The Day We Found the Universe - Marcia Bartusiak [154]
121 too small to be discernible by ground-based telescopes: Space telescopes, specially designed to do parallax work, have extended distance measurements out farther.
122 30,000 light-years distant: Hertzsprung (1914), p. 204. Hertzsprung's estimate, when published in the German journal Astronomische Nachrichten in 1914, was first printed as a much reduced 3,000 light-years, which diminished the impact of his finding. It was a clumsy arithmetical error on Hertzsprung's part. That it was meant to be around 30,000 light-years (10,000 parsecs) is seen in a typed, unsigned note in which either Walter Adams or George Hale remarks that by an “ingenious argument” Hertzsprung has found the distance of the Magellanic Cloud “to be 10,000 parsecs—the greatest distance we have yet had occasion to mention.” But the published error may have contributed to the delay in recognizing that other galaxies reside outside the boundaries of the Milky Way. CA, Hale Papers, Box 2, Hale/Adams correspondence. See also Sandage (2004), p. 361.
122 demonstrated for the first time: Fernie (1969), p. 708.
122 “I had not thought of making the very pretty use”: Smith (1982), p. 72.
122 concluded that they were giant stars: Russell (1913).
122 arriving at 80,000 light-years: Smith (1982), p. 72.
123 “improved and extended”: Shapley (1918a), p. 108.
123 Shapley tried mightily to check with Leavitt on this question: Shapley was still concerned late in his project. “I notice that a great many of the hundreds of [variables in the Small Magellanic Cloud] are fainter. Does Miss Leavitt know if they have shorter periods[?] … The matter is of much importance, as you know, because of the relation between periods and brightness,” he wrote Pickering in 1917. (HUA, Shapley to Pickering, August 27, 1917.) Leavitt was then away on an extended vacation and could not provide an immediate answer.
123 “Routine stuff”: HUA, Russell to Shapley, November 26, 1920.
123 “This proposition scarcely needs proof”: Shapley (1914), p. 449.
123 “The whole line of reasoning … was brilliant”: Sandage (2004), p. 303.
124 “definite conclusions from these data cannot be safely made”: Bailey (1919), p. 250.
124 With the assistance of Edison Hoge, he took some three hundred photographs: Shapley (1918b), p. 156.
124 “the work on clusters goes on monotonously”: Gingerich (1975), p. 346.
124 Hale had convinced him to stay at his job: HUA, Shapley to Russell, July 22, 1918.
125 With the first hint of dawn in the east … settle any squabbles: Sandage (2004), pp. 181, 195.
125 “The most unwarranted fun of all comes from bugs”: HUA, Shapley to Oliver D. Kellogg, December 31, 1918.
125 “Another method is to read your thermometer”: Shapley (1969), p. 66.
125 His findings were published in scientific journals: For example, see H. Shapley (1924), pp. 436–39.
125 further rest and relaxation: HUA, Shapley to Russell, September 3, 1917.
125 some well-known star clusters within the Milky Way were at least 50,000 lightyears distant: Smith (2006), p. 319.
126 “This is a peculiar universe”: HUA, Shapley to Russell, October 31, 1917.
126 “the minimum distance of the Andromeda Nebula”: Shapley (1917b), p. 216.
127 “like a winding spring”: Slipher (1917a), p. 62.
127 “V. M. does a little, Hale a little more, and I much”: HUA, Shapley to Russell, September 3, 1917.
127 “inclined to believe in the reality of the [spirals'] internal proper motions”: HUA, Russell to Shapley, November 8, 1917.
127 “word was law”: Payne-Gaposchkin (1984), p. 177.
127 “the general plan of the sidereal system … bearing on the structure of the universe”: Shapley (1918a), p. 92.
128 “striking”: Shapley (1918b), p. 168.
128 “impossible to count every star shown”: Melotte (1915): 168.
128 around 20,000 parsecs … away: Shapley (1919d), p. 313.
128 In 1909 the Swedish astronomer Karl Bohlin even dared to suggest that the center of the galaxy was in that direction: K. Bohlin, Kungliga Svenska Vetenskapsakademiens handlingar 43:10 (1909).
128 couldn't wait that long to spread the news: It should be noted