Kinematics and WorldStructure
Abstract
The idealized cosmological problem, in which the nebulae are considered as particles in homogeneous flow, is analyzed from the standpoint of the operational methodology, allowing the fundamental observers the use only of clocks, theodolites, and lightsignals. It is found, as an extension of the HelmholtzLie solution of the problem of physical space, that such a spacetime necessarily admits the introduction of an invariant Rie mannian metric of precisely the form and generality of that on which the general rela tivistic theory of cosmology is based, and in terms of which all given elements can be interpreted in the same way as in the relativistic theory
 Publication:

The Astrophysical Journal
 Pub Date:
 November 1935
 DOI:
 10.1086/143681
 Bibcode:
 1935ApJ....82..284R