The Strangest Man

by Graham Farmelo

  4 Dirac raised the issue of left–right symmetry in quantum mechanics in the Ph.D. examination of K. J. Le Couteur in 1948, see Dalitz and Peierls (1986: 159).

  5 On 25 August 1970, Dirac gave a piece of paper to the physicist Ivan Waller bearing the message: ‘The statement that I do not believe there is any need for P and T invariance occurs in Rev Mod Phys vol 21 p 393 (1949). I never followed it up. PAM Dirac.’ Waller archive, RSAS. See also Pais (1986: 25–6).

  6 Polkinghorne (1987: 229).

  7 Seven years later, in 1964, when two experimenters at Princeton University confirmed that some quantum processes that involve the weak interaction are not symmetric when time is reversed, most physicists were once again shocked. But not Dirac: he had also foreseen that possibility in the two paragraphs of his 1949 relativity paper.

  8 The ‘wrong horse’ quote is from a round-table discussion at the Fermilab Symposium in May 1980, Brown and Hoddeson (1983: 268). The ‘complete crushing’ quote is from Dirac’s talk at the Argonne Symposium on Spin, 26 July 1974, see ‘An Historical Perspective on Spin’ Lecture notes, pp. 3, Dirac Papers, 2/29/3 (FSU).

  9 Taubman (2003: 302).

  10 ‘The Soviet Crime in Hungary’, New Statesman, 10 November 1956, p. 574.

  11 Interview with Tam Dalyell, 9 January 2005. Dalyell recalls that his meeting with Dirac took place in either 1971 or 1972.

  12 Letter from Dirac to Kapitza, 29 November 1957, Dirac Papers, 2/4/12 (FSU).

  13 The connection with the anniversary was pointed out in the New Statesman in 26 October and 9 November 1957.

  14 Interview with Monica Dirac, 1 May 2006.

  15 Dirac often told his daughter Mary that he would like to travel to the Moon. Interview with Mary Dirac, 10 April 2006.

  16 Newhouse (1989: 118).

  17 Newhouse (1989: 118).

  18 The other two physicists at lunch with Dirac were Peter Landshoff and John Nuttall. Interview with Peter Landshoff, 6 April 2006.

  19 Letter from Dirac to Walter Kapryan, 19 July 1974, Dirac Papers, 2/7/6 (FSU).

  20 I thank Bob Parkinson and Doug Millard for their advice on the reasons why space rockets were launched vertically rather than horizontally.

  21 Interview with the Revd. Sir John Polkinghorne, 11 July 2003.

  22 Interview with the Revd. Sir John Polkinghorne, 11 July 2003. Dirac once asked ‘What is a rho meson?’, a particle then well known to almost all particle physics researchers.

  23 Interview with the Revd. Sir John Polkinghorne, 11 July 2003.

  24 Interview with Monica Dirac, 7 February 2003. In 1967, Dirac’s parking rights were further constrained, and, again, Manci was outraged. Letter from R. E. Macpherson to Dirac, 2 November 1967, Dirac Papers, 2/6/3 (FSU).

  25 Interview with John Crook, 1 May 2003.

  26 After the Christmas vacation of 1959, Gabriel urged his mother to stop telling Dirac ‘I will leave you’ in front of them. Letter from Gabriel to the Diracs, 13 January 1960, Dirac Papers, 1/8/12 (FSU).

  27 Interview with Stanley Deser, 5 July 2006.

  28 Letter to Dirac from Manci, 10 April 1954 (DDOCS).

  29 Interview with Monica Dirac, 7 February 2003.

  30 Hardy (1940: 87). See, for example, letters to Dirac from Gabriel, 22 September 1957 and 8 October 1957, property of Barbara Dirac-Svejstrup.

  31 Interview with Mary Dirac, 21 February 2003.

  32 Dirac told Gamow in 1961 that he began his work on general relativity in the hope of finding a connection between the theory and neutrinos, but that the project had failed. Letter from Dirac to Gamow, 10 January 1961, LC, Gamow archive.

  33 The word ‘graviton’ appears to have been used for the first time in print by the Soviet physicist D. I. Blokhintsev in the journal Under the Banner of Marxism (Pod znamenem marxisma): Blokhintsev (1934). See Gorelik and Frenkel (1994: 96).

  34 ‘Physicists Offer New Theories on Gravity Waves and Atomic Particles’, New York Times, 31 January 1959.

  35 Deser (2003). I am grateful to Sir Roger Penrose (interview 20 June 2006) and Stanley Deser (interview 5 July 2006) for advice on Dirac’s contribution to general relativity.

  36 Pais (1986: 23) and Salam (1987: 92).

  37 Dirac describes the theory in this way in the notes for the talk he gave on 8 October 1970, ‘Relativity Against Quantum Mechanics’, Dirac Papers, 2/28/19 (FSU). See also Dirac (1970).

  38 This description of Oppenheimer is based on the one given by Stephen Spender in Journals 1939–83. See also Bernstein (2004: 194).

  39 Anon. (2001: 109–34).

  40 Letter from Dirac to Margrethe Bohr, 20 November 1962, NBA. Margrethe’s reply, dated 19 December 1962, is in Dirac Papers, 2/5/9 (FSU).

  41 Nature, 4 February 1961, pp. 355–6; see p. 356.

  42 Interview with Dirac, AHQP, 1 April 1962, pp. 5–7.

  43 Interview with Dirac, AHQP, 1 April 1962, p. 5 (text from the original tape).

  44 Interview with Kurt Hofer, 21 February 2004.

  45 In my interviews with Leopold Halpern and Nandor Balázs, respectively on 18 February 2003 and 24 July 2002, they both noted that Dirac said he had ‘loathed’ his father – an extremely strong word for him to use.

  46 Letter from Kuhn to Dirac, 3 July 1962, Dirac Papers, 2/5/9 (FSU). Dirac subsequently gave four more interviews with Kuhn in 7 Cavendish Avenue, Cambridge, on 6, 7, 10 and 14 May 1963.

  47 Interview with Monica Dirac, 30 April 2006.

  Chapter twenty-seven

  1 Interview with the Revd. Sir John Polkinghorne, 11 July 2003.

  2 Interview with Mary Dirac, 21 February 2003.

  3 Dirac co-signed a letter, dated 27 April 1964, to Professor H. Davenport as part of a campaign to oust Batchelor from the headship of the Department of Applied Mathematics and Theoretical Physics, UCAM, Hoyle archive.

  4 Interview with Yorrick and Helaine Blumenfeld, 10 January 2004.

  5 Letter to Dirac from Oppenheimer, 21 April 1963, Dirac Papers, 2/5/10 (FSU).

  6 The Diracs were in the USA in 1962 and 1963 (based at the Institute for Advanced Study in Princeton until late April 1962 and from late September 1962 to early April 1963); in 1964 and 1965, based mainly at the Institute for Advanced Study, from September 1964 to spring 1965; in 1966 in March and April, based in Stony Brook, New York; in 1967, based in the spring at Stony Brook and November and December at the University of Texas at Austin; in 1968 and 1969, in December 1968 based in Stony Brook until after Christmas, when they moved on to the University of Miami, where they stayed until spring 1969.

  7 Goddard (1998: xiv).

  8 Dirac (1966: 8). One of the themes of these lectures is Dirac’s conclusion that the Schrödinger picture of quantum mechanics is untenable when it is applied to field theory and that only the Heisenberg picture is satisfactory.

  9 Dirac (1963:53).

  10 Several instances of Dirac’s declining to appear on BBC radio and television programmes are documented in Dirac’s archive at Florida State University, notably when he refused to be interviewed in connection with his Scientific American article (letter to Dirac from BBC radio producer David Edge, on 11 June 1963, Dirac Papers, 2/5/10 [FSU]).

  11 BBC Horizon programme ‘Lindau’, reference 72/2/5/6025. The recording was made on 28 June 1965 and broadcast on 11 August 1965.

  12 Barrow (2002: 105–12). Teller noted, however, that the experimental uncertainties in the calculations were so large that it was not possible definitely to rule out the hypothesis.

  13 Barrow (2002: 107).

  14 Letter from Dirac to Gamow, 10 January 1961, Gamow archive LC.

  15 Quoted in Barrow (2002: 108).

  16 Private papers of Mary Dirac. Dirac wrote the notes on 17 January 1933.

  17 Letter to Dirac from Gamow, 26 October 1957, Dirac Papers, 2/5/4 (FSU).

  18 John Douglas Cockcroft, Biographical Memoirs of Fellows of the Royal Society (1968): 139–88; see p. 185.

  19 Mitton (2005: 127–9).

  20 Overby
e (1991: 39).

  21 Letter from Gamow to Dirac, June 1965 (undated), Dirac Papers, 2/5/13 (FSU).

  22 Letter from Heisenberg to Dirac, 2 March 1967, Dirac Papers, 2/14/1 (FSU). Letter from Dirac to Heisenberg, 6 March 1967, quoted in Brown and Rechenberg (1987: 148).

  23 Letter from Geoffrey Harrison, HM Ambassador in Moscow, to Sir John Cockcroft, 19 April 1966, Cockcroft archive, CKFT 20/17 (CHURCHILL).

  24 Kapitza gave the lecture at 5 p.m. on Monday, 16 May. Source: Cambridge University Reporter, 27 April 1966, p. 1,649.

  25 Letter from Manci to Barbara Gamow, 12 May 1966, LC (Gamow archive). Other information from an interview with Mary Dirac, 21 February 2003.

  26 Letter from Manci to Rudolf Peierls, 8 July 1986, Peierls archive, additional papers, D23 (BOD).

  27 Boag et al. (1990: 43–4).

  28 Batelaan, H. (2007) Reviews of Modern Physics, 79, pp. 929–42.

  29 Dirac greatly admired Gell-Mann’s skills as a physicist but went out of his way to avoid him on social occasions. Source: interview with Leopold Halpern, 26 February 2006.

  30 Gell-Mann (1967: 699). For more examples of Gell-Mann’s initial scepticism about the reality of quarks, see Johnson (2000: Chapter 11).

  31 Gell-Mann (1967: 693).

  32 ‘Methods in Theoretical Physics’, 12 April 1967, Dirac Papers, 2/28/5 (FSU).

  33 Tkachenko was handed back to the Soviet Embassy on 18 September. The British authorities’ story was that Tkachenko had ‘freely expressed’ his wish to return to Russia, but privately they were fearful that he was going to die in their custody. See The Times, 18 June 1967, p. 1; New York Times, 16 September 1967, p. 1. See also the obituary of John Cockcroft by Kenneth McQuillen, former Vice-Master of Churchill College. I thank Mark Goldie, a Fellow of the college, for providing me with this anecdote.

  34 E-mail from Chris Cockcroft, 17 May 2007. See also Oakes (2000: 82). The anecdotes were confirmed by Mary and Monica Dirac.

  35 Letter from Wigner to Office of International Affairs, 1 September 1965, PRINCETON, Wigner archive.

  36 See, for example, letter from Wigner to Manci, 2 September 1965 (FSU, Wigner letters, annex to Dirac Papers).

  37 Letters from the Wigners, 6 and 13 May, and 14 September 1968 (FSU, Wigner letters, annex to Dirac Papers).

  38 Letter from Manci to Wigner, 10 February 1968, Wigner archive (Margit Dirac file) PRINCETON.

  39 Telegram 17 September 1968 (FSU, Wigner letters, annex to Dirac Papers); interview with Mary Dirac, 26 February 2006.

  40 Interview with Mary Dirac, 26 February 2006.

  41 Letter from Mary Wigner to the Diracs, 7 October 1968, Dirac Papers, 2/6/6 (FSU).

  42 Letters from the Wigners to the Diracs, 20 and 25 September and 9 October 1968 (FSU, Wigner letters, annex to Dirac Papers). Interview with Mary Dirac, 26 February 2006 and e-mail 7 June 2006.

  43 Interview with Mary Dirac, 26 February 2006 and e-mail 7 June 2006.

  44 Interview with Helaine and Yorrick Blumenfeld, 10 January 2004.

  45 Interview with Philip Mannheim, 8 June 2006. See also the article on Kursunoglu, ‘The Launching of La Belle Epoque of High Energy Physics and Cosmology’ in Curtright et al. (2004: 427–46).

  46 An account of Dirac’s time at the University of Miami is given by Kursunoglu’s wife in Kursunoglu and Wigner (1987: 9–28).

  47 Manci wrote to Gamow’s wife on 4 February 1969 to complain that Dirac had not accepted the offer made by the University of Miami: ‘It makes me feel awful’ (LC, Gamow archive, Manci Dirac file).

  48 The reaction of Rabbit and Janice Angstrom to 2001 are in Rabbit Redux, 1971, Chapter 1 (in the Fawcett Crest Book paperback edition, pp. 58 and 74).

  49 LoBrutto (1997: 277).

  50 I am grateful to Tony Colleraine, then Mary’s husband, for his recollections of Dirac’s first visits to see 2001: A Space Odyssey, interview 15 July 2004 and e-mails on 26 September and 22 October 2004.

  51 Interview with Monica Dirac, 7 February 2003.

  52 Letter from Manci to Barbara Gamow, 16 March 1971, Gamow archive LC.

  53 Letter from Manci to Wigner, 10 February 1968, PRINCETON, Wigner archive.

  54 These FBI documents were declassified in 1986. I thank Bob Ketchum for obtaining a copy of these documents under Freedom of Information/Privacy Acts.

  55 Letter from Dirac to Alfred Shild, 29 August 1966 (copy held by Lane Hughston).

  56 See, for example, the letter from the Senior Secretary at the University of Texas at Austin to the Immigration and Naturalization Service, 8 December 1967, part of the CIA file on Dirac in the 1960s and 1970s. I am grateful to Robert Ketchum for obtaining these documents.

  57 Tebeau (1976: 151–71 and 219–35). Stanford (1987: 54–5). Interview with Henry King Stanford, 3 July 2006.

  58 Wicker (1990).

  59 Letter from Wigner to Manci Dirac, 9 October 1968 (FSU, Wigner letters, annex to Dirac Papers).

  60 Miami Herald, 7 May 1970, p. 1.

  61 According to Morris (1972), the population of Tallahassee in 1970 was 72,000. The total population of Miami in the same year was 335,000.

  62 The Physics Department at Florida State University had recently obtained a Center of Excellence grant from the National Science Foundation to assist in its aspiration to become such a centre.

  63 Letter from Colleraine to Dirac, 2 February 1970, Dirac Papers, 2/6/9 (FSU).

  64 Tallahassee Democrat, 29 November 1970.

  65 Interview with Peter Tilley, 2 August 2005; interview with Leopold Halpern, 26 February 2006.

  66 Letter from Norman Heydenburg (Chair of the FSU physics department) to Dirac, 4 January 1971, Dirac Papers, 2/6/11 (FSU).

  67 Interview with Helaine and Yorrick Blumenthal, 10 January 2004.

  Chapter twenty-eight

  1 Press release from Dorothy Turner Holcomb, ‘Barbara Walters… I needed you!’, 9 March 1971, Dirac Papers, 2/6/11 (FSU).

  2 Walters (1970: 173).

  3 Notes on ‘The Evolution of our Understanding of Nature’, 8 March 1971, in Dirac Papers, 2/28/21 (FSU).

  4 Between 1969 and 1983, Dirac gave about a hundred and forty talks, an average of ten talks a year. He gave about eighty-eight talks in the USA, and fifty-two talks overseas, mainly in Europe but occasionally further afield, notably in Australia and New Zealand in 1975. See Dirac Papers, 2/52/8 (FSU).

  5 Interview with Kurt Hofer, 21 February 2004.

  6 Interview with Pam Houmère, 25 February 2003.

  7 E-mail from Hans Plendl, 5 March 2008, and another from Bill Moulton, 5 March 2008.

  8 Interview with Kurt Hofer, 21 February 2004. Hofer recalls that Dirac would melt when he realised that the person he had dismissed was a friend.

  9 Interview with Hofer. Leopold Halpern independently confirmed this description of Dirac’s telephone manner.

  10 Pais (1997: 211). Many of Dirac’s colleagues at Florida State University, including Steve Edwards (interview, 27 February 2004) and Michael Kasha (interview, 18 February 2003), attest to the enjoyment he took in telling this joke.

  11 M. Dirac (2003: 39).

  12 Interview with Barbara Dirac-Svejstrup, 5 May 2003.

  13 Letter from Manci to Dirac, undated, August 1972, Dirac Papers, 2/7/2 (FSU).

  14 Letter from Manci to Dirac, 18 August 1972, Dirac Papers, 2/7/2 (FSU).

  15 Interview with Ken van Assenderp, 25 February 2003.

  16 Interview with Helaine and Yorrick Blumenfeld, 10 January 2004. Helaine Blumenfeld recalls: ‘When I was pregnant with my second son, Manci called me all the time to check on things.’ Shortly before one of Mrs Blumenfeld’s appointments up at Addenbrooke’s Hospital, Manci advised her, ‘Well, you know they have a lot of black doctors there. Don’t let them touch you, they’re all dirty.’ Monica Dirac recalls that her mother was ‘the most anti-Semitic person I’ve ever met’, quite surprising as Manci herself was Jewish. Monica learned of her Jewish ancestry when she was twenty-one years old. Interviews with Monica Dir
ac, 7 February 2003 and 3 May 2006.

  17 Interview with Yorrick and Helaine Blumenfeld, 10 January 2004.

  18 Interview with Lily Harish-Chandra, 12 July 2007.

  19 Quoted in Chandrasekhar (1987: 65).

  20 The clearest account of Dirac’s research agenda during his later years is in the summary he wrote for Joe Lannutti in November 1974, Dirac Papers, 2/7/9 (FSU).

  21 Halpern (2003: 25). Interview with Leopold Halpern, 18 February 2003.

  22 Halpern (2003: 24–5).

  23 Leopold Halpern took me on this same trip on Sunday 26 February 2006. During this trip, and in earlier interviews, he described their trips down the river and their reception at home by Manci. In a separate interview, on 27 February 2004, Steve Edwards described the infamous incident in which Dirac dumped Kursunoglu in the Wakulla River

  24 Weinberg (2002).

  25 The special type of gauge theory, was first written down by Yang and his collaborator Robert Mills in 1954. Yang has described the theory as ‘a rather straightforward generalization of Maxwell’s equation’ (quoted in Woolf 1980: 502).

  26 Crease and Mann (1986: Chapter 16).

  27 In the late 1970s Dirac erroneously analysed the opacity of the universe and his error involved a misunderstanding of the Kapitza–Dirac effect (e-mail from Martin Rees, 27 November 2006). Another error is noted in Dalitz and Peierls (1986: 175).

  28 Interview with Leopold Halpern, 18 February 2002. Halpern recalled that Dirac took the discovery seriously and wanted to understand it. ‘How can you explain this portrait of Jesus? How can this happen?’ Dirac said several times. (The shroud was later proved to be a fake.)

  29 There is no record of Dirac’s taking any interest at all in the modern theory of renormalisation. He did, however, acknowledge the brilliance of physicists who worked on the theory, including Abdus Salam, Gerhard ’t Hooft and Edward Witten, whom he nominated for awards. Evidence of these nominations is in the Tallahassee archive.

  30 Interview with Rechenberg, 3 June 2003.

  31 Dirac (1977).

  32 Brown and Hoddeson (1983: 266–8).

  33 Interview with Lederman, 18 June 2002.

  34 Interview with Lederman, 18 June 2002. See Farmelo (2002b: 48). Einstein came close to predicting the existence of the positron in his 1925 paper ‘Electron and General Relativity’, see Fölsing (1997: 563–5).