Paul Dirac (1902-1984) presents a cosmological theory where the gravitational constant decreases slowly so that the age of the universe divided by the atomic light-crossing time always equals the ratio of the electric force to the gravitational force between a proton and electron
Editors. "Diracs cosmological theory". The Literary Encyclopedia. First published 01 May 2009; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=6558, accessed 21 April 2015.]