1. The missionary zeal is described by J. L. Heilbron, “The earliest missionaries of the Copenhagen spirit,” Revue d’histoire des sciences , 38 (1985), 195-230, and in Science in reflection , Edna Ullmann-Margalit, ed., Boston studies in the philosophy of science, 110 (Dordrecht: Kluwer Academic Publishers, 1988), pp. 201-233. The predominance of this interpretation is explored in James T. Cushing, “Copenhagen hegemony: Need it be so?” manuscript.
2. WH to Pauli, 16 May 1927.
3. Bohr to Einstein, 13 Apr 1927 (BCW 6, 418-421).
4. Bohr, “The quantum postulate and the recent development of atomic theory,” in Atti del Congresso Internazionale dei Fisici 11-20 Settembre 1927,
Como-Pavia-Roma, vol. 2 (Bologna, 1928), pp. 565-588, on p. 569 (BCW 6, 113-136).
5. Ibid., p. 572. Bohr’s Como lecture and complementarity are further discussed in Jammer, Philosophy, pp. 86-101; and in Gerald Holton, “The roots of complementarity” (1970), in Holton, Thematic origins of scientific thought: Kepler to Einstein, rev. ed. (Cambridge, Mass.: Harvard University Press, 1988), pp. 99-145.
6. “Discussione sulla comunicazione Bohr,” note 4, Atti, pp. 589-598, on p. 593 (BCW 6, 137-146).
7. WH, “Die Entwicklung der Quantentheorie 1918-1928” (1929), HCW B, 109-115, on 114.
8. WH to Bohr, 23 Jul 1928 (BSC 11, 2).
9. WH to Bohr, 21 Aug 1927 (BPC).
10. Pauli to Bohr, 17 Oct 1927. Pauli’s rallying to the cause is described in Hendry, Creation.
11. Born, comment in “Discussione,” note 6, p. 589.
12. Born and WH, “La mecanique des quanta,” in Electrons et photons. Rapports et discussions du 5. Conseil de Physique . . . Solvay, ed. Institut International de Physique Solvay (Paris, 1928), pp. 143-181, on p. 143 (HCW B, 58-96).
13. Ibid., p. 178, their italics. The theory of radiation is the theory of the interaction of light with matter.
14. Pauli to Kramers, 27 Jul 25.
592 Notes
15. See J. Mehra, The Solvay conferences on physics: Aspects of the development of physics since 1911 (Dordrecht: D. Reidel Publishing Company, 1975).
16. Arthur Fine, The shaky game: Einstein, realism, and the quantum theory (Chicago: University of Chicago Press, 1986); Jammer, Philosophy, pp. 108-158; Pais, Subtle, pp. 440-449; Edward MacKinnon, Scientific explanation and atomic physics (Chicago: University of Chicago Press, 1982); Bohr, “Discussion with Einstein on epistemological problems in atomic physics,” in Albert Einstein: Philosopher-scientist, ed. P. A. Schilpp, vol. 1 (La Salle, Ill.: Open Court, 1949), 199-241.
17. Einstein to Born, 4 Dec 1926 (EB, Briefw.).
18. Given by Einstein in a discussion remark in Electrons et photons, note 12, pp. 253-256 (BCW 6, 101-103).
19. Bohr, note 16, “Discussion with Einstein,” pp. 212-216.
20. Einstein to Sommerfeld, 9 Nov 1927 (ES, Briefw.): also Einstein to Lorentz, 21 Nov 1927 (EA). Einstein offered another thought experiment at the sixth Solvay Congress in 1930 that concerned the uncertainty relation for energy and time.
21. Pauli to Weyl, 11 Jul 1929. Einstein’s and Bohr’s differing views are further discussed in the works cited in note 16.
22. WH to his parents, Brussels, 29 Oct 1927.
23. This has been argued in Paul Forman, “ Kausalitat, Anschaulichkeit, and Individuality, or How cultural values prescribed the character and the lessons ascribed to quantum mechanics,” in Society and knowledge: Contemporary perspectives in the sociology of knowledge, ed. Nico Stehr and Volker Meja (New Brunswick, N.J.: Transaction Books, 1984), pp. 333-347.
24. See WH, Bibl.
25. These are all reprinted in HCW, Cl.
26. Forman, note 23, attributes this to the German cultural milieu.
27. Born, ZP, 37 (1926), 863-867.
28. Born, note 11.
29. WH, “Erkenntnistheoretische Probleme der modernen Physik,” manuscript (HA), HCW, Cl, 22-28, on 28. This paper and Heisenberg’s overall philosophical position have been analyzed by Patrick A. Heelan, Quantum mechanics and objectivity: A study of the physical philosophy of Werner Heisenberg (The Hague: Martinus Nijhoff, 1965).
30. WH, “Die Rolle der Unbestimmtheitsrelationen . . .” (1931), HCW Cl, 40-47, on 45.
31. WH, “Kausalgesetz und Quantenmechanik” (1931), HCW Cl, 29-39, on 29-31.
33. WH, “Probleme der modernen Physik” (1932), HCW Cl, 48-49, on 49.
34. Heisenberg-Schlick correspondence, 1930-1932 (Schlick Papers, Amsterdam). I am grateful to Anne Kox for informing me of this correspondence.
35. WH, “Probleme,” note 33, p. 49.
36. Bohr’s papers on complementarity are published in BCW 6.
37. Heisenberg recalled these conversations in WH, PB, pp. 117-124.
38. Interview with C. F. von Weizsacker, 30 Apr 1982.
39. K. F. von Weizsacker, Ortsbestimmung eines Elektrons durch ein Mikroskoo ” ZP, 70 (1931), 114-130.
40. Quoted by Fine, note 16, p. 34.
41. Einstein, Podolsky, and Rosen, PR, 47 (1935), 777-780; reprinted in Wheeler and Zurek, eds., Quantum Theory and Measurement (Princeton: Princeton University Press, 1983), pp. 138-141. Fine, note 16, argues for Podolosky’s authorship.
42. Pauli to WH, 15 Jun 1935.
43. Further historical and philosophical discussions, from which this section has benefited, include Jammer, Philosophy, pp. 159-251; MacKinnon, note 16, pp. 338-348; and Fine, note 16.
44. The problem of disturbance is especially emphasized in Fine, note 16.
45. Quoted in Jammer, Philosophy, pp. 189-190.
46. Pauli to WH, 15 Jun 1935.
47. WH, “1st eine deterministische Erganzung der Quantenmechanik moglich?” manuscript enclosed in WH to Pauli, 2 Jul 1935 (PWB, vol. 2, pp. 409-418; another copy in EA). Heisenberg must have sent the manuscript to Einstein via an indirect route. He could not correspond directly with Einstein from Germany in 1935, and Heisenberg did not travel abroad in those months.
48. Bohr to WH, 2 Jul 1935 (BSC 20, 2), enclosing manuscript of Bohr, “Can quantum-mechanical description of physical reality be considered complete?” PR, 48 (1935), 696-702 (Wheeler and Zurek, note 41, 145-151).
49. WH to Bohr, 28 Aug 1935; Bohr to WH, 10 and 15 Sep 1935; and WH to Bohr, 29 Sep 1935 (BSC 20, 2).
50. WH, note 47, p. 417. Heisenberg referred to G. Hermann, Die naturphilosophischen Grundlagen der Quantenmechanik (Berlin, 1935). Hermann’s views, expounded before the EPR argument, and Heisenberg’s later use of them are discussed in Jammer, Philosophy, pp. 207-211.
51. WH, “Prinzipielle Fragen der modernen Physik,” delivered at University of Vienna, 27 Nov 1935 (HCW Cl, 108-119).
52. This is emphasized especially by MacKinnon, note 16, p. 344.
53. Bohr, note 48, “Description,” p. 702.
54. WH, note 51, p. 117.
55. WH, note 47, p. 410.
56. Einstein, “Remarks concerning the essays brought together in this co-operative volume,” in Schilpp, ed., note 16, vol. 2, pp. 665-688, on pp. 666-667, his parenthetical remarks.
57. WH, Physics and philosophy: The revolution in modem science (New York: Harper & Row, 1958), pp. 144 and 129.
58. “Come of age” attributed to physicist J. H. Van Vleck, by K. R. Sopka, Quantum physics in America 1920-1935 (New York: Arno Press, 1980), p. xiii.
59. This was argued in J. L. Heilbron, “La fisica negli Stati Uniti subito prima della meccanica quantistica,” in Fisici e societa negli anni ’20 (Milan, 1980), pp. 135-158; and Robert Seidel, “Aspetti istituzionali della transmissione della meccanica quantistica agli Stati Uniti,” in Fisici e societa negli anni ’20 (Milan, 1980), pp. 189-214. Critiques of these assertions and of alternative and traditional views of the later rise of American quantum theory are offered, among others, in Sopka, note 58; in Albert E. Moyer, “History of Physics,” Osiris, 1 (1985), 163-182; and in Holton, “On the hesitant rise of quantum physics research in the United States,” in Holton, note 5, Thematic, pp. 147-187. Philanthropic support of American science is examined in Robert E. Kohler, “Science, foundations, and American universities in the 1920s,” Osiris, 3 (1987), 135-164. The rise of American theoretical physics is explored in S. S. Schweber, “The empiricist temper regnant: Theoretical physics in the United States 1920-1950,” HSPS, 17 (1986), 55-98.
60. Schweber, note 59. However, geographic dispersion and disinterest among administrators slowed the development of American quantum physics research.
61. K. T. Compton, Nature, 139 (1937), 238-239.
594 Notes
62. List of past and future invited physicists, locations, salaries, and lengths of stay in H. M. Randall to W. F. G. Swann, 19 Feb 1929 (Swann Papers, Am. Philos. Society, Philadelphia).
63. The salaries ranged from $1500 for Hund to $6000 for Heisenberg. By comparison, the annual salary offered Heisenberg a year earlier to teach full time at Columbia University was $10,000. These were all large sums at the time.
64. Unfortunately, such contacts were not as helpful as they might have been.
65. AS, Atombau und Spektrallinien: Wellenmechanischer Erganzungsband (Braunschweig: Springer-Verlag, 1929).
66. WH to Sommerfeld, 6 Feb 1929 (AHQP 83, H).
67. WH to Bohr, 1 Mar 1929 (BSC 11, 2).
68. WH to Bohr, Chicago, 16 Jun 1929 (BSC 11, 2).
69. WH to Pauli, 20 Jul 1929. Heisenberg’s and Dirac’s travels are described in detail by L. Brown and H. Rechenberg, “Paul Dirac and Werner Heisenberg—a partnership in science,” in Reminiscences about a great physicist: Paul Adrian Maurice Dirac, ed. B. N. Kursunoglu and E. P. Wigner, (Cambridge: Cambridge University Press, 1987), pp. 117-162.
70. WH, The physical principles of the quantum theory, trans. C. Eckart and F. C. Hoyt (Chicago: University of Chicago Press, 1930), p. x (HCW B, 117-166).
71. Sommerfeld, note 65; Bom and Jordan, Elementare Quantenmechanik (Berlin: Springer-Verlag, 1930; Pauli, “Die allgemeinen Prinzipien der Wellenmechanik,” in Handbuch der Physik, 2nd ed., vol. 24, part 1 (Berlin, 1933), pp. 83-272. Section Al, pp. 83-90, is entitled “Unbestimmtheitsprinzip und Komplementaritat.”
72. A brief list of such textbooks is provided in Jammer, Philosophy, p. 59.
73. For instance, E. C. Kemble, The fundamental principles of quantum mechanics (New York: McGraw-Hill, 1937), p. 5, written after EPR. Kemble’s response to quantum theory is discussed in Holton, note 59.
74. I am grateful to Prof. S. S. Schweber for informing me of this recollection.