Baade, Shapley, and the Doubling of the Universe

Abstract

In his recent review of Donald E. Osterbrock’s book on Walter Baade (Physics Today, November 2002, page 69), Norriss S. Hetherington mentions “Harlow Shapley’s shameless attempt to claim credit for the doubling of the scale of the universe.”Perhaps a more nuanced interpretation of Shapley’s contribution to the cosmic distance scale problem is in order. The paper at issue is titled “Magellanic Clouds, VI. Revised Distances and Luminosities,” 1 1. H. Shapley, Proc. Nat Acad. Sci. USA 39, 349 (1953) https://doi.org/10.1073/pnas.39.5.349. and in it, Shapley redetermined the luminosities of globular-like clusters in the Magellanic Clouds. Assuming that such clusters are as luminous as galactic globular clusters, he found that the clouds are about twice as far away as had previously been believed. Shapley also pointed out in that paper that the noted increase in the distance of the clouds explains the “failure of the persistent Harvard searches for cluster-type cepheids in the Magellanic Clouds and their globular clusters.” Shapley specifically cited Baade’s similar failure to detect RR Lyrae variables at their expected luminosity level in the Andromeda galaxy; Baade’s results were reported at the International Astronomical Union’s meeting in Rome the previous year, 1952. Shapley cited Baade’s previous work three times in his paper.In a report on the astronomical highlights of 1952, Shapley placed Baade’s contribution first when he wrote about the “general acceptance of the growing evidence, produced chiefly at Mount Wilson—Palomar [that is, by Baade] and at Harvard [by Shapley], … that the distances of the Magellanic Clouds, the Andromeda nebula, and nearly all external galaxies must be appreciably increased.” 2 2. H. Shapley, Sky & Telescope, December 1952, p. 45. In retrospect, it seems likely that an overly enthusiastic New York Times article (4 January 1953, p. E8), based on Shapley’s report to the American Astronomical Society, may lie at the root of the apparent controversy over who deserves credit for the 1952 doubling of the distance scale in the universe.REFERENCESSection:ChooseTop of pageREFERENCES <<1. H. Shapley, Proc. Nat Acad. Sci. USA 39, 349 (1953) https://doi.org/10.1073/pnas.39.5.349. Google ScholarCrossref, CAS2. H. Shapley, Sky & Telescope, December 1952, p. 45. Google Scholar© 2003 American Institute of Physics.