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V. Trimble (U. California Irvine & U. Maryland)
Newton declared that, although light could interact with matter and be affected by it, the space between the stars was perfectly transparent. William Herschel concurred, and so used his ``star gauging" to put us very near the center of a small, lenticular galaxy. The misconception survived the discovery of individual dark clouds (E.E. Barnard and others) and was incorporated into Shapley's calibration of the distance scale for Cepheids and RR Lyraes. The result was a galaxy too large and, when Hubble built on Shapley's results, an extragalactic distance scale too small. Those who disagreed between 1850 and 1930 were somehow less influential (Secchi, Ranford, Wolf, King, and even H.D. Curtis). Only with Trumpler's 1930 publication (Lowell Obs. Bull. 14, 154, No. 420) of the relationship between angular diameter and apparent brightness of star clusters did the community accept that all of interstellar space was capable of swallowing starlight. Mineur in 1939 was the first to incorporate this general obscuration into a Cepheid distance scale (and his l - 1.5 mag per kpc was about right), but not until 1952, at the Rome IAU, did most astronomers catch on. It is just possible that, if this had all been sorted out earlier, steady state cosmology would never have been proposed.