Leo Szilard

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The native form of this personal name is Szilárd Leó. This article uses Western name order when mentioning individuals.

Leo Szilard
Humboldt University
Known for
See list
  • Einstein–Szilard refrigerator
Awards
  • Salk Institute
Thesis Über die thermodynamischen Schwankungs­erscheinungen  (1923)
Doctoral advisorMax von Laue
Other academic advisorsAlbert Einstein
Signature

Leo Szilard (

atomic bomb. According to György Marx, he was one of the Hungarian scientists known as The Martians.[1]

Together with

feedback inhibition and the invention of the chemostat. According to Theodore Puck and Philip I. Marcus
, Szilard gave essential advice which made the earliest cloning of the human cell a reality.

Szilard initially attended

philosophy of thermal and statistical physics. Szilard was the first scientist of note to recognize the connection between thermodynamics and information theory
.

After

Szilard petition advocating a demonstration of the atomic bomb, but the Interim Committee chose to use them against cities
without warning.

He publicly sounded the alarm against the possible development of salted thermonuclear bombs, a new kind of nuclear weapon that might annihilate mankind. Diagnosed with bladder cancer in 1960, he underwent a cobalt-60 treatment that he had designed. He helped found the Salk Institute for Biological Studies, where he became a resident fellow. Szilard founded Council for a Livable World in 1962 to deliver "the sweet voice of reason" about nuclear weapons to Congress, the White House, and the American public. He died in his sleep of a heart attack in 1964.

Early life

He was born as Leó Spitz in

agnostic.[4][5] From 1908 to 1916 he attended the Lutheran gymnasium school in his home town along with others such as Edward Teller.[6] Showing an early interest in physics and a proficiency in mathematics, in 1916 he won the Eötvös Prize, a national prize for mathematics.[7][8]

Leo Szilard in 1915[9]

With World War I raging in Europe, Szilard received notice on January 22, 1916, that he had been drafted into the 5th Fortress Regiment, but he was able to continue his studies. He enrolled as an engineering student at the

Spanish Influenza and was returned home for hospitalization.[10] Later he was informed that his regiment had been nearly annihilated in battle, so the illness probably saved his life.[11] He was discharged honorably in November 1918, after the Armistice.[12]

In January 1919, Szilard resumed his engineering studies, but Hungary was in a chaotic political situation with the rise of the Hungarian Soviet Republic under Béla Kun. Szilard and his brother Béla founded their own political group, the Hungarian Association of Socialist Students, with a platform based on a scheme of Szilard's for taxation reform. He was convinced that socialism was the answer to Hungary's post-war problems, but not that of Kun's Hungarian Socialist Party, which had close ties to the Soviet Union.[13] When Kun's government tottered, the brothers officially changed their religion from "Israelite" to "Calvinist", but when they attempted to re-enroll in what was now the Budapest University of Technology, they were prevented from doing so by nationalist students because they were Jews.[14]

Time in Berlin

Convinced that there was no future for him in Hungary, Szilard left for

Walter Nernst, James Franck and Max von Laue.[16] He also met fellow Hungarian students Eugene Wigner, John von Neumann and Dennis Gabor.[17]

Szilard's doctoral

philosophy of thermal and statistical physics known as Maxwell's demon, a thought experiment originated by the physicist James Clerk Maxwell. The problem was thought to be insoluble, but in tackling it Szilard recognized the connection between thermodynamics and information theory.[18][19]
Szilard was appointed as assistant to von Laue at the Institute for Theoretical Physics in 1924. In 1927 he finished his
John Von Neumann pointed out that Szilard first equated information with entropy in his review of Wiener's Cybernetics book.[22][23]

Throughout his time in Berlin, Szilard worked on numerous technical inventions. In 1928 he submitted a

scientific journals, and so credit for them often went to others. As a result, Szilard never received the Nobel Prize, but Ernest Lawrence was awarded it for the cyclotron in 1939, and Ernst Ruska for the electron microscope in 1986.[28]

An image from the Fermi–Szilard "neutronic reactor" patent

Szilard received German citizenship in 1930, but was already uneasy about the political situation in Europe.

Academic Assistance Council, an organization dedicated to helping refugee scholars find new jobs, and persuaded the Royal Society to provide accommodation for it at Burlington House. He enlisted the help of academics such as Harald Bohr, G. H. Hardy, Archibald Hill and Frederick G. Donnan. By the outbreak of World War II in 1939, it had helped to find places for over 2,500 refugee scholars.[32]

Nuclear physics

On the morning of September 12, 1933, Szilard read an article in

Lord Rutherford in which Rutherford rejected the feasibility of using atomic energy for practical purposes. The speech remarked specifically on the recent 1932 work of his students, John Cockcroft and Ernest Walton, in "splitting" lithium into alpha particles, by bombardment with protons from a particle accelerator they had constructed.[33]
Rutherford went on to say:

We might in these processes obtain very much more energy than the proton supplied, but on the average we could not expect to obtain energy in this way. It was a very poor and inefficient way of producing energy, and anyone who looked for a source of power in the transformation of the atoms was talking moonshine. But the subject was scientifically interesting because it gave insight into the atoms.[34]

Szilard was so annoyed at Rutherford's dismissal that, on the same day, he conceived of the idea of nuclear chain reaction (analogous to a chemical chain reaction), using recently discovered neutrons. The idea did not use the mechanism of nuclear fission, which was not yet discovered, but Szilard realized that if neutrons could initiate any sort of energy-producing nuclear reaction, such as the one that had occurred in lithium, and could be produced themselves by the same reaction, energy might be obtained with little input, since the reaction would be self-sustaining.[35] He wanted to carry out a systematic survey of all 92 then-known elements in order to find one that can allow the chain reaction, at an estimated cost of $8000, but he did not for lack of funds.[36]

Szilard filed for a patent on the concept of the neutron-induced nuclear chain reaction in June 1934, which was granted in March 1936.

British Admiralty to ensure its secrecy, which he did.[39] Consequently, his patent was not published until 1949[37] when the relevant parts of the Patents and Designs Act (1907, UK) were repealed by the Patents and Designs Act (July 1949, UK).[40] Richard Rhodes
described Szilard's moment of inspiration:

In London, where

Southampton Row passes Russell Square, across from the British Museum in Bloomsbury,[41] Leo Szilard waited irritably one gray Depression morning for the stoplight to change. A trace of rain had fallen during the night; Tuesday, September 12, 1933, dawned cool, humid and dull. Drizzling rain would begin again in early afternoon. When Szilard told the story later he never mentioned his destination that morning. He may have had none; he often walked to think. In any case another destination intervened. The stoplight changed to green. Szilard stepped off the curb. As he crossed the street time cracked open before him and he saw a way to the future, death into the world and all our woe,[42] the shape of things to come.[43]

Prior to conceiving the nuclear chain reaction, in 1932 Szilard had read H. G. Wells' The World Set Free, a book describing continuing explosives which Wells termed "atomic bombs"; Szilard wrote in his memoirs the book had made "a very great impression on me."[44] When Szilard assigned his patent to the Admiralty to keep the news from reaching the notice of the wider scientific community, he wrote, "Knowing what this [a chain reaction] would mean—and I knew it because I had read H. G. Wells—I did not want this patent to become public."[44]

In early 1934, Szilard began working at

X-rays.[48][49]

Manhattan Project

Columbia University

Szilard visited Béla and Rose and her husband Roland (Lorand) Detre, in Switzerland in September 1937. After a rainstorm, he and his siblings spent an afternoon in an unsuccessful attempt to build a prototype collapsible umbrella. One reason for the visit was that he had decided to emigrate to the United States, as he believed that another war in Europe was inevitable and imminent. He reached New York on the liner

University of Illinois at Urbana–Champaign, and then the University of Chicago, University of Michigan and the University of Rochester, where he undertook experiments with indium but again failed to initiate a chain reaction.[51]

Army Intelligence report on Enrico Fermi and Leo Szilard

In November 1938, Szilard moved to New York City, taking a room at the King's Crown Hotel near

Otto Frisch. When Szilard found out about it on a visit to Wigner at Princeton University, he immediately realized that uranium might be the element capable of sustaining a chain reaction.[52]

Unable to convince Fermi that this was the case, Szilard set out on his own. He obtained permission from the head of the physics department at Columbia,

Frederick Lindemann at Oxford and asked him to send a beryllium cylinder. He persuaded Walter Zinn to become his collaborator and hired Semyon Krewer to investigate processes for manufacturing pure uranium and graphite.[53]

Szilard and Zinn conducted a simple experiment on the seventh floor of Pupin Hall at Columbia, using a radium–beryllium source to bombard uranium with neutrons. Initially nothing registered on the oscilloscope, but then Zinn realized that it was not plugged in. On doing so, they discovered significant neutron multiplication in natural uranium, proving that a chain reaction might be possible.[54] Szilard later described the event: "We turned the switch and saw the flashes. We watched them for a little while and then we switched everything off and went home."[55] He understood the implications and consequences of this discovery, though. "That night, there was very little doubt in my mind that the world was headed for grief".[56]

While they had demonstrated that the fission of uranium produced more neutrons than it consumed, this was still not a chain reaction. Szilard persuaded Fermi and Herbert L. Anderson to try a larger experiment using 500 pounds (230 kg) of uranium. To maximize the chance of fission, they needed a neutron moderator to slow the neutrons down. Hydrogen was a known moderator, so they used water. The results were disappointing. It became apparent that hydrogen slowed neutrons down, but also absorbed them, leaving fewer for the chain reaction. Szilard then suggested Fermi use carbon, in the form of graphite. He felt he would need about 50 tonnes (49 long tons; 55 short tons) (50.8 metric ton) of graphite and 5 tonnes (4.9 long tons; 5.5 short tons) of uranium. As a back-up plan, Szilard also considered where he might find a few tons of heavy water; deuterium would not absorb neutrons like ordinary hydrogen but would have the similar value as a moderator. Such quantities of material would require a lot of money.[57]

Szilard drafted a confidential letter to the President,

Brigadier General Edwin M. "Pa" Watson with the instruction: "Pa, this requires action!"[59]

An Advisory Committee on Uranium was formed under

National Bureau of Standards. Its first meeting on October 21, 1939, was attended by Szilard, Teller, and Wigner, who persuaded the Army and Navy to provide $6,000 for Szilard to purchase supplies for experiments—in particular, more graphite.[60] A 1940 Army intelligence report on Fermi and Szilard, prepared when the United States had not yet entered World War II, expressed reservations about both. While it contained some errors of fact about Szilard, it correctly noted his dire prediction that Germany would win the war.[61]

Fermi and Szilard met with

atomic bomb, and therefore concentrated on producing a controlled chain reaction.[65] Fermi determined that a fissioning uranium atom produced 1.73 neutrons on average. It was enough, but a careful design was called for to minimize losses.[66] Szilard worked up various designs for a nuclear reactor. "If the uranium project could have been run on ideas alone," Wigner later remarked, "no one but Leo Szilard would have been needed."[65]

Metallurgical Laboratory

14 men and one woman, all wearing formal suit jackets, with Szilard also wearing a lab coat
The Metallurgical Laboratory scientists, with Szilard second from right, in the lab coat

At its December 6, 1941, meeting, the

Arthur H. Compton from the University of Chicago was appointed head of research and development. Against Szilard's wishes, Compton concentrated all the groups working on reactors and plutonium at the Metallurgical Laboratory of the University of Chicago. Compton laid out an ambitious plan to achieve a chain reaction by January 1943, start manufacturing plutonium in nuclear reactors by January 1944, and produce an atomic bomb by January 1945.[67]

In January 1942, Szilard joined the Metallurgical Laboratory in Chicago as a research associate, and later the chief physicist.

Ed Creutz on a method for recovering uranium from its salts.[71]

A vexing question at the time was how a production reactor should be cooled. Taking a conservative view that every possible neutron must be preserved, the majority opinion initially favored cooling with helium, which would absorb very few neutrons. Szilard argued that if this was a concern, then liquid

Secretary of War, Henry L. Stimson, refused to do so.[72] Szilard was therefore present on December 2, 1942, when the first man-made self-sustaining nuclear chain reaction was achieved in the first nuclear reactor under viewing stands of Stagg Field and shook Fermi's hand.[73]

Szilard started to acquire high-quality graphite and uranium, which were the necessary materials for building a large-scale chain reaction experiment. The success of this demonstration and technological breakthrough at the University of Chicago were partially due to Szilard's new atomic theories, his uranium lattice design, and the identification and mitigation of a key graphite impurity (boron) through a joint collaboration with graphite suppliers.[74]

Szilard became a

naturalized citizen of the United States in March 1943.[75] The Army offered Szilard $25,000 for his inventions before November 1940, when he officially joined the project. He refused.[76] He was the co-holder, with Fermi, of the patent on the nuclear reactor.[77] In the end he sold his patent to the government for reimbursement of his expenses, some $15,416, plus the standard $1 fee.[78] He continued to work with Fermi and Wigner on nuclear reactor design and is credited with coining the term "breeder reactor".[79]

With an enduring passion for the preservation of human life and political freedom, Szilard hoped that the US government would not use nuclear weapons, but that the mere threat of such weapons would force Germany and Japan to surrender. He also worried about the long-term implications of nuclear weapons, predicting that their use by the United States would start a nuclear arms race with the USSR. He drafted the Szilárd petition advocating that the atomic bomb be demonstrated to the enemy, and used only if the enemy did not then surrender. The Interim Committee instead chose to use atomic bombs against cities over the protests of Szilard and other scientists.[80] Afterwards, he lobbied for amendments to the Atomic Energy Act of 1946 that placed nuclear energy under civilian control.[81]

After the war

Szilard and Norman Hilberry at the site of CP-1, at the University of Chicago, some years after the war. It was demolished in 1957.

In 1946, Szilard secured a research professorship at the University of Chicago that allowed him to research in biology and the social sciences. He teamed up with

feedback inhibition, an important factor in processes such as growth and metabolism.[84] Szilard gave essential advice to Theodore Puck and Philip I. Marcus for their first cloning of a human cell in 1955.[85]

Personal life

Before his relationship with his later wife Gertrud "Trude" Weiss, Leo Szilard's life partner in the period 1927–1934 was the kindergarten teacher and opera singer Gerda Philipsborn, who also worked as a volunteer in a Berlin asylum organization for refugee children and in 1932 moved to India to continue this work.[86] Szilard married Trude Weiss,[87] a physician, in a civil ceremony in New York on October 13, 1951. They had known each other since 1929 and had frequently corresponded and visited each other ever since. Weiss took up a teaching position at the University of Colorado in April 1950, and Szilard began staying with her in Denver for weeks at a time when they had never been together for more than a few days before. Single people living together was frowned upon in the conservative United States at the time and, after they were discovered by one of her students, Szilard began to worry that she might lose her job. Their relationship remained a long-distance one, and they kept news of their marriage quiet. Many of his friends were shocked, having considered Szilard a born bachelor.[88][89]

Writings

In 1949 Szilard wrote a short story titled "

doomsday weapon, in theory,[95] but was of the view that, even then, "enough people might find refuge to wait out the radioactivity and emerge to begin again."[93]

In 1961 he proposed the idea of "Mined Cities", an early example of

mutually assured destruction.[96][97]

Szilard published a book of short stories, The Voice of the Dolphins (1961), in which he dealt with the moral and ethical issues raised by the

James Watson and John Kendrew.[98] When the European Molecular Biology Laboratory was established, the library was named The Szilard Library and the library stamp features dolphins.[99] Other honors that he received included the Atoms for Peace Award in 1959,[100] and the Humanist of the Year in 1960.[101] A lunar crater on the far side of the Moon was named after him in 1970.[102] The Leo Szilard Lectureship Award, established in 1974, is given in his honor by the American Physical Society.[103]

Cancer diagnosis and treatment

In 1960, Szilard was diagnosed with

Memorial Sloan-Kettering Hospital using a cobalt 60 treatment regimen that his doctors gave him a high degree of control over. A second round of treatment with an increased dose followed in 1962. The higher dose did its job and his cancer never returned.[104]

Last years

Salk Institute

Szilard spent his last years as a fellow of the Salk Institute for Biological Studies in the La Jolla community of San Diego, California, which he had helped create.[105] Szilard founded Council for a Livable World in 1962 to deliver "the sweet voice of reason" about nuclear weapons to Congress, the White House, and the American public.[106] He was appointed a non-resident fellow there in July 1963, and became a resident fellow on April 1, 1964, after moving to San Diego in February.[107] With Trude, he lived in a bungalow on the property of the Hotel del Charro. On May 30, 1964, he died there in his sleep of a heart attack; when Trude awoke, she was unable to revive him.[108] His remains were cremated.[109]

His papers are in the library at the

National Historical Publications and Records Commission to digitize its collection of his papers, extending from 1938 to 1998.[110]

Patents

Recognition and remembrance

In media

Szilard was portrayed in the 2023 Christopher Nolan film Oppenheimer by Máté Haumann.[112]

See also

Notes

  1. ^ Marx, György. "A marslakók legendája". Retrieved April 7, 2020.
  2. ^ Lanouette & Silard 1992, pp. 10–13.
  3. ^ Lanouette & Silard 1992, pp. 13–15.
  4. ^ Lanouette & Silard 1992, p. 167.
  5. ^ Byers, Nina. "Fermi and Szilard". Retrieved May 23, 2015.
  6. ISBN 978-1-137-02833-4
    . Retrieved July 22, 2023.
  7. ^ Frank 2008, pp. 244–246.
  8. ^ Blumesberger, Doppelhofer & Mauthe 2002, p. 1355.
  9. ISSN 0096-3402
    . Retrieved May 29, 2023.
  10. ^ Lanouette & Silard 1992, pp. 36–41.
  11. ^ Bess 1993, p. 44.
  12. ^ Lanouette & Silard 1992, p. 42.
  13. ^ Lanouette & Silard 1992, pp. 44–46.
  14. ^ Lanouette & Silard 1992, pp. 44–49.
  15. ^ Lanouette & Silard 1992, pp. 49–52.
  16. ^ Lanouette & Silard 1992, pp. 56–58.
  17. ^ Hargittai 2006, p. 44.
  18. S2CID 121162622
    .
  19. ^ Lanouette & Silard 1992, pp. 60–61.
  20. S2CID 122038206. Available on-line in English at Aurellen.org
    .
  21. ^ a b Lanouette & Silard 1992, pp. 62–65.
  22. ^ von Neumann, John (1949). "Review of Norbert Wiener, cybernetics". Physics Today. 2: 33–34.
  23. ^ Kline, Ronald (2015). The cybernetics moment: Or why we call our age the information age. JHU Press.
  24. doi:10.1063/1.1325189
    .
  25. ^ Calaprice & Lipscombe 2005, p. 110.
  26. ^ Lanouette & Silard 1992, pp. 101–102.
  27. ^ Lanouette & Silard 1992, pp. 83–85.
  28. ^ a b Dannen, Gene (February 9, 1998). "Leo Szilard the Inventor: A Slideshow". Retrieved May 24, 2015.
  29. ^ U.S. patent 1,781,541
  30. ^ Fraser 2012, p. 71.
  31. ^ Rhodes 1986, p. 26.
  32. ^ Lanouette & Silard 1992, pp. 119–122.
  33. ^ Lanouette & Silard 1992, pp. 131–132.
  34. ^ Rhodes 1986, p. 27.
  35. ^ Lanouette & Silard 1992, pp. 133–135.
  36. S2CID 4163940
    .
  37. ^ a b GB patent 630726, Leo Szilard, "Improvements in or relating to the transmutation of chemical elements", published 1949-09-28, issued March 30, 1936 
  38. HM Government
    . Retrieved January 7, 2020 – via legislation.gov.uk.
  39. ^ Rhodes 1986, pp. 224–225.
  40. HM Government
    . Retrieved January 7, 2020 – via legislation.gov.uk. Ss. 1–46 repealed by Patents Act 1949 (c. 87), Schs. 2, 3 and Registered Designs Act 1949 (c. 88), s. 48, Sch. 2
  41. ^ "Street corner in London where Szilard conceived the idea of the chain reaction", about 1980. Leo Szilard Papers. MSS 32. Special Collections & Archives, UC San Diego Library.
  42. ^ Quote from Milton, John (1667) "Paradise Lost", Book I, verse 3
  43. ^ Rhodes 1986, p. 13.
  44. ^ a b "H.G. Wells and the Scientific Imagination". The Virginia Quarterly Review. Retrieved August 6, 2022.
  45. S2CID 4129460
    .
  46. S2CID 4111335
    .
  47. ^ Lanouette & Silard 1992, pp. 145–148.
  48. ^ Lanouette & Silard 1992, p. 148.
  49. S2CID 4106665
    .
  50. ^ Lanouette & Silard 1992, pp. 166–167.
  51. ^ a b Lanouette & Silard 1992, pp. 172–173.
  52. ^ Lanouette & Silard 1992, pp. 178–179.
  53. ^ Lanouette & Silard 1992, pp. 182–183.
  54. ^ Lanouette & Silard 1992, pp. 186–187.
  55. ^ Rhodes 1986, p. 291.
  56. ^ Rhodes 1986, p. 292.
  57. ^ Lanouette & Silard 1992, pp. 194–195.
  58. ^ The Atomic Heritage Foundation. "Einstein's Letter to Franklin D. Roosevelt". Archived from the original on June 17, 2022. Retrieved May 26, 2007.
  59. ^ The Atomic Heritage Foundation. "Pa, this requires action!". Archived from the original on October 29, 2012. Retrieved May 26, 2007.
  60. ^ Hewlett & Anderson 1962, pp. 19–21.
  61. ^ Lanouette & Silard 1992, pp. 223–224.
  62. ^ Weinberg 1994b.
  63. ^ Lanouette & Silard 1992, p. 222.
  64. doi:10.1063/1.1292473
    .
  65. ^ a b Lanouette & Silard 1992, p. 227.
  66. ^ Hewlett & Anderson 1962, p. 28.
  67. ^ a b Lanouette & Silard 1992, pp. 227–231.
  68. ^ a b Weinberg 1994a, pp. 22–23.
  69. ^ Weinberg 1994a, p. 17.
  70. ^ Weinberg 1994a, p. 36.
  71. ^ Lanouette & Silard 1992, pp. 234–235.
  72. ^ Lanouette & Silard 1992, pp. 238–242.
  73. ^ Lanouette & Silard 1992, pp. 243–245.
  74. ^ Leo Szilard article of the Atomic Heritage Foundation [1]
  75. ^ Lanouette & Silard 1992, p. 249.
  76. ^ Lanouette & Silard 1992, p. 253.
  77. ^ U.S. patent 2,708,656
  78. ^ Lanouette & Silard 1992, p. 254.
  79. ^ Weinberg 1994a, pp. 38–40.
  80. ^ Lanouette & Silard 1992, pp. 266–275.
  81. ^ a b Lanouette & Silard 1992, pp. 377–378.
  82. ISSN 1521-9615. The chemostat was independently invented the same year by Jacques Monod
    .
  83. PMID 14787503
    .
  84. ^ Hargittai 2006, pp. 143–144.
  85. ^ Lanouette & Silard 1992, pp. 395–397.
  86. ^ Dannen, Gene (January 26, 2015). "Physicist's Lost Love: Leo Szilard and Gerda Philipsborn". dannen.com. Retrieved January 24, 2016.
  87. ^ "Trude Weiss Szilard interviewed by Harold Keen at the Jewish Community Center". 1980.
  88. ^ Esterer & Esterer 1972, p. 148.
  89. ^ Lanouette & Silard 1992, pp. 334–339.
  90. ^ Jogalekar, Ashutosh (February 18, 2014). "Why the world needs more Leo Szilards". Scientific American. Retrieved May 29, 2015.
  91. ^
    doi:10.1080/00963402.1950.11461233
    .
  92. ^ Lanouette & Silard 1992, pp. 317, 366.
  93. ^ a b "Science: fy for Doomsday". Time. November 24, 1961. Archived from the original on March 14, 2016.
  94. doi:10.1080/00963402.1950.11461290
    .
  95. doi:10.1080/00963402.1961.11454268
    .
  96. ISSN 0096-3402
    .
  97. ISBN 978-1-78499-440-2
    , retrieved September 3, 2023
  98. ^ "Brief History". European Molecular Biology Laboratory. Archived from the original on April 13, 2014. Retrieved February 22, 2011.
  99. ^ "Szilard Library". European Molecular Biology Laboratory. Retrieved February 22, 2011.
  100. ^ "Guide to Atoms for Peace Awards Records MC.0010". Massachusetts Institute of Technology. Archived from the original on August 5, 2015. Retrieved May 19, 2015.
  101. ^ "The Humanist of the Year". American Humanist Association. Archived from the original on January 14, 2013. Retrieved May 29, 2015.
  102. United States Geographical Survey
    . Retrieved May 29, 2015.
  103. ^ "Leo Szilard Lectureship Award". American Physical Society. Retrieved March 25, 2016.
  104. OCLC 857364771
    .
  105. ^ Lanouette & Silard 1992, pp. 400–401.
  106. ^ "Founding". Council for a Livable World. Retrieved April 7, 2020.
  107. ^
    University of California in San Diego
    . Retrieved May 29, 2015.
  108. ^ Lanouette & Silard 1992, p. 477.
  109. ^ Lanouette & Silard 1992, p. 479.
  110. ^ Davies, Dolores. "Materials Documenting Birth of Nuclear Age to be Digitized". Retrieved May 29, 2015.
  111. ^ 38442 Szilard (1999 SU6)
  112. ^ Moss, Molly; Knight, Lewis (July 22, 2023). "Oppenheimer cast: Full list of actors in Christopher Nolan film". Radio Times. Retrieved July 24, 2023.

References

Further reading

External links

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