The Death of a Research Programme: Kapteyn and the Dutch Astronomical Community

See, respectively, Struve Otto , The universe (Cambridge, Mass., 1964), 157; Bok Bark , “Harlow Shapley and the discovery of the center of our galaxy”, in Neyman Jerzy (ed.), The heritage of Copernicus (Cambridge, Mass., 1974), 26; and Lindblad Bertil to van de Kamp Peter , quoted in van de Kamp Peter , “The galactocentric revolution, a reminiscent narrative”, Publications of the Astronomical Society of the Pacific [hereafter: PASP], lxxvii (1965), 325–35, p. 325.

See Hoskin Michael A. , “The ‘Great Debate’: What really happened”, Journal for the history of astronomy, viii (1976), 169–82; and Seeley Daniel and Berendzen Richard , “Astronomy's Great Debate”, Mercury, vii (1976), 67–71, 88.

Shapley Harlow and Curtis Heber D. , “The scale of the universe”, Bulletin of the National Research Council, ii (1921), 171–217. At the time, neither Shapley nor Curtis considered this a ‘debate’. See Bok , “Harlow Shapley”, 53–55; and Whitney C. , The discovery of our galaxy (New York, 1971), 214–15. Otto Struve first gave this symposium its rubric ‘the great debate’; see Struve Otto , “A historic debate about the universe”, Sky and telescope, xix (1960), 398, and Struve Otto and Zebergs V. , Astronomy of the twentieth century (New York, 1962), 416. As early as 1935, however, Edwin Hubble referred to this symposium as a “quasi-debate”; see Hubble E. P. , The realm of the nebulae (New Haven, 1935), 87–88.

To refer to the Milky Way system as a ‘galaxy’ during this period is an anachronism. Throughout this paper, I will generally defer to the historical terms ‘stellar model’, ‘stellar system’, ‘stellar universe’, or ‘sidereal universe’ in referring to models of the (Milky Way) galaxy.

Recently a brief overview of this conflict has been given in the excellent work by Berendzen Richard Hart Richard , and Seeley Daniel , Man discovers the galaxies (New York, 1976), part I.

For a general discussion of Shapley's discovery of the galactic centre, see Bok , “Harlow Shapley”, 26–61.

Shapley H. , “First paper: The general problem of clusters”, Contributions of the Mount Wilson Observatory [hereafter: Contr. Mt Wilson Obs.], no. 115 (1915), 213.

Shapley , “First paper”, 213–14. At the time, the distance problem was considered one of the two most significant problems in astronomy. The other concerned the nature of stellar evolution; see, for instance, Aitken Robert G. , “Recent progress in our knowledge of the universe”, Science, lviii (1915), 381–7.

Leavitt Henrietta S. , “1777 variables in the Magellanic Clouds”, Annals of the Harvard College Observatory, lx (1908), 106–7.

Leavitt Henrietta S. , “Periods of 25 variable stars in the Small Magellanic Cloud”. Circular of the Harvard College Observatory, no. 173 (1908), 1–3.

Hertzsprung Ejnar , “Ueber die raumliche Verteilung der Veranderlichen vom δ Cephei Typus”, Astronomische Nachrichten, cxcvi (1913), 201–10. Cf. Jeans James H. , “The new outlook in cosmogony”, Annals of the Smithsonian Institution (1927), 151–60.

Shapley to Hale , 14 November 1912; Hale to Shapley , 26 December 1912 (Hale Microfilm Collection of the Mount Wilson and Las Campanas Observatories, Pasadena, California). Shapley's position at the Observatory Wilson Mount , however, did not begin until 1 January 1914.

Shapley H. , Through rugged ways to the stars (New York, 1969), 41.

Shapley , Through rugged ways, 52.

Shapley H. , “Second paper: 1300 stars in the Hercules Cluster (M13)”, Contr. Mt Wilson Obs., no. 16 (1915), 307–8.

Shapley , “Second paper”, 308.

For a discussion of the contemporary conceptions of the sidereal universe at the time Shapley wrote his paper, see Plaskett John S. , “The sidereal universe”, Journal of the Royal Astronomical Society of Canada, ix (1915), 37–56.

For a good discussion of the growth of the ‘island universe’ controversy, see Fernie J. D. , “The historical quest for the nature of the spiral nebulae”, PASP, lxxxii (1970), 1189–230.

Hale to Kapteyn , 12 April 1915 (Hale Microfilm).

Shapley H. , “Sixth paper: On the determination of the distances of globular clusters”, Contr. Mt Wilson Obs., no. 151 (1917), 115–16.

The magnitude-distance relationship relates the absolute magnitude (M) of a star with its apparent magnitude (m) and its distance (r) in parsecs. Thus, M = m+5–5 log(r).

Although Cepheids eventually became a major tool in distance determination, Shapley only used Cepheids in about 10 per cent of the calculated distances to the clusters, since not all clusters contained easily measured variables. In addition he used other methods based on the apparent magnitudes of the brightest stars in clusters and on their angular diameter. See Shapley H. , “Seventh paper: The distances, distribution in space, and dimensions of 69 globular clusters”, Contr. Mt Wilson Obs., no. 152 (1917), 117–31.

Shapley , “Seventh paper”, 131–40). In 1909, the Swedish astronomer Bohlin Karl pointed out the asymmetrical distribution of the clusters in the hemisphere, suggesting that the centre of the galaxy lay in the direction of the Sagittarius star cloud: See Bohlin , Kungliga Svenska Vetenskapsakademiens handlingar, no. 10 (1909), 43.

Shapley H. , “Twelfth paper: Remarks on the arrangement of the sidereal universe”, Contr. Mt Wilson Obs., no. 157 (1918), 209–24.

Shapley , “Twelfth paper”, 209.

Most accounts have failed to treat this problem adequately; see Whitney , The discovery of our galaxy, 212, and Bok , “Harlow Shapley”, 44–52.

Bok Bart , “Harlow Shapley—cosmographer and humanitarian”, Sky and telescope, xliv (1972), 354–57.

See Baade Walter , Evolution of stars and galaxies, ed. by Payne-Gaposchkin Cecilia (Cambridge, 1963), 9; and Perrine C. D. , “The nature of globular clusters”, Observatory, xl (1917), 166–8.

Moreover , the groupings of the clusters around the galactic poles suggested to Shapley their dependence upon the larger system of stars. See Shapley , “Seventh paper”, 136–40; Shapley , “Twelfth paper”, 218–22; and Shapley H. , “Note on the explanation of the absence of globular clusters from the mid-galactic regions”, Observatory, xlii (1919), 82–84.

Shapley himself wasted no time in publishing his ideas and conclusions in other technical journals in order to spread the new dogma; see Shapley H. , “Globular clusters and the structure of the galactic system”, PASP, xxx (1918), 42–54.

Although it has been claimed that Curtis accepted the essential features of the Kapteyn universe, Curtis was impressed more by Kapteyn's methods than by Kapteyn's conclusions. See Berendzen Hart , and Seeley , Man discovers the galaxies , 39. Curtis himself made it clear that “while I am ready to worship Kapteyn's methods, in which he has been fifty years ahead of the times, I can not, as most astronomers do, fall down and worship all the results which have come out of this mathematical mill” (H. D. Curtis to Alter, 1 February 1922 (Allegheny Observatory Archives)). I am indebted to Smith Robert W. for this view and for bringing this quote to my attention.

For some of the best contemporary accounts of the development and controversy surrounding the ‘island universe’ theory, see the following: Very F. W. , “Are the white nebulae galaxies?”, Astronomische Nachrichten, clxxxix (1911), 441–54; Puiseaux P. , “Spiral nebulae”, Revue scientifique, 6 April 1912; Crommelin A. C. D. , “Are the spiral nebulae external galaxies?”, Scientia, xxi (1917), 365–76; Curtis Heber D. , “Modern theories of spiral nebulae”, Journal of the Washington Academy of Sciences, ix (1919), 217–27; Shapley H. , “On the existence of external galaxies”, PASP, xxxi (1919), 261–8; MacPherson H. , “The problem of island universe”, Observatory, xlii (1919), 329–34; and McLaughlin Dean B. , “The present position of the island universe theory of the spiral nebulae”, Popular astronomy, xxx (1922), 286–95, 327–39.

See van Maanen Adriaan , “Preliminary evidence of internal motion in the spiral nebula Messier 101”, Contr. Mt Wilson Obs., no. 118 (1916), 331–49; and idem, “Internal motions in a spiral nebulae”, Observatory, xxxix (1916), 514–15. For some independent corroborative evidence on this problem, see Jeans James H. , “Internal motions in spiral nebulae”, Observatory, xl (1917), 60–61. Van Maanen's classic diagrams of the rotation of spirals appeared in “Investigations on proper motions. Fourth paper: Internal motion in the spiral nebula Messier 51”, Contr. Mt Wilson Obs. , no. 213 (1923), 221–9; and “Investigations on proper motions. Fifth paper: Internal motion in the spiral nebula Messier 81”, Contr. Mt Wilson Obs., no. 214 (1923), 231–40.

See Crommelin A. C. D. , “The nature of spiral nebulae”, Journal of the British Astronomical Association, xxviii (1918), 177–9.

Slipher Vesto M. , “Spectroscopic observations of star clusters”, Popular astronomy, xxvi (1918), 8.

Baade , Evolution of stars and galaxies, 9. Shapley himself referred to the conservative ‘old boys’ as ‘patriarchs’; see Hoskin , “The ‘Great Debate’”, 172.

On only two occasions was Kapteyn's relationship with the Mount Wilson people marred. Once over a professional dispute with Adams Walter S. in 1917, in which Kapteyn resigned (temporarily) his formal relationship with the Observatory Wilson Mount , and later over Hale's disagreement with Kapteyn concerning the rôle of German scientists in the First World War. See, respectively, Adams to Kapteyn , 24 April 1917; Kapteyn to Hale , 26 June 1917; Hale to Kapteyn , 22 September 1917; Kapteyn to Hale , 18 November 1917, 3 December 1917, 31 August 1919; and Hale to de Sitter Willem , 10 February 1921 (Hale Microfilm).

Hale to de Sitter , quoted in de Sitter , “Nekrologe—Jacobus Cornelius Kapteyn”, Vierteljahrsschrift der Astronomische Gesellschaft, lviii (1923), 182.

Kapteyn to Hale , 7 February 1919 (Hale Microfilm).

Kapteyn to Hale , 3 January 1922 (Hale Microfilm).

The influence which Kapteyn exerted on his pupils, as well as on others, was enormous. van Rhijn Both and Schouten , who completed their dissertations under Kapteyn in 1915 and 1918 respectively, were among the ‘old boys’ referred to by Baade. Although they were roughly Shapley's age, both were in the forefront in defending Kapteyn's life-long project to solve the sidereal problem directly by the use of classical statistical methodology.

Schouten Willem J. A. , “On the parallax of some stellar clusters”, Koninklijke Akademie van Wetenschappen te Amsterdam. Proceedings of the section of sciences, xx (1918), 1108–18 (communicated 26 January 1918); idem, “On the parallax of some stellar clusters”, ibid., xxi (1919), 36–47 (communicated 23 February 1918). Also see his “The parallax of some stellar clusters”, Observatory, xlii (1919), 112–19 (communicated November 1918).

See Kapteyn J. C. , “On the individual parallaxes of the brighter galactic helium stars in the southern hemisphere, together with considerations on the parallax of stars in general”, Contr. Mt Wilson Obs., no. 82 (1914), 400–1.

Schouten , “On the parallax of some stellar clusters” (ref. 42), 36–47.

Pannekoek Anton , “The distance of the Milky Way”, Monthly notices of the Royal Astronomical Society, lxxix (1919), 500–7.

Easton Cornelius , “On the distance of the galactic star-clouds”, Monthly notices of the Royal Astronomical Society, lxxxi (1921), 215–26.

Kopff A. , “Die Untersuchungen H. Shapleys ueber Sternhaufen und Milchstrassensystem”, Die Naturwissenschaften, ix (1921), 769.

Shapley , “Sixth paper”, 81–116.

See Shapley H. , “Eighth paper: The luminosities and distances of 139 Cepheid variables”, Contr. Mt Wilson Obs., no. 153 (1917), 148–54, 160.

Kapteyn to Hale , 3 March 1920 (Hale Microfilm).

Kapteyn to Shapley , 4 March 1920 (Harlow Shapley Papers of the Harvard University Archives).

Kapteyn J. C. and van Rhijn P. , “The proper motions of δ Cephei stars and the distances of the globular clusters”, Bulletin of the Astronomical Institutes of the Netherlands, i (1922), 40–41.

Kapteyn and Van Rhijn , “The proper motions of δ Cephei stars”, 41.

Shapley H. , “Notes bearing on the distances of clusters”, Circulars of the Harvard College Observatory, no. 237 (1922), 9–10.

Kapteyn and Van Rhijn , “The proper motions of δ Cephei stars”, 41.

Kapteyn to Shapley , 15 June 1919 (Shapley Archives).

Shapley to Pannekoek , 28 February 1922; Shapley to van Rhijn , 26 March 1922; Shapley to Agassiz George R. , 20 March 1922 (Shapley Archives).

Shapley to Agassiz , 19 June 1922 (Shapley Archives).

Shapley to Doig Peter , 21 June 1922; Shapley to Lundmark Knut , 15 July 1922 (Shapley Archives).

Shapley to Lewis Isabel M. , 7 July 1922 (Shapley Archives).

Shapley to Doig , 21 June 1922 (Shapley Archives).

Shapley to Lewis , 7 July 1922; Shapley to Kienle Hans , 27 September 1922 (Shapley Archives).

Shapley to Lundmark , 15 July 1922 (Shapley Archives).

A revised version of Shapley's BAA talk appeared as “The galactic system”, Nature, cx (1922), 545–7, 578–81.

Kapteyn J. C. , “First attempt at a theory of the arrangement and motion of the sidereal system”, Astrophysical journal, lv (1922), 302–27, p. 321.

Struve Otto was an on-site observer at conferences where Seeliger was perceived and treated as the “Dean” of German astronomy; see Struve and Zebergs , Astronomy of the twentieth century, 39–40. Schouten , as Kapteyn's “wipping boy”, vehemently defended his mentor's particular approach to statistical astronomy over the analytical developments suggested by Seeliger and others. In his dissertation, On the determination of the principal laws of statistical astronomy (Amsterdam, 1918), Schouten spent nearly one-fourth of his entire work in a severe criticism of Seeliger's approach. For Seeliger's seasoned reply see “Untersuchungen ueber das Sternsystem”, Sitzungsberichte der Mathematisch-Physikalischen Klasse der K. Bayerischen Akademie der Wissenschaften zu München, 1 (1920), 94.

Shapley to Hale , 19 January 1918 (Hale Microfilm).

See Shapley to Kapteyn , 25 July 1918, and 19 December 1918 (Shapley Archives).

Schmeidler Felix to Paul Robert E. , 18 October 1978 (in author's possession).

Shapley to Kienle , 11 October 1922 (Shapley Archives).

Schmeidler to Paul , 18 October 1978.

Shapley to Kienle , 11 October 1922 (Shapley Archives).

Shapley , “The Magellanic Clouds”, in Problem der Astronomie: Festschrift für H. v. Seeliger (Berlin, 1924), 438–41. Shapley's distances to the Magellanic Clouds were confirmed independently by others at the time. See Wilson R. E. , “On the distance of the Large Magellanic Cloud”, Astronomical journal, xxxv (1924), 183–4; and Lundmark K. , “The distance of the Large Magellanic Cloud”, Observatory, xlvii (1924), 276–9.

Without a doubt, Seeliger's most prominent student was Schwarzschild Karl , who, prior to his untimely death in 1916, had made significant contributions to statistical astronomy. See Schwarzschild Karl Papers (American Institute of Physics).

Kienle was not alone among Seeliger's students to share his optimism for the newer views of Shapley's; see for instance, ten Bruggencate Paul , “Note on the structure of Shapley's larger galactic system”, Bulletin of the Astronomical Institutes of the Netherlands, iv (1928), 198–201; and idem, Sterhaufen: Ihr Bau, ihre Stellung zum Sternsystem und ihre Bedeutung für die Kosmologie (Berlin, 1927), part I.

Charlier C. V. L. , “Studies in stellar statistics—The distances and the distribution of the stars of the spectral type B”, Meddelanden Fran Lunds Astronomiska Observatorium, Serie II, no. 14 (1916) (see pp. 31, 104).

Charlier C. V. L. , “Stellar clusters and related celestial phenomena—Studies in stellar statistics”, ibid., no. 19 (1918) (see p. 41).

Charlier C. V. L. , “Stjarnrakningen pa Lunds observatorium och Vintergatans byggnad” (11 May 1920); also see Shapley and Curtis , “The scale of the universe”, 174.

Shapley to Agassiz , 19 June 1922 (Shapley Archives).

Kapteyn to Hale , 3 March 1920 (Hale Microfilm).

Abbott Charles G. to Hale , 18 February 1920; Shapley to Hale , 19 February 1920 (Hale Microfilm).

Shapley to Luyten Willem J. , 18 July 1922 (Shapley Archives).

Shapley to Hale , 12 September 1920 (Hale Microfilm).

Hale to Lowell Lawrence A. , 11 December 1920 (Hale Microfilm).

See Hubble Edwin P. , “Cepheids in spiral nebulae”, Observatory, xlviii (1925), 139–42; and idem, “Distances of the Andromeda Nebula”, Popular astronomy, xxxiii (1925), 143. In contrast, Van Maanen had earlier derived a distance to Andromeda of only 900 light years; see van Maanen A. , “The parallax of the Andromeda Nebula”, PASP, xxx (1918), 307. For his paper, Hubble shared the joint award of the $1,000 prize given for the most outstanding paper at the annual meeting of the American Astronomical Society. His conclusions, in the words of Shapley's mentor Russell H. N. , were accepted, “… thus bringing confirmation to the so-called island universe theory”. See “3rd Meeting of the AAS”, Popular astronomy, xxxiii (1925), 159. For a recent discussion of Hubble's work on distances to the spiral nebulae, see Berendzen Richard and Hoskin Michael , “Hubble's announcement of Cepheids in spiral nebulae”, Leaflet of the Astronomical Society of the Pacific, no. 504 (1971). It is interesting—and somewhat ironic—that Hubble used Shapley's modification of the period-luminosity constants for Cepheid variables to establish the island universe dimensions of the spirals; see Campbell W. W. , “Do we live in a spiral nebulae?”, Popular astronomy, xxxiv (1926), 174–81.

For examples of such smaller galactic systems within the larger Hubble universe, see Wirtz C. , “Die Spiralnebel und die Struktur des Raumes”, Scientia, xxxviii (1925), 303–14; and Curtis H. D. , “The unity of the universe”, Journal of the Royal Astronomical Society of Canada, xxii (1928), 399–412.