Table of Contents Author Guidelines Submit a Manuscript
Physics Research International
Volume 2012 (2012), Article ID 567873, 4 pages
Research Article

Variation of the Gravitational Constant in the Radiation-Dominated Universe

Konfluence Research, 6009 Olympic, Manitou Springs, CO 80829, USA

Received 29 September 2011; Accepted 4 December 2011

Academic Editor: Bijan Saha

Copyright © 2012 L. L. Williams. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The unification of classical electrodynamics and general relativity within the context of five-dimensional general relativity (Kaluza, 1921, and Thiry, 1948) contains a scalar field which may be identified with the gravitational constant, G. The field equations of this theory are solved under conditions of the Robertson-Walker metric for flat space, for a radiation-dominated universe—a model appropriate for the early history of our universe. This leads to a cosmology wherein G is inversely proportional to the Robertson-Walker scale factor. This result is discussed in the context of the Dirac large number hypothesis and in the context of an expression for G in terms of atomic constants.