1. Sir Rudolf Ernst Peierls, Bird of Passage: Recollections of a Physicist (Princeton: Princeton University Press, 1985).

1. On the Villa d'Este, see D. R. Coffin, The Villa d'Este at Tivoli (Princeton: Princeton University Press, 1960), and C. Lamb, Die Villa d'Este in Tivoli (Munich: Prestel Verlag, 1968).

2. In 1986, in the Brera Library in Milan, I found a copy of the issue of Scienza per tutti dated March I, 1914, which contains the articles mentioned.

3. See Il collegio Ghislieri (Milan: Alfieri e Lacroix, 1967), esp. p. 415. On Claudio Segrè, see L. Maddalena, "Claudio Segrè," Boll. soc. geologica italiana 47 (1928); A. Stella, "Commemorazione del socio Claudio Segrè," Rend. acc. naz. Lincei (scienze fisiche) 10 (1927): xi. On Gino Segrè, see G. Grosso, "Gino Segrè," Temi emiliana 19 (Milan, 1942); A. Candian et al., "Si respira nell'altitudine," Temi (Milan, 1962); Provincia di Torino, Consegna del medaglione in memoria di G. Segrè (Turin, 1963); V. Arangio-Ruiz, "Commemorazione del Socio Gino Segrè,'' Rend. acc. naz. Lincei (scienze morali) 2 (1947): 607; E. Betti, "Gino Segrè," Riv. italiana sc. giuridiche 18 (1942): 200, 302.

4. I myself have frequently been confused with the mathematician Beniamino Segre (whose name is written without the accent), and even with his famous cousin Corrado. Once, knowing that I was coming to visit him, Fabio Ferrari, a theoretician who studied with Geoffrey Chew, and who subsequently became rector of the University of Trento, made his young son read an article about me in an Italian encyclopedia; in it, under my name, there was a portrait of Beniamino Segre, and as soon as he saw me,

the little boy declared that I was not the man for whom he had prepared himself.

On another occasion, I placed a person-to-person call to Elfriede, who was in different city. The operator had some difficulty in understanding the name, but suddenly he said: "Ah, Segrè, like the physicist?" I felt flattered at being recognized and said: "Exactly. Actually, I am the physicist." Operator: "That is not possible, because that one is dead." I insisted: ''I can assure you that I am the physicist and that I am alive." Operator: "That cannot be true because I have read your name on a street in my neighborhood, near Piazza or Via Fermi, and streets are named only after people who are dead." When I checked later, sure enough, near Piazza Fermi, there was a Via Corrado Segre.

5. My late cousin Silvia Treves Vidale wrote a privately circulated monograph on the Treves family. The Florence synagogue designed by my grandfather Marco Treves, and by M. Falcini and V. Micheli, is depicted on a 1987 Israeli postage stamp.

6. On Guido Treves, see A. Sapori, Compagnie e mercanti di Firenze antica (Florence, 1965); G. Devoto, Civiltà di parole (Florence: Vallecchi, 1969), vol. 2.

7. Among the paintings of Ettore Roesler Franz (1845-1907) is a series of watercolors titled Roma sparita (Vanished Rome), now at the Museo di Roma in Rome; many of them have been reproduced as postcards. Franz sold his watercolors to tourists as souvenirs, in the tradition of the Venetian Canaletto. I bought two such paintings at auctions in San Francisco.

8. Gaston Tissandier, Le ricreazioni scientifiche (Milan: Treves, 1897).

9. Adolphe Ganot, Trattato elementare di fisica (Milan: Pagnoni, 1863).

10. Ganot-Maneuvrier, Traite élémentaire de physique , 25th ed. (Paris: Hachette, 1913).

1. The translation is from Ernesto Grillo, ed. and trans., I sepolcri in Italian and English (London and Glasgow: Blackie and Son, 1928).

2. For Enzo Sereni, see R. Bondy, The Emissary: A Life of Enzo Sereni (Boston: Little, Brown, 1977), as well as D. V. Segre, Memories of a Fortunate Jew (Bethesda, Md.: Adler & Adler, 1987); the latter author's impressions are not too different from mine. Enzo's brother Emilio became a prominent member of the Italian Communist Party; see Enciclopedia europea, s.v. "Sereni, Emilio" (Milan: Garzanti, 1980).

3. Sir Richard Glazebrook, Light: An Elementary Textbook  . . . for Colleges and Schools (Cambridge: Cambridge University Press, 1894); Sir Robert S. Ball, The Elements of Astronomy (New York: Longmans, 1891); James Clerk

Maxwell, Theory of Heat (New York: Appleton, 1875); Fritz Reiche, The Quantum Theory (New York: Dutton, [1922?]).

4. Albert Einstein, the Human Side: New Glimpses from His Archives, ed. Helen Dukas and Banesh Hoffmann (Princeton: Princeton University Press, 1979), p. 32.

5. See B. J. Moyer: A True Humanist (pamphlet in memoriam, Eugene: University of Oregon, 1972).

1. Walther Nernst, Theoretische Chemie vom Standpunkte der Avogadroschen Regel und der Thermodynamik . I read a French translation of this work, which I found among the books of my brother Angelo.

2. The course was later published as T. Levi-Civita and U. Amaldi, Compendio di meccanica razionale (Bologna: Zanichelli, 1928).

3. Much has been written on Majorana, often pure fiction. For a serious life, see Edoardo Amaldi, "E. Majorana: Man and Scientist," in Strong and Weak Interactions , ed. A. Zichichi (New York: Academic Press, 1966). See also E. Segrè, Storia contemporanea, vol. 19 (Bologna, 1988), p. 107.

4. Enrico Fermi "Sui principi della teoria dei quanti" (On the principles of quantum theory). FP22. The general reference for all scientific publications by Fermi is Enrico Fermi, Collected Papers , ed. E. Segrè et al. (Chicago: University of Chicago Press, 1961). Single papers are cited by the notation FP, followed by the number in Collected Papers . For biographical data, see E. Segrè, Enrico Fermi, Physicist (Chicago: University of Chicago Press, 1970), and Enrico Fermi, fisico (Bologna: Zanichelli, 1971, 1987), as well as Laura Fermi, Atoms in the Family: My Life with Enrico Fermi (1954; New York: Tomash Publishers / American Institute of Physics, 1987).

5. On Franco Rasetti, see T. Nason, "A Man for All Sciences," Johns Hopkins Magazine 17 (1966): 12.

6. On the Volta Conference at Como, see Atti del congresso int. dei fisici (11-20 sett. 1927 Como- Pavia- Roma) pubblicati a cura del comitato per le onoranze ad A. Volta nel primo centenario della morte (Bologna: Zanichelli, 1928).

7. Enrico Fermi and Franco Rasetti, "Una misura del rapporto h/k per mezzo della dispersione anomala del tallio" (A measurement of the ratio h/k using anomalous dispersion in thallium). FP40b.

8. FP2: 673.

9. Laura Fermi vividly describes the company in Atoms in the Family .

10. On O. M. Corbino, see Conferenze e discorsi di O. M. Corbino (Rome: Edizioni Enzo Pinci, 1937), and Epicarmo Corbino, Racconto di una vita

(Naples: Edizioni scientifiche italiane, 1972), as well as Gli atti del convegno ai Lincei nel cinquantenario della morte , the proceedings of a conference at Lincei on the fiftieth anniversary of Corbino's death.

11. Enrico Fermi "Un metodo statistico per la determinazione di alcune proprietà dell'atomo" (A statistical method for the determination of some atomic properties). FP43.

12. On Edoardo Amaldi, see E. Segrè, "Italian Physics in Amaldi's Time," and Edoardo Amaldi, "The Years of Reconstruction," in Perspectives of Fundamental Physics: Proceedings of the Conference Held at the University of Rome, 7-9 September 1978, Dedicated to Edoardo Amaldi , ed. Carlo Schaerf (New York: Harwood Academic Publishers, 1979).

13. E. Segrè and Edoardo Amaldi, "Sulla dispersione anomala del mercurio e del litio" (On anomalous dispersion in mercury and in lithium), Rend. Lincei , ser. 6, 7 (1928): 407-9.

14. See, on this, Laura Fermi, Atoms in the Family , pp. 69-73.

1. See chapter 3, n. 13.

2. Edoardo Amaldi and E. Segrè, "Sulla teoria dell'effetto Raman" (Quantum theory of the Raman effect), Rend. Lincei , ser. 6, 9 (1929): 407-9.

3. E. Segrè, "Sulla dispersione anomala negli spettri di bande" (Anomalous dispersion in band spectra), Rend. Lincei , ser. 6, 10 (1929): 590-94. See also Nuovo cimento 4 (1930): 144-47.

4. See FP1: 444, 445.

5. F. Rasetti, "Raman Effekt und Struktur der Molekeln und Kristalle," in Peter J. W. Debye, Leipziger Vorträge, 1931 (Leipzig: S. Hirzel, 1931).

6. E. Segrè, "Evidence for Quadrupole Radiation," Nature 126 (1930): 882.

7. E. Segrè, "Über den Zeemaneffekt von Quadrupollinien" (On the Zeeman effect of quadrupole lines), Zs. f. Physik 66 (1930): 827-29.

8. On Zeeman, see the obituary by Lord Rayleigh in Obituary Notices of Fellows of the Royal Society of London 4 (1944): 591.

9. On Cornelius J. Bakker (1904-60), see Armin Hermann et al., History of CERN, vol. 1 (Amsterdam and New York: North-Holland Physics Pub., 1987), pp. 127, 158.

10. See E. Segrè, "Righe di quadrupolo negli spettri di raggi X" (Quadrupole lines in X-ray spectra), Rend. Lincei , ser. 6, 14 (1931): 501-5.

11. Arnold Sommerfeld, Atombau und Spektrallinien: Wellenmechanischer Ergänzungsband, vol. 2 (Braunschweig: F. Vieweg, 1939).

12. See E. Segrè, "Otto Stern," in Nat. Ac. of Sciences, Biographical

Memoirs, vol. 43 (Washington, D.C.: National Academy of Sciences, 1973), p. 215.

13. Otto Frisch has written an autobiography entitled What Little I Remember (Cambridge and New York: Cambridge University Press, 1979).

14. Friedrich von Schiller, "Sprüche des Konfucius." One of Niels Bohr's favorite quotations, "Nur die Fülle führt zur Klarheit / Und im Abgrund wohnt die Wahrheit" (Naught but fulness makes us wise,— / Buried deep, truth ever lies!) comes from the same poem. The translation is from Poems of Schiller (New York: John D. Williams, n.d.).

15. Adrienne Thomas's antiwar novel Die Katrin wird Soldat (Berlin: Ullstein Verlag, 1930; Frankfurt am Main: Fischer Taschenbuch, 1987).

16. Enrico Fermi and E. Segrè, "Sulla teoria delle strutture iperfini" (On the theory of hyperfine structure), Reale acc. d'Italia, memorie cl. scienze fisiche 4 (1933): 131-58, summarized in "Zur Theorie der Hyperfeinstruktur," Zs. f. Physik 82 (1933): 729-49, and in Nuovo cimento 7 (1934). FP75b.

17. E. Segrè and C. J. Bakker, "Zeeman Effect of a Forbidden Line," Nature 128 (1931): 1076.

18. E. Segrè, "Un metodo per l'osservazione dell'effetto Zeeman quadratico" (A method for observing the quadratic Zeeman effect), Ricerca scientifica 4, no. 2 (1933): 531, and "Effetto Zeeman quadratico nella serie principale del sodio" (Quadratic Zeeman effect in the principal sodium series), Nuovo cimento 5 (1934): 304-8.

19. Edoardo Amaldi and E. Segrè, "Einige spektroskopische Eigenschaften hochangeregter Atome" (Some spectroscopic properties of highly excited atoms), in Zeeman Verhandelingen (The Hague: Martinus Nijhoff, 1935), pp. 8-17.

20. R. Frisch and E. Segrè, "Über die Einstellung der Richtungsquantelung II" (On the dynamics of space quantization), Zs. f. Physik 80 (1933): 610-16; also R. Frisch and E. Segrè, "Ricerche sulla quantizzazione spaziale" (Investigation of spatial quantization), Nuovo cimento 2 (1933): 78-91; and see I. I. Rabi, "On the Process of Space Quantization," Phys. Rev. 49 (1936): 324.

21. Ernest Rutherford, James Chadwick, and C. D. Ellis, Radiations from Radioactive Substances (Cambridge: Cambridge University Press, 1930).

22. E. Amaldi, O. D'Agostino, E. Fermi, F. Rasetti, and E. Segrè, "Radioattività 'beta' provocata da bombardamento di neutroni, III" (Beta radioactivity produced by neutron bombardment, III), La ricerca scientifica (henceforth cited as RS ) 5, no. 1 (1934): 452-53 [FP86a]; E. Amaldi, O. D'Agostino, E. Fermi, F. Rasetti, and E. Segrè, "Radioattività provocata da bombardamento di neutroni, IV" (Radioactivity produced by neutron bombardment, IV), RS 5, no. 1 (1934): 652-53 [FP87a]; E. Amaldi, O. D'Agostino, E. Fermi, F. Rasetti, and E. Segrè, "Radioattività provocata

da bombardamento di neutroni, V" (Radioactivity produced by neutron bombardment, V), RS 5, no. 2 (1934): 21-22 [FP88a]; E. Amaldi, O. D'Agostino, and E. Segrè, "Radioattività provocata da bombardamento di neutroni, VI" (Radioactivity produced by neutron bombardment, VI), RS 5, no. 2 (1934): 38-82; E. Amaldi, O. D'Agostino, E. Fermi, B. Pontecorvo, F. Rasetti, and E. Segrè, "Radioattività provocata da bombardamento di neutroni, VII" (Radioactivity produced by neutron bombardment, VII), RS 5, no. 2 (1934): 467-70 [FP89a]; E. Amaldi, O. D'Agostino, E. Fermi, B. Pontecorvo, F. Rasetti, and E. Segrè, "Radioattività provocata da bombardamento di neutroni, VIII" (Radioactivity produced by neutron bombardment, VIII), RS 6, no. 1 (1935): 123-25 [FP90a]; E. Amaldi, O. D'Agostino, E. Fermi, B. Pontecorvo, and E. Segrè, "Radioattività indotta da bombardamento di neutroni, IX" (Radioactivity induced by neutron bombardment, IX), RS 6, no. 1 (1935): 435-37 [FP91a]; E. Amaldi, O. D'Agostino, E. Fermi, B. Pontecorvo, and E. Segrè, ''Radioattività indotta da bombardamento di neutroni, X" (Radioactivity induced by neutron bombardment, X), RS 6, no. 1 (1935): 581-84 [FP92a]. And see Segrè, Enrico Fermi, Physicist, pp. 73 ff.

23. See E. Segrè, "A cinquant'anni dalla radioattività artificiale provocata da neutroni," Rendiconti della Accademia nazionale delle scienze, detta dei XL, memorie fis., 5th ser., 8, pt. 2 (1984): 165.

24. Aristide von Grosse, "The Chemical Properties of Elements 93 and 94," J. Am. Chem Soc. 57 (1935): 440-41; E. Segrè, "An Unsuccessful Search for Transuranic Elements," Phys. Rev. 55 (1939): 1104-5; G. E. Villar, Boletín de la Facultad de ingeniería (Montevideo) 5 (1938): 231. These papers preceded the discovery of neptunium by Edwin McMillan and Philip Abelson. If the writings of Aristide von Grosse and of Ida Noddack (see n. 25 below) had been better appreciated, the whole history of fission and of the transuranics would have been different. The following papers appeared after the discovery of neptunium: M. Mayer, "Rare Earths and Transuranic Elements," Phys. Rev. 60 (1941): 184; G. T. Seaborg and E. Segrè, "The Trans-Uranium Elements," Nature 159 (1947): 863-65. Starting in 1944, Seaborg developed the concept of an actinide family; see, e.g., The Transuranium Elements, ed. G. T. Seaborg, J. J. Katz, and W. M. Manning (New York: McGraw-Hill, 1949): 1517-20. Seaborg's personal recollections may be found in The Transuranium Elements (New Haven: Yale University Press, 1957).

25. Ida Noddack, "Über das Element 93," Angew. Chemie 47 1934): 653-55.

26. Otto Hahn and Fritz Strassmann, "Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle," Naturwiss . 27 (1939): 39. The history of the discovery of fission is very complicated: important original sources are FP;

Frédéric Joliot and Irène Curie, Oeuvres scientifiques complètes (Paris: Presses universitaires de France, 1961); Otto Hahn, Vom Radiothor zur Uranspaltung: Eine wissenschaftliche Selbstbiographie (Braunschweig: Vieweg, 1962); and Fritz Krafft, Im Schatten der Sensation: Leben und Wirken von Fritz Strassmann (Weinheim: Verlag Chemie, 1981).

27. E. Fermi, E. Amaldi, O. D'Agostino, F. Rasetti, and E. Segrè, "Artificial Radioactivity Produced by Neutron Bombardment," Proc. Roy. Soc. (London) A146 (1934): 483-500. FP98.

27. E. Fermi, E. Amaldi, O. D'Agostino, F. Rasetti, and E. Segrè, "Artificial Radioactivity Produced by Neutron Bombardment," Proc. Roy. Soc. (London) A146 (1934): 483-500. FP98.

28. Enrico Fermi, "Natural Beta Decay" (Int. Conf. on Physics, London, 1934), in Nuclear Physics (London: Physical Society, 1934), vol. 1. FP102.

28. Enrico Fermi, "Natural Beta Decay" (Int. Conf. on Physics, London, 1934), in Nuclear Physics (London: Physical Society, 1934), vol. 1. FP102.

28. Enrico Fermi, "Natural Beta Decay" (Int. Conf. on Physics, London, 1934), in Nuclear Physics (London: Physical Society, 1934), vol. 1. FP102.

29. E. Fermi, E. Amaldi, B. Pontecorvo, F. Rasetti, and E. Segrè, "Azione di sostanze idrogenate sulla radioattività provocata da neutroni" (The influence of hydrogenous substances on the radioactivity produced by neutrons), Ricerca scientifica 5 (1934): 282. FP105a.

30. Fritz Haber received the Nobel Prize for chemistry in 1919 for synthesizing ammonia from its elements.

31. Hermann Luedemann (1880-1959) was an engineer of liberal-socialist tendencies who turned to politics. From 1929 to 1932, he was Oberpräsident of Silesia—the highest civil official in the province—and Elfriede served as his secretary in that office. The Nazis put Luedemann in a concentration camp, but he survived.

32. On Pegram, see L. A. Embrey, "G. B. Pegram," in Nat. Ac. of Sciences, Biographical Memoirs, vol. 61 (Washington, D.C.: National Academy of Sciences, 1970), p. 357.

33. See J. R. Dunning, G. A. Fink, G. B. Pegram, and E. Segrè, "Experiments on Slow Neutrons with Velocity Selector," Phys. Rev. 49 (1936): 198-99; G. A. Fink, J. R. Dunning, G. B. Pegram, and E. Segrè, "Production and Absorption of Slow Neutrons in Hydrogenic Materials," Phys. Rev. 49 (1936): 199. Also see F. Rasetti, E. Segrè, G. A. Fink, J. R. Dunning, and G. B. Pegram, "Sulla legge di assorbimento dei neutroni lenti," Rend. Lincei, 6th ser., 23 (1936): 343-45, and ''On the Absorption Law for Slow Neutrons," Phys. Rev. 49 (1936): 104.

1. See U. Panichi; "Commemorazione del Corrispondente Carlo Perrier," Rend. Lincei 6 (1949): 386.

2. There is still a copy of the lecture notes for this course in the library of the Palermo Physics Institute.

3. G. Bernardini, G. Gentile, Jr., and G. Polvani, Questioni di fisica (Physics topics) (Florence: Sansoni, 1947). Only the first volume was pub-

lished. The planned contents of the other two are given in it, but they never appeared.

4. On Lawrence, see Herbert Childs, An American Genius: The Life of Ernest Orlando Lawrence, Father of the Cyclotron (New York: Dutton, 1968), and J. L. Heilbron and Robert W. Seidel, Lawrence and His Laboratory: A History of the Lawrence Berkeley Laboratory , vol. 1 (Berkeley and Los Angeles: University of California Press, 1989). I thank the authors for access to the manuscript of the latter book.

5. See E. M. McMillan, "The Transuranium Elements: Early History," in Les Prix Nobel in 1951 (Stockholm: Nobelstiftung, 1952), pp. 165-73.

6. Abelson later collaborated with McMillan in the discovery of neptunium. In time he became director of the Carnegie Institution of Washington and editor in chief of Science . His scientific work was mostly in geochemistry and isotope separation. See also L. W. Alvarez, Adventures of a Physicist (New York: Basic Books, 1987), ch. 4, and E. Segrè, "A cinquant'anni dalla radioattività artificiale provocata da neutroni," Rendiconti della Accademia nazionale delle scienze, detta dei XL, memorie fis., 5th ser., 8, pt. 2 (1984): 165.

7. There is a vast literature, often fictional in character, on Oppenheimer. See esp. Robert Oppenheimer: Letters and Recollections, ed. A. K. Smith and C. Weiner (Cambridge, Mass.: Harvard University Press, 1980).

8. See C. Artom, G. Sarzana, C. Perrier, M. Santangelo, and E. Segrè, "Rate of Organification of Phosphorus in Animal Tissue," Nature 139 (1937): 836-38, and "Phospholipid Synthesis during Fat Absorption," Nature 139 (1937): 1105-6.

9. From my laboratory notebooks for 1937.

10. C. Perrier and E. Segrè, "Alcune proprietà chimiche dell'elemento 43," Rend. Lincei, 6th ser., 25 (1937): 723-30, and 27 (1937): 579-81. Also "Some Chemical Properties of Element 43," Journ. of Chem. Phys. 5 (1937): 71216, and 7 (1939): 155-56.

11. We know today that the longest lived isotopes of technetium have a period of 4.2 million years, a time too short to permit survival from primordial material. Minute amounts of technetium produced in nature by the spontaneous fission of uranium were detected by P. K. Kuroda et al. in 1961.

12. Claimants to the discovery of Element 43 prematurely called it ilmenium, davyum, lucium, nipponium, and masurium, among other names, but their claims were not substantiated. See H. W. Kirby, "Technetium," Gmelin Handbook of Inorganic Chemistry, 8th ed. (Berlin: Springer, 1982).

13. See Hilde Levi, George de Hevesy: Life and Work (Copenhagen: Rhodos, 1985).

14. C. Perrier and E. Segrè, "Technetium: The Element of Atomic Number 43," Nature 159 (1947): 24.

15. See E. Segrè, "Italian Physics in Amaldi's Time," and Edoardo Amaldi, "The Years of Reconstruction," in Perspectives of Fundamental Physics: Proceedings of the Conference Held at the University of Rome, 7-9 September 1978, Dedicated to Edoardo Amaldi , ed. Carlo Schaerf (New York: Harwood Academic Publishers, 1979).

16. See also Edoardo Amaldi, "E. Majorana: Man and Scientist," in Strong and Weak Interactions, ed. A. Zichichi (New York: Academic Press, 1966), and E. Segrè, in Storia contemporanea , vol. 19 (Bologna, 1988), p. 107.

1. For the text and the signers of the Manifesto della razza , and on the subsequent period, see R. De Felice, Storia degli Ebrei italiani sotto il fascismo (History of the Italian Jews under Fascism), 3d ed. (Turin: Einaudi, 1972).

2. On Jenkins, see In Memoriam , University of California, Berkeley, 1962, F. A. Jenkins, 1899-1960. On Brode, see ibid. 1986, R. B. Brode (1900-1986), p. 2.

3. On the history of the Radiation Laboratory, see the works cited in chapter 5, n. 4.

4. See works cited in chapter 5, nn. 5, 6.

5. See Martin D. Kamen, Radiant Science, Dark Politics: A Memoir of the Nuclear Age (Berkeley and Los Angeles: University of California Press, 1985), which vividly portrays the Radiation Laboratory and the scientific climate in the United States before the war.

6. See A. A. Noyes and W. C. Bray, A System of Qualitative Analysis for the Rare Elements (New York: Macmillan, 1927).

7. Tables of natural radioactive isotopes go back to Curie, Rutherford, and their colleagues. With the discovery of artificial radioactivity, they became much larger. A first one was drawn up in Rome by our group and by G. Fea. I drew a useful diagram, following Heisenberg, while still in Rome. Later keeping such tables current required several people, and these days isotope tables are as thick as telephone directories.

8. E. Segrè and G. T. Seaborg, "Nuclear Isomerism in Element 43," Phys. Rev. 54 (1938): 772; ibid. 55 (1939): 808.

9. See also the work cited in chapter 5, n. 7, as well as U.S. Atomic Energy Commission, In the Matter of J. Robert Oppenheimer: Transcript of Hearing before Personnel Security Branch and Texts of Principal Documents and Letters (1954; Cambridge, Mass.: MIT Press, 1971), which gives a vivid picture, not only of Oppenheimer, but also of many other persons who testified at those hearings, among them Edward Teller, L.W. Alvarez, W. M. Latimer, H. A. Bethe, General Leslie Groves, and I. I. Rabi.

10. L. I. Schiff, Quantum Mechanics (New York: McGraw-Hill, 1955).

11. On S. K. Allison, see Bull. Atomic Scientists 22 (1966): 2.

12. F. A. Jenkins and E. Segrè, "The Quadratic Zeeman Effect," Phys. Rev. 55 (1939): 52.

13. E. Segrè, R. S. Halford, and G. T. Seaborg, "Chemical Separation of Nuclear Isomers," Phys. Rev. 55 (1939): 55.

14. E. Segrè, "An Unsuccessful Search for Transuranic Elements," Phys. Rev. 55 (1939): 1104.

15. E. Segrè and C. S. Wu, "Some Fission Products of Uranium," Phys. Rev. 57 (1940): 552, and "Radioactive Xenons," ibid. 67 (1945): 142.

16. On Placzek, see also Edoardo Amaldi, "George Placzek (1905-1955)," Ricerca scientifica 26 (1956): 2038.

17. Cornog, in Discovering Alvarez: Selected Works of Luis W. Alvarez, with Commentary by His Students and Colleagues, ed. W. P. Trower (Chicago: University of Chicago Press, 1987), p. 26. And see D. R. Corson, K. R. MacKenzie, and E. Segrè, "Possible Production of Radioactive Isotopes of Element 85," Phys. Rev. 57 (1940): 459, and "Artificially Radioactive Element 85," ibid. 58 (1940): 672-78.

18. E. Fermi and E. Segrè, "Fission of Uranium by Alpha Particles," Phys. Rev. 59 (1941); 59. FP135.

19. E. Segrè, "Possibility of Altering the Decay Rate of a Radioactive Substance," Phys. Rev. 71 (1947): 274; R. F. Leininger, E. Segrè, and C. E. Wiegand, "Experiments on the Effect of Atomic Electrons on the Decay Constant of Be7," Phys. Rev. 76 (1949): 897, and ibid. 81 (1951): 284.

20. See V. A. Johnson, Karl Lark-Horovitz: Pioneer in Solid State Physics (New York: Pergamon, 1969).

21. Birge was well known for his studies on molecular spectra and on universal constants, and also an important administrator at the University of California, to which he was deeply devoted. One of the physics buildings at Berkeley bears his name, well-deserved recognition of his work. See E. McMillan, "R. T. Birge, 1887-1980," in Am. Phil. Soc. (Philadelphia), Year-book, 1981 , p. 430.

22. R. T. Birge, "History of the Physics Department" (University of California, Berkeley, 1966-?; 5 vols., mimeographed).

23. See the documentation in G. T. Seaborg, Early History of Heavy Isotope Research at Berkeley , Lawrence Berkeley Laboratory Publication No. 97 (Berkeley, 1976). The archives of the Bancroft Library at the University of California, Berkeley, contain much additional material, including a letter from Segrè to Fermi dated January 11th, 1941, signaling the beginning of the work.

24. Many of these documents are to be found in the Bancroft Library.

25. G. T. Seaborg and E. Segrè, "The Transuranium Elements," Nature 159 (1947): 159; E. Segrè, E. M. McMillan, J. W. Kennedy, and A. C. Wahl,

"An Account of the Discovery and Early Study of Element 94," UCRL report No. 2791, Dec. 23, 1942.

26. Letter of G. T. Seaborg to Fermi, January 11, 1941, Bancroft Library.

27. J. W. Kennedy, G. T. Seaborg, E. Segrè, and A. C. Wahl, "Properties of 94 ²³⁹ ," Phys. Rev. 70 (1946): 555-56.

28. On A. L. Loomis, see L. W. Alvarez in Nat. Ac. of Sciences, Biographical Memoirs, vol. 51 (Washington, D.C.: National Academy of Sciences, 1980), p. 309.

29. See J. W. Kennedy and E. Segrè, "Component Analysis of Small Uranium Samples," Manhattan District Report MDDC-973, March 26, 1943.

30. E. Segrè, "Artificial Radioactivity and the Completion of the Periodic System of the Elements," Scientific Monthly 57 (1943): 57.

31. See, e.g., H. D. Smyth, Atomic Energy for Military Purposes (Princeton: Princeton University Press, 1945), the first and justly famous report on the atomic bomb. For details and documentation, consult R. G. Hewlett and O. E. Anderson, Jr., A History of the United States Atomic Energy Commission, vol. 1, The New World, 1939/1946 (University Park, Pa.: Pennsylvania State University Press, 1962).

32. A letter to Fermi written in 1942, now in the Bancroft Library, gives my feelings about going to Los Alamos.

1. The translation is from Schiller's Historical Dramas (New York: John D. Williams, n.d.).

2. Leslie R. Groves, Now It Can Be Told (New York: Harper & Row, 1962). See also K. D. Nichols, The Road to Trinity: A Personal Account of How America's Nuclear Policies Were Made (New York: Morrow, 1987).

3. On wartime Los Alamos, see Reminiscences of Los Alamos, 1943-1945 , ed. Lawrence Badash, Joseph O. Hirschfelder, and Herbert P. Broida (Boston: Reidel, 1980), and Laura Fermi, Atoms in the Family . For a bibliography, see Richard Rhodes The Making of the Atomic Bomb (New York: Simon & Schuster, 1987), a well-written and accurately researched and documented work.

4. Winston S. Churchill, The Second World War , vol. 4, The Hinge of Fate (London: Cassel, 1951), p. 3.

5. Robert Serber, "The Los Alamos Primer" (Los Alamos, N. Mex.: University of California, Los Alamos Scientific Laboratory, photocopied typescript, 1973). Notes by E. U. Condon based on five introductory lectures given by Robert Serber in April 1943 in connection with the Manhattan Project. Declassified "secret limited," February 25, 1963. The titles

of the sections are: 1. Object; 2. Energy of fission process; 3. Fast neutron chain reaction; 4. Fission cross-sections; 5. Neutron spectrum; 6. Neutron number; 7. Neutron capture; 8. Why ordinary U is safe; 9. Material 49 (Pu ²³⁹ ); 10. Simplest estimate of minimum size of bomb; 11. Effect of tamper; 12. Damage; 13. Efficiency; 14. Effect of tamper on efficiency; 15. Detonation; 16. Probability of predetonation; 17. Fizzles; 18. Detonating source; 19. Neutron background; 20. Shooting; 21. Autocatalytic methods; 22. Conclusion.

6. See A. O. Nier, "J. H. Williams," in Nat. Ac. of Sciences, Biographical Memoirs, vol. 42 (Washington, D.C.: National Academy of Sciences, 1971), p. 339.

7. Josef Rotblat subsequently devoted himself to the Pugwash Movement and to the search for solutions to the immense problems created by atomic arms.

8. The first modest table of isotopes was published by a student in our group in Rome in the 1930s; see G. Fea, "Tabelle riassuntive e bibliografia delle trasmutazioni artificiali" (Comprehensive tables and bibliography of artificial transmutations), Nuovo cimento 12 (1935): 368-407. A similar compilation edited by C. M. Lederer and V. Shirley, Table of Isotopes (New York: Wiley, 1978), required 1,523 pages.

9. On G. I. Taylor, see Biog. Mem. Fell. R. Soc. vol. 22 (1976), p. 565.

10. E. Segrè, "Spontaneous Fission," Phys. Rev. 86 (1952): 21.

11. See Richard P. Feynman, Surely You Are Joking, Mr. Feynman! Adventures of a Curious Character (New York: Norton, 1985), pp. 120-21. A letter by Teller reported in Stanley A. Blumberg and Gwinn Owens, Energy and Conflict: The Life and Times of Edward Teller (New York: Putnam, 1976), p. 457, refers to the same episode. I do not remember having had exchanges with Teller on this subject at the time.

12. On the Trinity test, see W. L. Laurence, Dawn over Zero: The Story of the Atomic Bomb (New York: Knopf, 1946).

1. R. T. Birge, "History of the Physics Department" (Berkeley: University of California, mimeographed, 1966-?), vol. 5, ch. 18.

2. Oppenheimer's letter is in the Bancroft Library.

3. The ideas of the theoreticians, in truth not all too brilliant, but based on ideas then current, are reflected in their programmatic documents for the Rad Lab.

4. The documentation relative to this chapter is contained in my private archive. Among the documents there are several texts of agreements; letters narrating previous events in preparation for my first return to Italy in 1947; hundreds of letters by my brother Angelo; accounts of different kinds; and

a file relative to the events of 1953, including my correspondence with Marco concerning our father's will and its legal ramifications, as well as legal opinions. For my visit to Italy in 1947, there is a series of letters to Elfriede, almost constituting a diary. Correspondence with Riccardo Rimini in Uruguay, before and after the war, often reveals our most confidential feelings and opinions.

5. See G. Bordignon Favero, The Villa Emo at Fanzolo (University Park, Pa.: Pennsylvania State University Press, 1972).

1. For the general history of the Rad Lab in the postwar era, see J. L. Heilbron, Robert W. Seidel, and Bruce Wheaton, Lawrence and His Laboratory: Nuclear Science at Berkeley, 1931-1961 (Berkeley: Office for the History of Science and Technology, University of California, 1981), and a communication by Seidel in the Proceedings of the 1985 International Symposium on Particle Physics: Pions and Quarks held at Chicago in 1985. I learned of many of the events of those times from these sources. Only a small circle, to which I did not belong, was privy to Lawrence's activities. See also H. F. York, The Advisors: Oppenheimer, Teller and the Superbomb (San Francisco: W. H. Freeman, 1976) and Making Weapons, Talking Peace (New York: Basic Books, 1987).

2. See, e.g., Nucleon-Nucleon Scattering, ed. K. Nishimura (Physical Society of Japan, Selected Papers in Physics, n.s., no. 26).

3. This series of investigations starts with J. Hadley, E. L. Kelly, C. E. Leith, E. Segrè, C. Wiegand, and H. F. York, "Angular Distribution in n-p Scattering with 90-Mev Neutrons," Phys. Rev. 73 (1948): 1114-15, and extends up to 1957. A partial review is given in E. Segrè, "High Energy Scattering and Polarization," Physica 22 (1956): 1079-90.

4. H. Stapp, T. Ypsilantis, and N. Metropolis, "Phase Shift Analysis of 310 Mev p-p Scattering Experiments," Phys. Rev. 105 (1957): 302.

5. Experimental Nuclear Physics , ed. E. Segrè, with contributions by H. Staub; H. Bethe and J. Ashkin; N. F. Ramsey; K. T. Bainbridge; P. Morrison; B. T. Feld; E. Segrè; G. C. Hanna; M. Deutsch and O. Kofoed-Hansen; and E. M. McMillan (New York: Wiley, 1953-59).

6. See E. Segrè, "Preface," Ann. Rev. Nuclear Science 26 (1976): vii-x.

7. See E. Segrè, "High Energy Scattering of Neutrons and Protons," Helvetica Phys. Acta 23, supp. 3 (1950): 197-205.

8. See G. R. Stewart, The Year of the Oath (Garden City, N.Y.: Doubleday, 1950), and D. P. Gardner, The California Oath Controversy (Berkeley and Los Angeles: University of California Press, 1967), as well as R. T.

Birge, "History of the Physics Department" (University of California, Berkeley, 1966-?; 5 vols., mimeographed), vol. 5, ch. 19.

9. Pius XI, Per la azione cattolica (encyclical, June 29th 1931). See, e.g., A. C. Jemolo, Chiesa e stato in Italia negli ultimi 100 anni (Turin: Einaudi, 1949), p. 664.

10. See York, The Advisors, and Rhodes, Making of the Atomic Bomb .

11. S. A. Blumberg and Gwinn Owens, Energy and Conflict: The Life and Times of Edward Teller (New York: Putnam, 1976) gives Teller's version of these events. E. Segrè, Enrico Fermi, fisico, 2d ed. (Bologna: Zanichelli, 1987) supplies some documents newly made available.

12. E. Segrè, I nuovi elementi chimici: Chimica nucleare alle alte energie (The new chemical elements: Nuclear chemistry at high energies) (Rome: Acc. naz. Lincei, Fondazione Donegani, 1953).

13. E. Segrè, "Über den Zeemaneffekt von Quadrupollinien" (On the Zeeman effect of quadrupole lines), Zs. f. Physik 66 (1930): 827-29; partial review in E. Segrè, "L'irradiamento dei quadrupoli" (Quadrupole radiation), Nuovo cimento 2 (1931): 28-37.

14. E. Amaldi and E. Segrè, "Einige spektroskopische Eigenschaften hochangeregter Atome" (Some spectroscopic properties of highly excited atoms), in Zeeman Verhandelingen (The Hague: Martinus Nijhoff, 1935), pp. 8-17.

15. E. Segrè, "Artificial Radioactivity and the Completion of the Periodic System of the Elements," Scientific Monthly 57 (1943): 12-16; J. W. Kennedy, G. T. Seaborg, E. Segrè, and A. C. Wahl, "Properties of 94 ²³⁹ ," Phys. Rev. 70 (1946): 555-56; and G. T. Seaborg and E. Segrè, "The TransUranium Elements," Nature 159 (1947): 863-65.

16. E. Segrè, R. S. Halford, and G. T. Seaborg, "Chemical Separation of Nuclear Isomers," Phys. Rev. 55 (1938): 321-22.

17. E. Segrè, "Possibility of Altering the Decay Rate of a Radioactive Substance," Phys. Rev. 71 (1946): 274 (abstract).

18. Partial summary of the former in E. Segrè, "High Energy Scattering and Polarization" (cited n. 3 above); partial summary of the latter in E. Segrè, "Antinucleons: Richtmyer Lecture 1957," Am. Jour. of Physics 25 (1957): 363-69.

19. E. Fermi, E. Amaldi, O. D'Agostino, F. Rasetti, and E. Segrè, "Artificial Radioactivity Produced by Neutron Bombardment," Proc. Roy. Soc. (London) 146 (1934): 483-500; E. Fermi, E. Amaldi, O. D'Agostino, B. Pontecorvo, F. Rasetti, and E. Segrè, "Artificial Radioactivity Produced by Neutron Bombardment, II," ibid. 149 (1935): 552-58.

20. Lewis Strauss, a well-known American investment banker and a protégé of President Hoover's, suffered a similar failure. He attributes this to the fact that the leaders of U.S. industry then thought that nuclear energy was science fiction; see Strauss, Men and Decisions (Garden City, N.Y.:

Doubleday, 1962). And see also Lawrence Badash, Elizabeth Hodes, and Adolph Tiddens, "Nuclear Fission: Reaction to the Discovery in 1939," Proc. Am. Phil. Soc . 130 (1986): 196-231.

21. J. W. Mihelich, A. Schardt, and E. Segrè, "Energy Levels in Po ²¹⁰ ," Phys. Rev. 95 (1954): 1508-16.

22. C. L. Oxley, W. F. Cartwright, J. Rouvina, E. Baskir, D. Klein, J. Ring, and W. Skillman, "Double Scattering of High Energy Protons," Phys. Rev. 91 (1953): 419.

23. Enrico Fermi, "Polarization of High Energy Protons Scattered by Nuclei," Nuovo cimento 11 (1954): 417. FP267.

1. The translation is from Poems of Schiller (New York: John D. Williams, n.d.).

2. See Stanley A. Blumberg and Gwinn Owens, Energy and Conflict: The Life and Times of Edward Teller (New York: Putnam, 1976), p. 374, for Teller's account of his visit to Fermi following my message.

3. Enrico Fermi, Nuclear Physics, notes compiled by J. Orear, A. H. Rosenfeld, and R. A. Schluter (Chicago: University of Chicago Press, 1949). See also C. N. Yang, FP239, for the impression received on a visit to Fermi at the hospital.

4. Enrico Fermi, Collected Papers (Accademia dei Lincei and University of Chicago Press, 1961, 1965).

5.   I dream myself back to childhood
And shake my hoary head;
Why am I haunted by pictures
That I thought long ago to be dead?

High out of shady enclosures
A glistening castle looms large,
I know the embattled towers,
The stone bridge and also the gate.

From the escutcheon the lions are looking
Confidingly down at me
I greet these acquaintances gladly
And hurry across the court.
. . . . . . . . . .
Thus rises my ancestors' castle
Fixed loyally in my mind,
From the earth you have surely vanished,
The plow is traversing thy ground.
                                        trans. Egon Schwarz

6. O. Chamberlain, E. Segrè, C. Wiegand, and T. Ypsilantis, "Observation of Antiprotons," Phys. Rev. 100 (1955): 947-50, and "Antiprotons," Nature 177 (1956): 11-12.

7. O. Chamberlain and C. E. Wiegand, CERN Symposium on High Energy Accelerators and Pion Phys., Geneva, Proceedings , vol. 2 (1956), p. 52; C. E. Wiegand, Inst. Radio Eng., 6th Scintillation Counters Symposium, Proceedings (Washington, D.C., 1958).

8. E. Amaldi, G. Baroni, C. Castagnoli, O. Chamberlain, W. W. Chupp, C. Franzinetti, G. Goldhaber, A. Manfredini, E. Segrè, and C. Wiegand, "Antiproton Star Observed in Emulsions," Phys. Rev. 101 (1956): 909-910, and E. Amaldi, G. Baroni, C. Castagnoli, O. Chamberlain, W. W. Chupp, A. G. Ekspong, C. Franzinetti, G. Goldhaber, E. J. Lofgren, A. Manfredini, E. Segrè, and C. Wiegand, "Example of an Antiproton-Nucleon Annihilation," Phys. Rev. 102 (1956): 921-23.

9. On November 15 and 16, 1985, there was a small conference at Berkeley to commemorate the thirtieth aniversary of the antiproton's discovery. The first morning was devoted to history; L. W. Alvarez presided. He started with an introduction explaining why he had not discovered the antiproton and why the discovery was not trivial and obvious. Next Lofgren spoke, giving an excellent presentation on the bevatron. Clyde Wiegand followed for about thirty minutes. He gave a detailed account of the work performed by himself and Chamberlain. Among other things, he said that he and Chamberlain had started planning the experiment secretly, outside of regular working hours. He mentioned Ypsilantis only peripherally, in connection with the addition of a counter to the apparatus. He never mentioned me, as though I had not existed. I was saddened by the performance. It must represent Wiegand's present state of mind; this must be his recollection of the discovery of the antiproton.

Others spoke following Wiegand. Finally, Piccioni spoke for a few minutes on the antineutron discovery in which he had participated; then, for about an hour, he renewed his accusations against Chamberlain and me, saying that we had stolen the plans of the apparatus used from him, and that I had by trickery excluded him from the execution of the experiment. Part of the public smiled; others did not seem to enjoy the performance. A historian commented to me: "See why historians put more trust in documents than in possibly distorted memories?" To avoid further unseemliness, I did not reply to Piccioni.

10. See B. Cork, G. Lambertson, O. Piccioni, and W. Wenzel, "Antineutrons Produced from Antiprotons in Charge-Exchange Collisions," Phys Rev. 104 (1956): 1193-96; they used a counter method.

11. J. Button, T. Elioff, E. Segrè, H. M. Steiner, R. Weingart, C. Wiegand, and T. Ypsilantis, "Antineutron Production by Charge Exchange," Phys. Rev. 108 (1957): 1557-61, and L. Agnew, T. Elioff, W. B. Fowler, L.

Gilly, R. Lander, L. Oswald, W. Powell, E. Segrè, H. Steiner, H. White, C. Wiegand, and T. Ypsilantis, ''Antiproton-Proton Elastic and Charge Exchange Scattering at about 120 Mev," Phys. Rev. 110 (1958): 994-95.

12. See, e.g., L. W. Alvarez, in Les Prix Nobel en 1968 (Stockholm: Nobelstiftung, 1969).

13. L. B. Auerbach, T. Elioff, W. B. Johnson, J. Lach, C. Wiegand, and T. Ypsilantis, "Study of Pion-Pion Interactions from Pion Production by Pions," Phys. Rev. Letters 9 (1962): 173-76. G. Kallen, Elementary Particle Physics (Reading, Mass.: Addison-Wesley, 1964, p. 185), reports these experiments to have established the resonance, but in the end they could not compete with the bubble chamber.

14. Chemical and Engineering News 48 (1947): 3572. The poll asked respondents to name the ten ablest chemists working in several specialized fields. In nucleonics, the list was P. H. Abelson, C. D. Coryell, F. Daniels, Gerhart Friedländer, J. W. Kennedy, W. F. Libby, G. T. Seaborg, E. Segrè, N. Sugarman, and A. C. Wahl, in alphabetical order.

15. E. O. Lawrence, letter to Harold C. Urey, of May 31, 1946 (Bancroft Library). See pp. 167-68 above for the relevant excerpt. The letter in which Lawrence joined with Seaborg in proposing me for the Nobel Prize in 1959, based on the discovery of antiprotons, is also among the Lawrence Papers at the Bancroft Library.

16. Many students, some of the greatest ability, participated in our work. From the postwar period at Berkeley I remember Herbert York, John Jungerman, S. C. Wright, S. N. Ghoshal, E. L. Kelly, G. Temmer, M. O. Stern, A. Bloom, G. Pettengill, R. L. Mather, F. N. Spiess, T. J. Thompson, W. John, J. E. Simmons, D. V. Keller, Joe Lach, J. Foote, H. Ruggs, Rein Silberberg, H. Stubbs, R. C. Weingart, L. E. Agnew, T. Elioff, R. R. Larsen, J. Button, M. Jakobson, P. Kijewsky, W. Lee, E. H. Rogers, R. E. Hill, D. A. Jenkins, S. R. Kunselman, and Gary Lum. Many of them have had distinguished careers that can be traced in American Men of Science . Herbert Steiner, W. Chinowsky, Gerson Goldhaber, Tom Ypsilantis, and R. Tripp joined the Berkeley faculty. Rae Stiening, who came at a later date, from MIT, where he had studied with Martin Deutsch, infused new vitality into our work. To this list one should add several postdoctoral fellows: Jonas Schultz, Paul Condon, and from outside the United States, von Dardel, Gilly, N. Lipman, Borghini, G. Ekspong, R. Mermod, N. Booth, B. Mashhoon, and much later Min Chen.

17. R. B. Bacastow, T. Elioff, R. R. Larsen, C. Wiegand, and T. Ypsilantis, "Measurement of the Branching Ratio for Pion Beta Decay," Phys. Rev. Letters 9 (1962): 400.

18. See, e.g., R. Seki and C. Wiegand, "Kaonic and Other Exotic Atoms," Ann. Rev. Nucl. and Part. Science 25 (1975): 241.

19. See, e.g., Reminiscences about I. E. Tamm , ed. E. L. Feinberg (Moscow: Nauka Publishers, 1987).

20. See R. Marshak, "The Rochester Conferences," Bull. Atomic Scientists , June 1970, p. 72.

21. See, e.g., Les Prix Nobel en 1957 (Stockholm: Nobelstiftung, 1958). There is an extended literature on the discovery of the nonconservation of parity, including personal recollections by Lee, Wu, and Yang.

22. See E. Segrè, "Neue Atomarten und Antimaterie" (New atomic species and antimatter), Angew. Chemie 5 (1959): 173-76.

23. E. Segrè, Enrico Fermi, fisico (Bologna: Zanichelli, 1970, 1987).

24. Karl Manne Georg Siegbahn (1886-1978), winner of the 1924 Nobel Prize for physics, and his son Kai Manne Siegbahn (1918-), who won the physics prize in 1981.

25. See Les Prix Nobel en 1959 (Stockholm: Nobelstiftung, 1960).

26. E. Segrè, "From Atoms to Antiprotons" (Faculty Research Lecture, University of California, 1960, unpublished).

27. See, e.g., The Science of Materials Used in Advanced Technology , ed. E. Parker and U. Colombo (New York: Wiley, 1973).

28. E. Segrè, Nuclei and Particles (New York: W. Benjamin, 1964, 1977); also translated into Italian (Bologna: Zanichelli, 1966, 1982) and Chinese.

29. E. Segrè, "The Consequences of the Discovery of the Neutron," 10th Int. Conf. of the History of Science, Proceedings (Paris: Hermann, 1965), vol. 1, p. 149-58.