Related papers: Vesto Slipher and the First Galaxy Redshifts
Vesto Melvin Slipher was the first astronomer to clearly define the factors that determine the "speed" of a nebular spectrograph. This brief historical summary recounts the way these ideas developed and how Slipher's early work on galaxy…
By 1917, V.M. Slipher had singlehandedly established a tendency for 'spiral nebulae' to be redshifted (21 out of 25 cases). From a modern perspective, it could seem surprising that the expansion of the universe was not announced at this…
Of the first two relativistiv world models, only the one by de Sitter predicted redshifted spectra from far away astronomical objects. Slipher's redshifts therefore seemed to arbitrate against Einstein's model which made no such…
A brief history of the discovery of the expanding universe is presented, with an emphasis on the seminal contribution of VM Slipher. It is suggested that the well-known Hubble graph of 1929 could also be known as the Hubble-Slipher graph.…
Based on historical facts, revisited from a present-day perspective, and on the documented opinions of the scientists involved in the discovery themselves, strong arguments are given in favor of a proposal to include prominent astronomer…
A new database from the NASA/IPAC Extragalactic Database (NED) of galaxy Distances (NED-D), normally the source for the newest precision-based estimates, provides access to the oldest redshift-independent extragalactic distances in the…
Why do some discoveries, which appear in hindsight to be obviously major discoveries, have so little impact when they were made. These are discoveries that were ahead of their time, but for some reason the scientific community was not ready…
Redshift observations of galaxies outside the Local Group are fairly common in extragalactic astrophysics. If redshifts are interpreted as arising from radial velocities, these must be corrected by the contamination of the solar motion. We…
Recently E. Harrison has argued the Red Shift distance law proposed by Hubble and velocity-distance law developed later on theoretical grounds has no general proof demonstrating the two laws are actually equivalent. It is the purpose of…
The recent literature of astronomy and cosmology has included a good many suggestions for "who first recognized the expansion of the universe?" with cases having been made for Lemaitre, Lundmark, de Sitter, Slipher, Shapley, Friedmann,…
Hubble's name is associated closely with the idea of an expanding universe as he discovered the relation between the recession velocity and distances of galaxies. Hubble also did a lot of pioneering work on the distribution of galaxies in…
Six of the principal galaxy distance indicators are discussed: Cepheid variables, the Tully-Fisher relation, the Dn-sigma relation, Surface Brightness Fluctuations, Brightest Cluster Galaxies, and Type Ia Supernovae. The role they play in…
Who discovered the expanding universe? Was it Hubble, or Lema\^itre, or was it just the end result of a long series of investigations? In this article we summarise the main steps and contributions that led to one of the most exciting…
Arthur Stanley Eddington was one of the leading astronomers and theorists of his generation and a prominent proponent of the general theory of relativity. Yet when his former assistant Georges Lemaitre sent him a paper in 1927 suggesting…
The objective of this paper is not simply to present an historical overview of Einstein's cosmological considerations, but to discuss the central role they played in shaping the paradigm of relativistic cosmology. This, we'll show, was a…
Recently much attention has been paid to the discovery of Hubble's law: the linear relation between the rate of recession of the distant galaxies and distance to them. Though we now mention several names associated with this law instead of…
From the first observations made by Slipher, our understanding and interpretation of the cosmological redshift was evolving until reaching the current consensus, through the expanding universe and the emergence of modern physical cosmology…
The Doppler effect is commonly used to infer the velocity difference between stars based on the relative shifts in the rest-frame wavelengths of their spectral features. In dynamically-cold systems with a low velocity dispersion, such as…
The systemic velocity or redshift of galaxies is a convenient tool to calculate their distances in the absence of primary methods, but the uncertainties on these flow distances may be substantial due to galaxy peculiar motions. Here, we…
In the year 1924, a paper by Carl Wirtz appeared in Astronomische Nachrichten, entitled 'De Sitter's cosmology and the radial motion of spiral galaxies'. This paper and its author remained largely unnoticed by the community, but it seems to…