22 Letter from Manci to Dirac to ‘Anna’, 15 October 1986, Wigner archive in PRINCETON.
23 ‘Mrs Roosevelt’s Village Hall Lunch’, Cambridge Daily News, 5 November 1942.
24 Wattenberg (1984).
25 Interview with Al Wattenburg, 30 October 1992.
26 One of their meetings probably occurred on 31 July 1943, as Dirac proposes this date for a meeting in his letter to Fuchs of 19 August 1943 (BOD). Dirac wrote another letter to Fuchs on 1 September 1943 (BOD).
27 Peierls (1985: 163–4).
28 Szasz (1992: xix and 148–51).
29 Gowing (1964: 261).
30 Peierls, ‘Address to Dirac Memorial Meeting, Cambridge’, in Taylor (1987: 37).
31 Brown (1997: 250).
32 A further seventy people in Cambridge had been injured and 1,271 homes in the town had been damaged (Barham 1977: 53).
33 ‘Cambridge Streets Light-Up at Last!’, Cambridge Daily News, 26 September 1944.
34 Joe wrote of his family’s ‘threatening situation’ to Heisenberg on 25 March 1943 and sought his assistance. Four months later, Heisenberg replied to say that he was not able to offer specific help but hoped to make contact with Joe during a later visit to Holland (this meeting does not seem to have taken place). Joe wrote again to Heisenberg on 2 February 1944 from Budapest urgently requesting confirmation of Betty’s Aryan descent. See Brown and Rechenberg (1987: 156).
35 Letter from Betty to Dirac, 20 July 1946, Dirac Papers, 1/7/2A (FSU).
36 Interview with Mary Dirac, 21 February 2003.
37 Gabriel later recalled that Dirac declared that there ‘was no God and no Heaven or Hell’. Letter from Gabriel Dirac to the Diracs, 18 January 1972, Dirac Papers, 1/8/14 (FSU).
38 E-mail from Mary Dirac, 17 February 2006. Monica confirms that both daughters were christened.
39 Boys Smith (1983: 44).
40 Letter from Lew Kowarski to James Chadwick, 12 April 1943 (CHURCHILL).
41 Interview with the late John Crook, 1 May 2003. Professor Crook was present when Dirac made this remark.
42 ‘Happy Crowds Celebrate VE-Day’, Cambridge Daily News, 9 May 1945.
43 Interview with Monica Dirac, 1 May 2006.
44 Pincher (1948: 111). The account of this event by Chapman Pincher implied that Dirac lied. Pincher remarks, ‘Dr PAM Dirac, one of the scientists involved, told me at the time that he was not then engaged on vital war research. But, as the British White Paper on atomic energy states, he had been helping the British atom-bomb project by theoretical investigations on chain reactions.’ Pincher had not allowed for Dirac’s literal-mindedness.
45 Brown (2005: 266).
46 Interview with Leopold Halpern, 26 February 2006. Dirac told Halpern that he was disappointed with the actions of the British Government and that he went on long solitary walks in order to cool his anger. Dirac heard of the refusal of his application for an exit visa from the Home Office official C. D. C. Robinson (letter to Dirac, 13 June 1945, Dirac Papers, 2/3/15 [FSU]). Two days later, Nevill Mott wrote to Dirac to inform him of the protests that would be made by the disappointed scientists. Mott makes it plain that he does not expect Dirac to be an active member of the protesting group (letter to Dirac from Mott, Dirac Papers, 2/3/15 [FSU]).
47 Letter from Manci Dirac to Crowther, 18 May 1945, SUSSEX.
48 Telegram from Joe Teszler to the Diracs, 1 July 1945, Dirac Papers, 1/7/5 (FSU).
49 Interview with Christine Teszler, 22 January 2004.
50 Letters from Joe Teszler to Manci, 19 July, 2 August, 23 August, 31 August, 6 September and 27 September 1945, Dirac Papers, 1/7/5 (FSU).
51 Cornwell (2003: 396).
52 The team playing at Lord’s was not an official Australian side, but was called ‘The Australian Services’ team.
53 Smith (1986: 478).
54 ‘How Cambridge Heard the Great Victory News’, Cambridge Daily News, 15 August 1945.
55 See, for example, Time, 20 August 1945, p. 35.
56 Cornwell (2003: 394–400).
57 Anon. (1993: 36).
58 Anon. (1993: 71).
59 Dalitz (1987a: 69–70). Also, interview with Dalitz, 9 April 2003.
60 Interview with Christine Teszler, 22 January 2004.
61 Letter from Betty to Dirac, 20 July 1946, Dirac Papers, 1/7/2A (FSU).
62 Brown (2005: 173).
63 Crowther (1970: 264).
64 The official report on the lecture is in the UKNATARCHI (Dirac Papers. BW83/2/257889).
Chapter twenty-four
1 Osgood (1951: 149, 208–11).
2 Interview with Feynman by Charles Weiner, 5 March 1966, 27 March 1966, AIP. Interview with Lew Kowarski by Charles Weiner, 3 May 1970, AIP.
3 The typed manuscript of Dirac’s talk is in the Mudd Library, PRINCETON.
4 In Feynman’s theory, the probability that a quantum such as an electron will make a transition from one point in space-time to another can be calculated from a mathematical expression related to the action involved in moving between the two points, summed over all possible routes between them.
5 Interview by Charles Weiner of Richard Feynman, 27 June 1966 (CALTECH). See also Feynman’s Nobel Lecture and Gleick (1992: 226) and its references.
6 Interview with Freeman Dyson, 27 June 2005. Dyson noted that Feynman made the point repeatedly.
7 Quoted by Oppenheimer in Smith and Weiner (1980: 269). Wigner was one of the examiners of Feynman’s Ph. D. thesis; the other was Wheeler. The oral examination was held on 3 June 1942, and the examiners’ report is held in the Mudd Library, PRINCETON.
8 See Kevles (1971: Chapter 12) and Schweber (1994: Section 3).
9 Schweber (1994: Chapter 4); Pais (1986: 450–1); Dyson (2005).
10 Lamb (1983: 326). ‘Radar Waves Find New Force in Atom’, New York Times, 21 September 1947.
11 Ito (1995: 171–82).
12 Feynman (1985: 8).
13 Dyson (1992: 306). Interview with Dyson, 27 June 2005. Dyson’s description of himself as a ‘big shot with a vengeance’ is in Schweber (1994: 550).
14 Dyson (2005: 48).
15 Dirac took no pleasure in abstract art or in Schönberg’s music and found neither beautiful.
16 ‘The Engineer and the Physicist’, 2 January 1980, Dirac Papers, 2/9/34 (FSU).
17 Dirac Papers, 2/29/34 (FSU).
18 Dirac Papers, 2/29/34 (FSU).
19 Dyson (2006: 216).
20 Letter from Manci to Wigner, 20 February 1949, PRINCETON.
21 Interview with Richard Eden, 14 May 2003.
22 M. Dirac (1987: 6).
23 M. Dirac (2003: 41).
24 I am grateful to the Salamans’ daughter Nina Wedderburn for supplying me with biographical information on her parents. Fen (1976: 375).
25 Gamow (1966: 122); Salaman and Salaman (1986: 69).
26 Interview with Monica Dirac, 7 February 2003.
27 Quoted in Hennesey (2006: 5).
28 It took centuries for women students to win equality with males at Cambridge University. The first women’s colleges in Cambridge, Girton and Newnham Colleges, were founded in 1869 and 1871 respectively. From 1881 women were allowed to sit tripos exams but they did not receive any formal qualifications from the university for passing them. From 1882, women’s results were published with the men’s, but on separate lists. In 1921, a report proposing full admission for women was defeated. Statutes allowing the admission of women to full membership of the university finally received Royal Assent in May 1948, and the first woman to graduate at Cambridge was the Queen Mother in the following October. Under this legislation, women students at Cambridge first graduated in January 1949.
29 Reasons for Heisenberg’s post-war depression are suggested by Cassidy (1992: 528).
30 R. Eden, unpublished memoirs, May 2003, p. 7a.
31 Dirac first met Heisenberg after the war in 1958. ‘Hero’ quote from interview with Antonio Zichichi, 2 October 2005.
32 Inte
rview with Monica Dirac, 7 February 2003.
33 Greenspan (2005: 253, 263–4). Dirac supported Heisenberg’s nomination, having remarked earlier that his election to a foreign membership of the Royal Society should take precedence over that of Pauli. Cockcroft writes to Dirac in his 15 February letter, ‘I agree that he [Heisenberg] is more eminent than Pauli,’ Dirac Papers, 2/4/7 (FSU).
34 Letter to Dirac from Douglas Hartree, 22 December 1947, Dirac Papers, 2/4/2 (FSU).
35 Letter to Dirac from Schrödinger, 18 May 1949, Dirac Papers, 2/4/4 (FSU).
36 Soon after Blackett won the prize in 1947, Dirac sent to him ‘heartiest congratulations’, remarking, ‘You ought to have had it long ago’: letter from Dirac to Blackett, 7 November 1948, Blackett archive, ROYSOC. Yet Dirac had not nominated him.
37 Dirac nominated Kapitza twice before 1953, on 16 January 1946 and 25 January 1950. It is clear from Dirac’s records that he later nominated Kapitza several times (RSAS).
38 Letter from Dirac to Kapitza, 4 November 1945, Dirac Papers, 2/4/12 (FSU); See also letter from Kapitza to Stalin, 13 October 1944, reproduced in Boag et al. (1990: 361–3).
39 Boag et al. (1990: 378).
40 Letter from Kapitza to Stalin, 10 March 1945, cited in Kojevnikov, A. (1991) Historical Studies in the Physical Sciences, 22, 1, pp. 131–64.
41 Letters from Kapitza to Stalin, 3 October 1945 and 25 November 1945, reprinted in Boag et al. (1990: 368–70, 372–8).
42 Letter to Dirac from Manci, 12 July 1949 (DDOCS).
43 Tallahassee Democrat, 29 November 1970.
44 Bird and Sherwin (2005: 332).
45 Sources of anecdotes: ‘young daughters scurrying’, interview with Freeman Dyson, 27 June 2005; ‘welcoming Einstein for Sunday tea’, interview with Monica Dirac, 7 February 2003, interview with Mary Dirac, 21 February 2003; the ‘early evening drinks parties’, one of the social rituals at the institute during Oppenheimer’s tenure as Director; ‘amateur lumberjacks’, interview with Morton White, 24 July 2004.
46 Interview with Freeman Dyson, 27 June 2005. E-mail from Dyson, 23 October 2006.
47 Interview with Louise Morse, 19 July 2006.
48 Dirac received several importunate letters from the maverick Austro-Hungarian experimenter Felix Ehrenhaft, who asserted that he had evidence for the existence of the magnetic monopole, Dirac Papers, 2/13/1 and 2/13/2 (FSU).
49 Letter from Pauli to Hans Bethe, 8 March 1949, Hermann et al. (1979).
50 The new theory made little impact, though it did interest scientists – including Dennis Gabor at Imperial College in London – who were studying electron beams in television sets. The correspondence between Dirac and Gabor (1951) is in the Gabor archive at Imperial College, London.
51 Dirac (1954).
52 Dirac (1954).
53 ‘The Ghost of the Ether’ was published in the Manchester Guardian article on 19 January 1952; the New York Times published ‘Briton Says Space Is Full of Ether’, 4 February 1952. In Dirac’s talk to the 1971 Lindau meeting (for former Nobel Prize winners), he said that the ether appeared not to be useful to quantum mechanics, though he did not rule out that the concept might one day be useful.
54 Jerome (2002: Chapter 12, 278–82).
55 Interview with Einstein’s acquaintance Gillett Griffen on 20 November 2005, and with Louise Morse on 19 July 2006. The anecdote about Einstein picking up cigarette butts and sniffing them is from Kahler, A. (1985), My Years of Friendship with Albert Einstein, IX, 4, p. 7.
Chapter twenty-five
1 The information in this section is mainly from interviews with Monica Dirac (7 and 8 February 2002) and Mary Dirac (21 February 2002 and 17 February 2006). See also M. Dirac (2003: 39–42). Information about Dirac and Betty from interview with Christine Teszler, 22 January 2004.
2 The boarding school was Beeston Hall School in West Runton, near Cromer. E-mail from Mary Dirac, 30 October 2006.
3 The Diracs often stayed at the Barkston Gardens Hotel, Kensington, for a week or two.
4 Interview with Mary Dirac, 21 February 2003.
5 Letter to Dirac from Manci, 5 September 1949 (DDOCS): ‘We can have a quiet weekend in London where the Folies Bergère is showing the full Paris show.’
6 Professor Driuzdustades appears in Russell’s 1954 short story ‘Zahatopolk’ (see Russell 1972: 82–110).
7 Manci and Monica often ate at the Koh-I-Noor restaurant in St John’s Street. Interview with Monica Dirac, 7 February 2003.
8 Dalitz (1987b: 17).
9 Interview with Monica Dirac, 7 February 2003.
10 Interview with Tony Colleraine, 15 July 2004.
11 Bird and Sherwin (2005: 463–5).
12 Letter from Dirac to Manci, undated, late March 1954 (DDOCS).
13 Szasz (1992: 95).
14 Letter from Dirac to Oppenheimer, 11 November 1949, LC Oppenheimer archive.
15 Szasz (1992: 86, 95).
16 Pais often told this story. See, for example, Pais (2000: 70).
17 It appears that Dirac was excluded from a conference as early as 1951 because of Manci’s Hungarian nationality. See interview with Lew Kowarski by Charles Weiner, 3 May 1970, AIP, pp. 203–4.
18 The documents concerning the petition, dated 23 March 1950, are in the Bernal Papers, KV 2/1813, UKNATARCHI.
19 McMillan (2005: 12, 199).
20 This letter, from Dirac to Oppenheimer on 17 April, does not appear to have survived. However, Ruth Barnett, of the Institute for Advanced Study, refers to it in her letter to Dirac of 28 April 1954, Dirac Papers, 2/4/10 (FSU).
21 McMillan (2005: 214).
22 Letter from Dirac to Oppenheimer, 24 April 1954, IAS Dirac archive.
23 ‘US-Barred Scientist “Not Red”’, Daily Express, 28 May 1954.
24 ‘US Study Visa Barred to Nobel Prize Physicist’, New York Times, 27 May 1954.
25 Letter to Dirac from Christopher Freeman, Secretary of the Society for Cultural Relations with the USSR, 26 April 1954, Dirac Papers, 2/16/9 (FSU).
26 Pais (1998: 33).
27 Letter from Wheeler, Walker Bleakney and Milton White to the New York Times, published in the newspaper on 3 June 1954.
28 The name of the woman is not known for certain. Interview with Monica Dirac, 7 February 2003.
29 Dirac Papers, 2/14/5 (FSU).
30 After the Diracs’ stay in Mahabaleshwar, they returned to the Tata Institute in Bombay until 15 December. The Diracs then moved on to Madras and, on 20 December, travelled to Bangalore, where they spent Christmas. On New Year’s Eve, they returned to Bombay and then travelled to the Indian Science Congress in Baroda on 5 January. Four days later, they travelled to Delhi and saw the Taj Mahal shortly afterwards. The Diracs were in Calcutta from 18 January to 23 January, before returning to Delhi for a few days and then, finally, back to the Tata Institute. They left India, sailing from Bombay, on 21 February 1955.
31 Interview with George Sudarshan, 15 February 2005. In 1955, Sudarshan was a research assistant at the Tata Institute.
32 Dirac’s enthusiastic acceptance of the invitation to give this talk in his letter to Dr Basu, 23 June 1954, Dirac Papers, 2/4/10 (FSU).
33 Manuscript of the talk, corrected by Dirac, is in Dirac Papers, 2/14/5 (FSU). In the published version of this presentation, many of Dirac’s finest touches are removed (Journal of Scientific and Industrial Research, Delhi, A14, pp. 153–65).
34 Salaman and Salaman (1996: 68).
35 Science and Culture, Volume 20, Number 8, pp. 380–1, see p. 380.
36 Perkovich (1999: 59). India became a nuclear power in 1974, eight years after Bhabha died in a plane crash.
37 Letter to Oppenheimer from G. M. Shrum, 4 April 1955 (Oppenheimer archive, Dirac Papers, LC). Dirac may have caught this form of jaundice, homologous serum hepatitis, from a contaminated needle during a medical examination in December 1954, Dirac Papers, 1/9/3 (FSU).
38 Note from Manci to Oppenheimer included in Dirac to Oppenheimer, 25 September 1954 (
LC, Oppenheimer archive, Dirac Papers).
39 The Diracs sailed into Vancouver on 16 April. Letters from Manci to Oppenheimer, 15 April 1955, 22 April 1955 and other undated letters written at about the same time (LC, Oppenheimer archive).
40 Manci often remarked on the one time she saw her husband cry. See, for example, Science News, 20 June 1981, p. 394.
41 Interview with Tony Colleraine, 22 July 2004.
42 Letter from Manci to Oppenheimer, 29 August 1955, Oppenheimer archive, Dirac Papers, LC.
43 Medical report on 28 March 1955, Dirac Papers, 1/9/3 (FSU).
44 The Diracs were in Princeton from 22 May to 30 June 1955, and they flew to Ottawa on 1 July.
45 Letter from Manci to Oppenheimer, 29 August 1955 (LC, Oppenheimer archive).
46 Interview with Jeffrey Goldstone, 2 May 2006.
47 Talk on ‘Electrons and the Vacuum’ by Dirac at the Lindau conference. The manuscript, annotated by Dirac (June 1956) is in Dirac Papers, 2/27/14 (FSU).
48 ‘Electrons and the Vacuum’, pp. 7–8.
49 Dirac spent much of this year working on the fourth edition of The Principles of Quantum Mechanics, which was published in the following year, 1957.
50 For an account of Kapitza’s activities between 1937–49 see Kojevnikov (2004: Chapters 5–8).
51 Taubman (2003: Chapter 11).
52 The quote is in a letter from Dirac to Bohr, undated, NBI. The lecture was plainly written after this visit.
53 Dorozynski (1965: 61).
54 Boag et al. (1990: 368). See also Knight (1993: Chapters 9 and 10).
55 Taubman (2003: 256).
56 Fitzpatrick (2005: 227).
57 Dorozynski (1965: 60–1).
58 Feinberg (1987: 185 and 197).
59 Weisskopf (1990: 194).
60 Dirac’s writing is still preserved on the blackboard.
61 Landau made this remark at a conference in Moscow in 1957. Interview with Sir Brian Pippard, 29 April 2004.
Chapter twenty-six
1 Enz (2002: 533).
2 Dirac probably heard the news through the grapevine in Cambridge before the news was published. One of the first accounts of the experiment was published in the Guardian on 17 January 1957.
3 Shanmugadhasan (1987: 56).
The Strangest Man Page 71