jamia.
Kashyap described her sacrifices at the Jamia: how she had lived there in crushing poverty, asking no special favors for herself, and how she had traveled throughout India by third-class rail seeking donations for the school.
“There will be many people in different parts of the world to mourn her loss, in England, in America, in Palestine, and in India. There will be many whose life has become poorer by the realization that a great heart has ceased to beat and the most perfect friend has gone forever.” 111
Szilard probably learned of Gerdas death soon afterward, either from her brother Artur and his family in Berkeley or less directly from his friend Liebowitz, whose affidavit had allowed their escape from Europe.
After the success of the first chain reaction, Szilards thoughts began to turn to the problem of the eventual use of atomic bombs and the danger of a postwar nuclear arms race. In the spring of 1945 he unsuccessfully sought personal meetings with President Roosevelt, and then after Roosevelts sudden death, with President Truman.
In June, he co-authored the Franck Report, which urged that the atomic bomb be demonstrated “before the eyes of representatives of all the United Nations, on the desert or a barren island.” 112 In July, he circulated a petition against the use of atomic bombs on the cities of Japan. 113
After the war, he founded, with Einstein and others, the Emergency Committee of Atomic Scientists. He strenuously opposed the cold war and nuclear arms race in congressional testimony, speeches, and magazine articles.
In 1947, he turned from physics to the new field of molecular biology, to try to discover the basis of life.
In 1951, he married his long-time girlfriend Trude Weiss. 114 Though married, they continued to live apart — he usually in Chicago and she in Denver — until brought together by his cancer treatment in 1960.
During treatment for bladder cancer — for which he designed his own radiation therapy — Szilard began work on his memoirs. It was a task that must have caused him to reflect on how different his life would have been if he had joined Gerda in India.
Indeed, the course of the nuclear age could have turned on his love for Gerda Philipsborn.
Perhaps out of concern for the feelings of his wife Trude, and also from his lifelong reluctance to discuss his personal life, he did not mention Gerda in the recollections that he completed.
After recovering from cancer, he tried “looking for a market for wisdom” among policy-makers in Washington. Finding none there, he embarked on a coast-to-coast speaking tour titled “Are We On The Road to War?” 115
Months later, in October 1962, the Cuban Missile Crisis brought the world to the very brink of nuclear war, and showed how serious the danger had become. The organization that grew out of his speeches became the Council for a Livable World.
In early 1964, he moved to La Jolla, California to become a Resident Fellow at the new Salk Institute, which he had helped to create.
In a cottage near the ocean in La Jolla, Szilard died in his sleep, with Trude by his side, of a heart attack on May 30, 1964.
In 1967, Zakir Husain was elected President of India.
Gerda Philipsborn is remembered and honored at the Jamia today, where two buildings are named for her. Very little is known there, however, about her life before she arrived in India.
Their main sources of information about her are two accounts written by Mohammad Mujeeb, who was studying in Germany with Zakir Husain when Zakir and Gerda met. One account appears in Mujeeb’s biography of Husain. 116
In the longer account, published in Urdu in the Jamia journal Jauhar, Mujeeb recalled both their meeting and her later life in India.
“Only Miss Philipsborn knows what she lost in India and what she found when she came from Germany,” he wrote.
“The poor and dilapidated condition of the Jamia increased her interest rather than discouraged her... The service of the Jamia was the last mission of her life and she stuck so firmly to it that no one could separate her from it.”
She had sacrificed even her right to romantic love in order to serve the Jamia, Mujeeb wrote. “If a few of the Jamia people could reach her status,” he concluded, “we will be deserving in front of God.” 117
Another source of information about her life at the Jamia is a small booklet in Urdu by Sughra Mehdi titled Bachchon ki Aapa Jaan — Aapa Jaan for Children. 118
By far the most visible reminders of her legacy are the two buildings named for her. One of the Jamias dormitories is named the Gerda Philipsborn Hostel for Girls. The Gerda Philipsborn Day Centre, a day-care center, was opened in 2009. Her portrait is displayed in the Centre. 119
I began this story by describing a small photograph, a wallet-size picture that showed wear at the edges, with many cracks on its surface. It might, I said, have been in Szilard’s pocket on the September day in 1933 when he conceived the nuclear chain reaction on a London street-corner.
I did not mention that it is a group photo, or what is written on the back. On the back is written, in Gerdas cursive handwriting, in German:
“Mit der schwarzen Mütze Zakir nach dem Freitags-Morgen Badefest, wo ich sie immer alle selbst ab schrubbere.” 120
“With the black-capped Zakir after the Friday morning bathing-festival, where I always scrub them down by myself.” 121
It is Friday morning bath-time for the children of the Jamia. In the rear of the picture are three adults. On the left, dressed in black and wearing a black cap, is Zakir Husain. In the middle, dressed in white, her head modestly lowered, is Gerda Philipsborn. The identity of the other man is unknown. Surrounding them are 21 small children of the Jamia Millia Islamia.
Szilard, as I said, saved the photo to the end of his life. It is stored among his papers in the Mandeville Special Collections Library at the University of California, San Diego. It is catalogued there as an “Early Childhood” photo — of Leo Szilard. 122
1) More photos of the Philipsborn family.
2) Letter from Gerda Philipsborn #1 (Purandhar Parole Camp, Poona District, India) to her second-cousin the Marchioness of Reading (Eva Violet Mond Isaacs) (London), September 5, 1940.
3) Letter from Gerda Philipsborn #2 (Purandhar Parole Camp, Poona District, India) to her second-cousin the Marchioness of Reading (Eva Violet Mond Isaacs) (London) February 27, 1941.
4) “JAMIA MILLIA’S LOSS: Death of Miss Gertrude [sic] Philipsborn.” Hindustan Times, Saturday, April 17, 1943.
5) “Gerda Philipsborn,” obituary by Anita Kashyap, Jewish Advocate (Bombay) May 1943, courtesy Gerry Brent.
6) “Gerda Philipsborn,” letter to editor by anonymous author, Jewish Advocate (Bombay) June 1943, courtesy Gerry Brent.
7) Comments by readers. (added June 22, 2015)
8) More supplements may be added later. Check back again, or follow me on Twitter @GeneDannen for updates.
Comments sent to me by email (firstname.lastname@example.org) are welcome, and a selection may be published here. Comments will be kept confidential unless you explicitly state your permission for publication.
TITLE: To See You Again
I apologize to everyone mentioned here for my long delay in publishing this research. I had to give priority to a long-term health crisis in my family.
Because of the passage of time, I have probably omitted some people who helped me. I will try to improve that in future updates.
For interviews, correspondence, photographs, and documents, I am especially grateful to Gerry Brent, Ellen Berger, and Renate Strauss.
For help of every kind over many years, including research, translations, and conducting interviews, I am especially grateful to Tabish Qureshi and M. Zahid, Physics Department, Jamia Millia Islamia, New Delhi, India.
To all the remarkable people around the world named Philipsborn who answered my inquiries when I was trying to trace Gerda, even though they had never heard of her, I offer my sincerest thanks. Rather than risk accidentally omitting names, or violating your privacy, I thank you all collectively. For his continuing interest in Philipsborn genealogy, I am especially grateful to Tom Philipsborn. I apologize to Tom, and to Judith Berlowitz, for having to withhold the results of my research until publication.
I thank Peter Melchett, 4th Baron Melchett, for his kind reply to my inquiry.
For decades of help, I am grateful to Lynda Claassen and all her staff at the Mandeville Special Collections Library, University of California, San Diego.
At the Albert Einstein Archives at the Hebrew University of Jerusalem, now and in the past, I am grateful to Roni Grosz, Ze’ev Rosenkranz, and Barbara Wolff. I also made extensive use over the years of the Albert Einstein Duplicate Archive, Department of Rare Books and Manuscripts, Princeton University Libraries. Robert Schulmann was very helpful in that research.
Material from the files of the Society for the Protection of Science and Learning (SPSL) has been reproduced by the kind permission of CARA (the Council for At-Risk Academics). Thanks to Ryan Mundy. When it was still the SPSL, I incurred a debt of gratitude to SPSL Secretary Miss Liz Fraser.
For her research in the British Library, I am grateful to Katherine Prior.
Other archivists and archives whose help was invaluable are: Colin Harris, Bodleian Library, Oxford. Richard Popp and Daniel Meyer, Special Collections Research Center, University of Chicago Library. Dirk Ullmann and many other archivists at the Archiv der Max-Planck-Gesellschaft (AMPG), Berlin. Landesarchiv, Berlin.
For permission to quote from the unpublished writings of Leo Szilard, I am grateful to Egon Weiss.
For translations, I am grateful to Edith Baltram, Alfred Haunold, Julie Meyer, and AzeemKhan Mondokhail.
For assisting my search for documents and memories of Gerda at the Ben Shemen Youth Village, I thank Meir and Hagit Gal-Ed, Yael and Shim Leigh, Stella Padeh, and Uri Yaloz.
For their help in my unsuccessful attempt to trace Anita Kashyap, I am grateful to Anita and Ashish Kashyap, Navras Jaat Aafreedi, and Ralphy Jhirad.
For correspondence about the lack of documentary source material about Gerda in Germany, I acknowledge Joachim Oesterheld.
For reading the text of this manuscript, I am grateful to P.D. Smith. All errors are my own.
 Author interviews with Bela Silard at his home in Pleasantville, New York, June 23 and 24, 1982. Longer quotation from Bela Silard to the author, February 24, 1983.
 William Lanouette with Bela Silard, Genius in the Shadows: A Biography of Leo Szilard, the Man Behind the Bomb (New York: Scribner’s, 1992).
 Apartment at 95 Prinzregentenstrasse. Polizeiliche Abmeldung, October 1, 1927, Leo Szilard Papers, Box 1 folder 26, Special Collections and Archives, U.C.S.D.. Lanouette states on pages 72 and 500 (note 8) that Szilard lived with Gerda Philipsborn’s widowed mother on Geisbergstrasse beginning in the fall of 1924, and moved with them thereafter. However, Gerda’s mother wasn’t a widow, and the Philipsborns had been living on Prinzregentenstrasse since 1917. Szilard’s Berlin police residence registration forms in the Szilard Papers are a complete sequence, and show no landlords named Philipsborn before October 1, 1927. The Berliner Adressbuch for all those years is available online at http://www.zlb.de/besondere-angebote/berliner-adressbuecher.html. Most of Lanouette’s information about Gerda is incorrect.
 Eximia notation. Doctoral Diploma, August 14, 1922, Leo Szilard Papers Box 1 folder 24, Oversize FB-129-11, Special Collections and Archives, University of California, San Diego.
 For the story of the refrigerators, see Gene Dannen, “The Einstein-Szilard Refrigerators,” Scientific American, January 1997.
 Jacob and Ida dates of birth from their death and burial records, Landesarchiv, Berlin.
 Savings wiped out by inflation. Author telephone interviews with Gerry Brent, November 22, 1999 and January 23, 2000.
 Ida died of pneumonia. Death and burial records, Landesarchiv, Berlin.
 Death and burial records for Ida Mond Philipsborn, Landesarchiv, Berlin.
 Gerda’s date and place of birth. British citizenship application, May 26, 1937, OIOC records, L/P&J/7/2093, British Library.
 Philipsborn children dates of birth. Artur: Death Certificate, Oakland California, County of Alameda, State File Number 73-014066, local registration district 6015, local certificate number 1897. Lizzie: Volkszählung 1938, Berlin, Ergänzungskarte für Angaben über Abstammung und Vorbildung (Potsdam: Bundesarchiv, 1991). Claire: Michael Hepp, Die Ausbürgerung deutscher Staatsangehöriger 1933-45 nach den im Reichsanzeiger veröffentlichten Listen (München, New York: Saur, 1985-88).
 Jacob born in Bentschen. Death and burial records, Landesarchiv, Berlin.
 Ida born into Mond family in Cassel. Death and burial records, Landesarchiv, Berlin. Author telephone interviews with Gerry Brent November 22, 1999 and January 23, 2000. Gerda’s family tree courtesy Gerry Brent.
 Ludwig Mond was Ida’s cousin. Same sources as previous reference.
 Author telephone interviews with Gerry Brent, November 22, 1999, January 23, 2000. Gerry Brent to the author, December 14, 1999. Gerry changed his name from Berendt to Brent at the request of the British military during service in WWII.
 Artur medical degree and military service. American Medical Directory, American Medical Association, 1956 p. 1599. Author telephone interviews with Gerry Brent, November 22, 1999 and January 23, 2000, Gerry Brent to the author, December 14, 1999.
 Munich and Bruno Walter. Anita Kashyap, “Gerda Philipsborn,” (obituary), Jewish Advocate (Bombay), May 1943, courtesy Gerry Brent. M. Mujeeb, “Aapa Jaan, Miss Gerda Philipsborn,” (in Urdu), Jauhar, Jamia Jubilee issue (1946), translated for the author by AzeemKhan Mondokhail. B. Sheik Ali, Zakir Husain: Life and Times (New Delhi: Vikas Publishing House, 1991) p. 94. Multiple sources stated that Gerda studied music at an academy in Munich, but I was unable to verify this. Susanne Frintrop, Leiterin der Bibliothek, Musikhochschule-München, email to the author, July 15, 2004. Almost no written records about Gerda seem to have survived in Germany.
 Gerda’s opera success. Anita Kashyap, “Gerda Philipsborn”, obituary, May 1943, Jewish Advocate (Bombay), courtesy Gerry Brent.
 Sold patent to Electrolux. Gene Dannen, “The Einstein-Szilard Refrigerators,” Scientific American, January 1997.
 Ellen Berger’s description of Philipsborn apartment. Author telephone interview with Ellen Berger, February 13, 2000.
 “Too many things to do in life.” Nicholas and Robert Halász, “Leo Szilárd, the Reluctant Father of the Atom Bomb,” The New Hungarian Quarterly, Volume XV No. 55 Autumn 1974, pp. 163-173, quoted p. 173.
 Favorite of Bruno Walter, who unfailingly sent tickets. A.G. Noorani, President Zakir Husain: A Quest for Excellence (Bombay: Popular Prakashan, 1967) p. 23.
 Siegfried Lehmann and Volksheim. Anita Kashyap, “Gerda Philipsborn,” (obituary), Jewish Advocate (Bombay) May 1943, courtesy Gerry Brent. For background on Siegfried Lehmann, the Volksheim, and Ben Shemen, I have consulted the following works, none of which mention Gerda: Norman Bentwich, Ben-Shemen: A Children’s Village in Israel (Jerusalem: Jerusalem Post Press, 1959). Maurice Friedman, Martin Buber’s Life and Work: the Early Years 1878-1923 (New York: Dutton, 1981) p. 277 and The Middle Years 1923-1945 (New York: Dutton, 1983) pp. 6-7. Franz Kafka, Letters to Felice (New York: Schocken Books, 1973). Kathi Diamant, Kafka’s Last Love: The Mystery of Dora Diamant (New York: Basic Books, 2003). Steven E. Aschheim, Brothers and Strangers (Madison Wisconsin: University of Wisconsin Press, 1982). Ari Shavit, “Lydda, 1948,” New Yorker, October 21, 2013. “Jewish People’s Home - Jüdisches Museum Berlin,” online at http://www.jmberlin.de/berlin-transit/en/orte/juedischesvolksheim.php
 Gerda seen transporting donated items. A.G. Noorani, President Zakir Husain: A Quest for Excellence (Bombay: Popular Prakashan, 1967) p. 23. M. Mujeeb, “Aapa Jaan, Miss Gerda Philipsborn,” (in Urdu) Jauhar, Jamia Jubilee issue (1946), translated for the author by AzeemKhan Mondokhail.
 Ben Shemen Youth Village. Author interviews with Gerry Brent, November 22, 1999 and January 23, 2000. Anita Kashyap, “Gerda Philipsborn,” (obituary), Jewish Advocate (Bombay), May 1943, courtesy Gerry Brent.
 Electron microscope. Dennis Gabor, preface to L. Marton, Early History of the Electron Microscope (San Francisco: San Francisco Press, 1968), p vi. Gabor, “History of the electron microscope, from ideas to achievements,” Eighth International Congress on Electron Microscopy, Canberra 1974 vol 1 pp. 6-12. Gabor, “Die Entwicklungsgeschichte des Elektronenmikroskops,” Elektrotechnische Zeitschrift A, 15 Heft, 78 Jahrgang, 1 August 1957, pp. 522-530. I am grateful to Ernst Ruska for drawing my attention to the ETZ article. (Ernst Ruska to the author, November 11, 1987.) Szilard did not agree with Gabor’s negative assessment, as it is stated he did in Genius in the Shadows p. 94. I have changed the word order of one word of Gabor’s reply to improve readability. For the original word order, see the text of my talk at the 1998 Szilard Centenary in Budapest, “Leo Szilard the Inventor,” online at http://www.dannen.com/budatalk.html
Update added June 22, 2015: After publication, William Lanouette insisted to me that I was mistaken and his version was correct, citing T.E. Allibone, “The Life and Work of Dennis Gabor: His Contributions to Cybernetics, Philosophy and the Social Sciences 1900-1979,” The Dennis Gabor Memorial Lecture Given to the Cybernetics Society on the 23rd of April 1985.
However, that account is based on T.E. Allibone, “Dennis Gabor, 5 June 1900 — 9 February 1979,” Biographical Memoirs of the Fellows of the Royal Society, 1980, 26, 1 November 1980, pp. 106-147, where Allibone identifies his source (see p. 133) as J.B. le Poole, “Erepromotie prof. D. Gabor, D.Sc. — Considerans, uitgesproken door prof. dr. ir. J.B. le Poole, Technische Hogeschool Delft,” De Ingenieur 83 (5), 5 Februari 1971, pp. A80-81.
This is what le Poole said: “As a proof of your fairness and honesty I repeat a little anecdote you once told me yourself: you were walking in the streets of Berlin with your friend Szillard [sic] and discussing the wave nature of electrons just published by de Broglie. Summing up, you both agreed that here was an ultra short wave radiation, readily available with lenses to go with it. So why not build an electron microscope? But you both agreed that it would serve no purpose! And so you missed that one.”
I cited three separate articles by Gabor where he told the story himself, very differently from le Poole, and he most certainly did not say that Szilard agreed with him. Compared to those first-person accounts, le Poole’s recollection of what Gabor “once told him” is not credible. Moreover, I would emphasize Gabor’s comment (in the Canberra volume I cited above) that, “If I know Szilard, he probably put the same suggestion to other experimenters, and probably got the same answer from them.” Obviously, Szilard would not have made the same suggestion to others if he agreed with Gabor that an electron microscope would serve no purpose. I apologize for belaboring this point, but I consider it important for the history of science.
 Taught seminar with von Neumann. University of Berlin class listings, as published in Universität Berlin Vorlesungsverzeichnis (copies courtesy Frank Unger) and issues of Physikalische Zeitschrift.
 Attend finest cultural events. M. Mujeeb, Dr. Zakir Husain (New Delhi: National Book Trust India, 1972) pp. 36-37. B. Sheik Ali, Zakir Husain: Life and Times (New Delhi: Vikas Publishing House, 1991) p. 93.
 Einstein-Szilard refrigerator at A.E.G.. Gene Dannen, “The Einstein-Szilard Refrigerators,” Scientific American, January 1997.
 Gerda trip to London. Purpose of trip from Anita Kashyap, “Gerda Philipsborn,” (obituary), Jewish Advocate (Bombay) May 1943, courtesy Gerry Brent. Gerda was in London on her first fundraising trip from November 21, 1928 to July 1929. Source: British citizenship application, May 26, 1937, OIOC records, L/P&J/7/2093, British Library.
 Gerda’s Mond relatives. Eva Violet Mond Isaacs, For the Record: The Memoirs of Eva, the Marchioness of Reading (London: Hutchinson & Co., 1973). Jean Goodman, The Mond Legacy: A Family Saga (London: Weidenfeld and Nicolson, 1982). J.M. Cohen, The Life of Ludwig Mond (London: Methuen & Co., 1956). Hector Bolitho, Alfred Mond: First Lord Melchett (New York: D. Appleton and Company, 1933). None of these books mention Gerda or her family.
 Linear accelerator and cyclotron patent applications. Reprinted in Bernard T. Feld and Gertrud Weiss Szilard (eds.) The Collected Works of Leo Szilard: Scientific Papers (Cambridge MA: MIT Press, 1972) pp. 543-563.
 Einstein’s Electro Chemical Process Limited. Large paid advertisement for forthcoming offering of public shares, London Times, January 17, 1929 p. 18.
 Gerda Philipsborn to Einstein, February 3, 1929. EA #46-094, Albert Einstein Archives, Hebrew University of Jerusalem.
 Visited Gerda at boarding house. Return address on Szilard to Michael Polanyi, April 1, 1929, Michael Polanyi Papers, Box 2 folder 5, Special Collections Research Center, University of Chicago Library. See also Szilard to Einstein, April 2, 1929, EA #21-433, Einstein Archives, Hebrew University of Jerusalem. Boarding house: Sue McKenzie and Jon Newman, Lambeth Archives Department, London, to the author, December 12, 1998.
 Dinner with Wells. Szilard to Michael Polanyi, April 1, 1929, Michael Polanyi Papers, Box 2 folder 5, Special Collections Research Center, University of Chicago Library.
 H.G. Wells, The Open Conspiracy: Blue Prints for a World Revolution. (London: V. Gollancz, 1928.)
 Gerda was in London on her second fundraising trip from October 30, 1929 to July 23, 1930. Source: British citizenship application, May 26, 1937, OIOC records, L/P&J/7/2093, British Library. Purpose of trip from Anita Kashyap, “Gerda Philipsborn,” (obituary), Jewish Advocate (Bombay) May 1943, courtesy Gerry Brent.
 Visited Gerda again in London in 1930. See also Szilard to Einstein March 22, 1930 EA #35-586, Szilard to Einstein March 22, 1930 EA #21-434, Szilard to Einstein April 1, 1930 EA #35-588, Einstein Archives, Hebrew University of Jerusalem. Einstein to Brailsford, April 24, 1930, quoted in Otto Nathan and Heinz Norden (eds.), Einstein on Peace (New York: Avenel Books, 1981) pp. 103-104. Einstein’s thinking was closer to Szilard’s than this letter makes it appear. Draft proposal for the Bund in Weart and Szilard (eds.) Leo Szilard: His Version of the Facts pp. 22-30.
 Szilard’s Bund. Draft proposal for the Bund in Leo Szilard: His Version of the Facts pp. 22-30. Szilard later recalled that his plans for the Bund drew in part on the history of the Jugendbewegung, the German Youth Movement (His Version p. 22). This has remained mysterious, since Szilard was never a member of such an organization. However, it might be explained by Gerda’s friendship with Wilfrid Israel, a wealthy social activist whose family owned a Berlin department store. Israel’s enthusiasm about the movement is mentioned in Naomi Shepherd, A Refuge from Darkness: Wilfrid Israel and the Rescue of the Jews (New York: Pantheon Books, 1984).
 Szilard to Einstein, September 27, 1930. Quoted in Gene Dannen, “The Einstein-Szilard Refrigerators,” Scientific American, January 1997.
 Seminars with Schrödinger, von Neumann, and Meitner. University of Berlin class listings as published in Universität Berlin Vorlesungsverzeichnis (copies courtesy Frank Unger), and issues of Physikalische Zeitschrift.
 Max Knoll public lecture. Ernst Ruska, The Early Development of Electron Lenses and Electron Microscopy (Stuttgart: S. Herzel Verlag, 1980) pp 26-28.
 Electron microscope patent application. Feld and Szilard (eds.) The Collected Works of Leo Szilard: Scientific Papers p. 707. Szilard’s passport shows that he visited Salzburg, Austria later that summer on August 23, 1931 during the Salzburger Festspiele. It seems possible that he attended music performances there with Gerda. Passports, Leo Szilard Papers Box 1 folder 7, Special Collections and Archives, U.C.S.D..
 Princeton job offer. L.P. Eisenhart to Szilard, September 24, 1931, Leo Szilard Papers Box 15 folder 24, Special Collections and Archives, U.C.S.D..
 Szilard to Einstein October 19, 1931 with postscript by Gerda Philipsborn, EA# 21-439, Einstein Archives, Hebrew University of Jerusalem.
 Quantum theory did not offer him enough. Eugene Wigner, The Recollections of Eugene P. Wigner as told to Andrew Szanton (New York: Plenum Press, 1992) p. 98. Wigner’s recollections must be treated with great caution because he was suffering from Alzheimer’s Disease. One would never guess, reading this book, that Szilard was once his dearest friend.
 Scientists’ pledge of non-cooperation with Japan. Weart and Szilard (eds.) Leo Szilard: His Version of the Facts pp. 36-38.
 Refrigerator work ended. Gene Dannen, “The Einstein-Szilard Refrigerators,” Scientific American, January 1997.
 Inspired by Gandhi. A.G Noorani, President Zakir Husain: A Quest for Excellence (Bombay: Popular Prakashan, 1967) p. 23. S.R. Sharma, Life and Works of Zakir Husain (Jaipur: Book Enclave, 2006) p. 19.
 Met Zakir Husain. M. Mujeeb, Dr. Zakir Husain (New Delhi: National Book Trust India, 1972) pp. 36-37.
 Founding of Jamia. M. Mujeeb, Dr. Zakir Husain pp. 24-28.
 Gandhi provided Jamia funding. M. Mujeeb in Radhey Mohan (ed.) Dr. Zakir Husain as I Saw Him (New Delhi: Indiana Publications, 1974) p. 68. M. Mujeeb, “Dr. Zakir Husain and the Jamia Millia Islamia,” in V.S. Mathur (ed.) Zakir Husain: Educationist and Teacher, (New Delhi: Arya Book Depot, 1969) p. 38.
 Warned not to come to Jamia. M. Mujeeb, Dr. Zakir Husain p. 54. B. Sheik Ali, Zakir Husain: Life and Times (New Delhi: Vikas Publishing House, 1991) p. 158.
 Gerda left for Ben Shemen on way to India. Destinations from Anita Kashyap, “Gerda Philipsborn,” (obituary) Jewish Advocate (Bombay) May 1943, courtesy Gerry Brent. Date from Gerda’s British citizenship application, May 26, 1937, OIOC records, L/P&J/7/2093, British Library.
 Szilard to Wigner, October 8, 1932. Leo Szilard Papers Box 21 folder 4, Special Collections and Archives, UCSD. Translation by Julie Meyer, Gene Dannen.
 Checked into Harnack Haus. Harnack House records, Archiv der Max-Planck-Gesellschaft (AMPG), Abt. l, Rep. 1A, No. 2513.
 Taught no classes. “Memoirs — Leo Szilard,” Leo Szilard Papers Box 40 folder 10, Special Collections and Archives, U.C.S.D..
 Arrival date in Bombay from British citizenship application, May 26, 1937, OIOC records, L/P&J/7/2093, British Library.
 Hired to Jamia staff. M. Mujeeb, Dr. Zakir Husain p.54.
 Liebowitzes in Berlin. Author telephone interviews with Ellen Berger (February 13, 2000) and Renate Strauss (February 10 and February 21, 2000). Liebowitz to Ernst Boas (postcard) November 2, 1932, reproduced in Norman F. Boas, “The loan which helped change the fate of the world,” Manuscripts, Volume XLX Number 1, Winter 1998, p. 17. (The image of the postcard is reliable, but the rest of the article is inaccurate.) Liebowitz to Ernst Boas, May 4, 1933, Leo Szilard Papers Box 12 folder 4, Special Collections and Archives, U.C.S.D.. Joseph Hutchison, “Elsbeth Liebowitz: a Life in Brief,” online at http://www.jhwriter.com/Docs/ALifeInBrief.pdf
 Trip home to Budapest. Passports, Box 1 folder 7, Leo Szilard Papers, Special Collections and Archives, U.C.S.D.. Harnack House records, Archiv der Max-Planck-Gesellschaft (AMPG), Abt. l, Rep. 1A, No. 2513.
 Polanyi decided to stay in Berlin. Weart and Szilard (eds.) Leo Szilard: His Version of the Facts, p. 14. See also Mary Jo Nye, Michael Polanyi and His Generation (Chicago: University of Chicago Press, 2011), pp. 72-76.
 Safety in Denmark. Author telephone interviews with Ellen Berger and Renate Strauss.
 Train to Vienna March 31. Passports, Box 1 folder 7, Leo Szilard Papers, Special Collections and Archives, U.C.S.D.. Szilard checked out of the Harnack Haus on March 30. Archiv der Max-Planck-Gesellschaft (AMPG), Abt. l, Rep. 1A, No, 2513.
 Train passengers interrogated. Weart and Szilard (eds.) Leo Szilard: His Version of the Facts, p. 14.
 Description of Jamia conditions. M. Mujeeb, Dr. Zakir Husain, p. 51.
 “This is your Aapa Jaan...” Obaidul Haq, “In the Student’s Eyes,” in Syeda Saiyidain Hameed (ed.) Zakir Husain: Teacher Who Became President (Delhi: Har Anand Publications, 2000), quoted p. 249.
 As if she were their own mother. Sughra Mehdi, Bachchon ki AapaJaan. Unpublished English translation from the Urdu by M.T. Qureshi, courtesy Tabish Qureshi.
 Interviews with Obaidul Haq and Shoebur Rehman by M. Zahid, early May 2000, and again with Haq, July 2004. Zahid reported that, even almost 70 years after those events, their eyes sparkled with enthusiasm at the memories (Tabish Qureshi email to the author, May 22, 2000).
 Worked with Academic Assistance Council. For information on Szilard’s work with the Council, see R.M. Cooper (ed.) Refugee Scholars: Conversations with Tess Simpson (Leeds: Moorland Books, 1992), especially Appendix A. See also Shula Marks, Paul Weindling, and Laura Wintour (eds.) In Defence of Learning: The Plight, Persecution, and Placement of Academic Refugees, 1933-1980s, (Oxford: Oxford University Press, 2011). For archival sources, see SPSL files, Bodleian Library, Oxford.
 Szilard’s letter to Gerda. Szilard to “addressee unknown,” August 11, 1933, reprinted in Leo Szilard: His Version of the Facts, pp. 34-36
 Rutherford speech. London Times, September 12, 1933 p. 7. Lanouette states on page 132 of Genius in the Shadows that Szilard planned to attend Rutherford’s talk, but was prevented by a bad cold. This is contradicted by Szilard’s multiple accounts of the event, and Lanouette has been unable to provide any source. I believe that the “bad cold” story is simply erroneous.
Update added June 22, 2015: After publication, Lanouette reported to me that he had discovered that his source was Bela Silard. However, I do not consider Bela to be a reliable source on this subject. It seems much more likely that Bela was thinking of the bad cold Szilard suffered after learning of the discovery of fission.
 Moment of conception of chain reaction. Weart and Szilard (eds.), Leo Szilard: His Version of the Facts, p. 17.
 H.G. Wells, The World Set Free: A Story of Mankind (London: McMillan, 1914).
 India jobs through Academic Assistance Council. Bangalore: Handwritten note by unidentified AAC staffer, “Papers re Szilard (sent to me for Bangalore application),” December 12, 1933, MSS.SPSL.342/2, SPSL files, Bodeleian Library, Oxford. Tutor: Unidentified A.A.C. staffer to Szilard, November 6, 1933 and related handwritten note headed “Miss Williams.” MSS.SPSL.167/2, SPSL files, Bodleian Library, Oxford. SPSL archive material has been reproduced by kind permission of CARA (the Council for At-Risk Academics).
 Job opening in Delhi. Szilard to P. Gent, A.A.C., January 9,1934, MSS.SPSL.342/2, SPSL files, Bodleian Library, Oxford. SPSL archive material has been reproduced by kind permission of CARA (the Council for At-Risk Academics).
 Szilard to Michael Polanyi, January 29, 1934, Michael Polanyi Papers, Box 2 folder 14, Special Collections Research Center, University of Chicago Library.
 British patent application 7840/34. The resulting patent is reprinted in Feld and Szilard (eds.) The Collected Works of Leo Szilard: Scientific Papers pp. 622-631.
 Met with Rutherford. Walter Adams to Rutherford, May 29, 1934; Rutherford to Adams, May 30, 1934; Adams to Rutherford, May 31, 1934; Adams to Szilard, May 31, 1934; Adams to Rutherford, May 31, 1934; MSS.SPSL.342/2, SPSL files, Bodleian Library, Oxford, reproduced by kind permission of CARA (the Council for At-risk Academics). “Surely I have explained...” Rutherford quoted in Mark Oliphant, Rutherford: Recollections of the Cambridge Days (Amsterdam: Elsevier, 1972) p. 141 (emphasis and punctuation added).
 Money orders to Delhi. “Certificate of Issue of a Money Order,” June 16 and 26, 1934, Szilard Papers Box 1 folder 25. The name of the recipient is not listed, but the obvious conclusion is that it was Gerda. Value comparison calculated using room rates for the Strand Palace Hotel from the 1930 edition of Baedeker’s London and Its Environs, and taking into account that Szilard’s room was cheaper than average.
 I.C.I. refugee fellowship. For a published source, see page 258 of Jack Morrell, “The Lindemann Era,” in Robert Fox and Graeme Gooday (eds.) Physics in Oxford 1839-1939 (Oxford: Oxford University Press, 2005).
 Met Trude Weiss January 1930. Gertrud Weiss Szilard to Spencer Weart, September 17, 1975, Leo Szilard Papers Box 88 folder 17. Gertrud Weiss Szilard interviewed by Harold Keen, October 12, 1980, Leo Szilard Papers Box 101 folder 7, Special Collections and Archives, U.C.S.D..
 Szilard to Trude Weiss, March 26, 1936, Leo Szilard Papers, Box 20 folder 9, Special Collections and Archives, U.C.S.D.. Tristram Coffin, “Leo Szilard: the Conscience of a Scientist,” Holiday, February 1964 p 96.
 British War Office. J. Coombes, Director of Artillery, to Claremont Haynes & Co., October 8, 1935, Leo Szilard Papers Box 20 folder 9, Special Collections and Archives, U.C.S.D..
 British Admiralty. Director of Navy Contracts to Szilard, March 20, 1936, Leo Szilard Papers Box 4 folder 2, Special Collections and Archives, U.C.S.D.. Patent reprinted in Feld and Szilard (eds.) The Collected Works of Leo Szilard: Scientific Papers pp. 639 to 651.
 Tried to convince colleagues. Szilard to Fermi, March 13, 1936, reprinted in Feld and Szilard (eds.) The Collected Works of Leo Szilard: Scientific Papers pp. 729-730. Szilard to Segre, March 30, 1936, Leo Szilard Papers Box 17 folder 18, Special Collections and Archives, U.C.S.D.. Szilard to Segre, April 1, 1936, reprinted in The Collected Works of Leo Szilard Scientific Papers pp. 731-732. Szilard to Rutherford, May 27, 1936 and Szilard to Cockroft, May 27, 1936, reprinted in Weart and Szilard (eds.) Leo Szilard: His Version of the Facts pp. 45-48.
 Giannini to Fermi, March 17, 1936, quoted in Simone Turchetti, “The Invisible Businessman: Nuclear physics, patenting practices, and trading activities in the 1930s,” Historical Studies in the Physical and Biological Sciences, Volume 37, Part 1 (2006) p. 168.
 Death of Jacob Philipsborn. Author telephone interviews with Gerry Brent. Date from death and burial records, Landesarchiv, Berlin.
 Gerda’s application for British citizenship, May 26, 1937, OIOC records L/P&J/7/2093, British Library.
 Report by Superintendent of Police, Criminal Investigation Department, Delhi, June 16-17, 1937, same file. Also in the file, note the praise of Gerda by Otto Schiff of the German Jewish Relief Committee.
 Clare was a firebrand. Author interviews with Gerry Brent. Gerry Brent believed that Claire died in the Spanish conflict. Renate Strauss, however, told me that she survived and went to Lima, Peru, where she later died. She recalled that Claire’s last letter to her parents from Lima said, “Be sure to bring up your children as good communists.” Author telephone interview with Renate Strauss, February 10, 2000. Claire’s presence in the Spanish Civil War is also mentioned (as Clara Philipsborn) in Thomas Pusch, “Spanien’s Himmel...” online at: http://www.akens.org/akens/texte/info/32/17
 “Coming for your son’s passport.” Author interviews with Gerry Brent.
 NOW OR NEVER. Author interviews with Bela Silard, June 23 and 24, 1982.
 “The Liebowitzes saved our lives.” Author telephone interview with Renate Strauss, February 10, 2000. Date of arrival from ship passenger lists, accessed through Ancestry.com.
 Paid by Ludwig Mond’s brother-in-law. Author interviews with Gerry Brent. For Gerry Brent’s parents, it was indeed the last minute. Ship passenger records show that they sailed from Southampton bound for Australia on August 4, 1939. Passenger list accessed through Ancestry.com.
 For the story of the Einstein letter to Roosevelt, see Gene Dannen, “Einstein to Roosevelt, August 2, 1939,” online at http://www.dannen.com/ae-fdr.html
 Gerda letters to Lady Reading, OIOC records, L/P&J/8/68 (part 6), British Library.
 Ill before the start of the war. Anita Kashyap, “Gerda Philipsborn” (obituary), Jewish Advocate (Bombay) May 1943, courtesy Gerry Brent. Anonymous letter to editor, Jewish Advocate (Bombay), June 1943, courtesy Gerry Brent.
 Release from Purandhar. “Decypher of Telegram from Government of India, Home Department, to Secretary of State for India,” September 25, 1941, OIOC records, L/P&J/8/66, f. 75, British Library.
 Draft order for Szilard’s internment. Secretary of War to Attorney General (written by Groves), October 28, 1942, RG 77, M.E.D. Files, 201 Szilard Leo, U.S. National Archives. Testimony of General Leslie R. Groves, In the Matter of J. Robert Oppenheimer (Washington D.C: Government Printing Office, 1954) , p 172.
 Shook hands with Fermi quotation. Weart and Szilard (eds.) Leo Szilard: His Version of the Facts, p. 146.
 Celebrations on her return. Abdul Ghaffar Mudholi, Jamia ki Kahani (New Delhi: Maktaba Jamia, 1965), information and reference from Tabish Qureshi email to the author, May 21, 2000.
 Advised Husain on education policy. B. Sheik Ali, Zakir Husain: Life and Times (Delhi: Vikas Publishing House, 1991) p. 153.
 Jamia Life Member. Online at http://jmi.ac.in/aboutjamia/profile/history/life-members-18
 Severe pains in her stomach. M. Mujeeb Dr. Zakir Husain p. 55.
 Zakir Husain book dedication. Zakir Husain, Talimi Khutbat (Delhi: Maktaba Jamia, 1943). Though the book states a publication date of 1942, it was not actually published until 1943. I have verified the date of the dedication. Translation of dedication quoted in full in Syeda Saiyidain Hameed (ed.), Zakir Husain: Teacher Who Became President (Delhi: Har Anand Publications, 2000) p 417. Translation of title from A.G. Noorani, President Zakir Husain: A Quest for Excellence (Bombay: Popular Prakashan, 1967) p. 62.
 Cancer surgery. A.G. Noorani, President Zakir Husain: A Quest for Excellence p 62.
 Gerda died April 14, 1943. Date from M. Mujeeb “Aapa Jaan, Miss Gerda Philipsborn” (in Urdu) Jauhar, Jamia Jubilee Number, 1946, translated for the author by AzeemKhan Mondokhail. Also K.A. Hamied, A Life to Remember: An Autobiography (Bombay: Lalvani Publishing House, 1972) p. 37. Age from date of birth in Gerda’s British citizenship application, OIOC records, L/P&J/7/2093, British Library.
 Cleverest... most kindhearted woman. “Gerda Philipsborn,” anonymous letter to editor from “A former co-internee,” Jewish Advocate (Bombay), June 1943, courtesy Gerry Brent.
 Most perfect friend has gone forever. Anita Kashyap, “Gerda Philipsborn,” (obituary) Jewish Advocate (Bombay), May 1943, courtesy Gerry Brent.
 Franck Report, June 11, 1945. Full text online at http://www.dannen.com/decision/franck.html
 Leo Szilard, “A Petition to the President of the United States,” July 17, 1945. Full text including names of signers online at http://www.dannen.com/decision/45-07-17.html
 Married Trude Weiss. Marriage Certificate, Leo Szilard Papers Box 1 folder 5, Special Collections and Archives, U.C.S.D.
 “Close-Up: ‘I’m Looking for a Market for Wisdom,’ Leo Szilard, scientist,” Life Magazine, September 1, 1961, pp. 75-79. “Are We on the Road to War?” see Gene Dannen, “Are We On the Road to War? Leo Szilard and the Council for a Livable World,” online at http://www.dannen.com/roadtowar.html
 M. Mujeeb, Dr. Zakir Husain, (New Delhi: National Book Trust, India, 1972).
 M. Mujeeb, “Aapa Jaan, Miss Gerda Philipsborn,” (in Urdu) Jauhar, Jamia Jubilee number, 1946. Translation from the Urdu for the author by AzeemKhan Mondokhail.
 Sughra Mehdi, Bachchon ki AapaJaan. (New Delhi: Maktaba Payam-e Taleem, 1996?). Unpublished English translation by M.T. Qureshi, courtesy Tabish Qureshi. The Jamia library also holds a short children’s book that Gerda wrote, titled (in Urdu) Children’s Zoo. (New Delhi: Payame Taleem, Jamia Millia Islamia). It is a picture book of designs for making folded paper animals. Photocopy courtesy M. Zahid.
 “Gerda Philipsborn Day Care Centre for Jamia Students and Staff,” by R. Nithya, Jamia Journal, October 5, 2013, jamiajournal.com. For a story on the appearance of Gerda’s grave today, see “Here Lies Gerda Philipsborn, Buried and Forgotten,” (editorial), by Khalid Jaleel, Jamia Journal, August 22, 2014, jamiajournal.com.
 Inscription on back of “Early Childhood. Group Photo,” Leo Szilard Papers Box 100 folder 9, Special Collections and Archives, U.C.S.D..
 Translation of inscription by Alfred Haunold, Gene Dannen.
 “Early Childhood. Group Photo.” Leo Szilard Papers, Box 100 folder 9, Special Collections and Archives, U.C.S.D.