H-0 - THE INCREDIBLE SHRINKING CONSTANT 1925-1975

Authors
Citation
V. Trimble, H-0 - THE INCREDIBLE SHRINKING CONSTANT 1925-1975, Publications of the Astronomical Society of the Pacific, 108(730), 1996, pp. 1073-1082
Citations number
133
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Publications of the Astronomical Society of the Pacific
ISSN journal
0004-6280 → ACNP
Volume
108
Issue
730
Year of publication
1996
Pages
1073 - 1082
Database
ISI
SICI code
0004-6280(1996)108:730<1073:H-TISC>2.0.ZU;2-7
Abstract
The story of the Hubble constant logically begins just where the Curti s-Shapley debate on the distance scale of the universe ended, with Hub ble's discovery of Cepheid variables in several nebulae that we now re cognized as galaxies within the Local Group, which settled the issue o f the existence of external galaxies. Hubble's own value of H was in t he range of 500-550 km s(-1) Mpc(-1). The ''best buy'' value shrank in several large steps beginning in 1952, each being predicated on the r ecognition of some fundamental mistake in the previous distance scale calibrations. But it shrank more for some workers than for others, and by 1975 there was a clear polarization between a ''long'' and a ''sho rt'' distance scale. On the theoretical side, important events were th e recognition that general relativity permits, indeed nearly requires, an expanding universe; the gradual elimination of alternative explana tions of redshift-distance relations; and the repelling of a late assa ult in the form of steady-state cosmology, within whose framework H-0 is a well-defined, never-varying number of only moderate importance.