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Points from Foregoing Letters

Nature volume 139, page 332 (20 February 1937) | Download Citation



BY expressing the age of the universe as derived from cosmological theories (2 × 10 years) in units provided by the atomic constants (/), Prof. P. A. M. Dirac obtains a number comparable with the ratio of the electric to the gravitational force between the electron and the proton (10). He suggests that this ratio, and also that between the mass of the universe and the mass of the proton (10) are functions of the age of the universe. This leads him to the supposition that the amount of matter in the universe is constantly increasing while the gravitational constant decreases. He introduces a new time variable (= log) similar to Milne's distinction between dynamic time as measured by pendulums, etc., and kinematic time measured by radioactive and atomic phenomena.

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