 

Dirac's Cosmology and Mach's Principle R. H. DICKE Palmer Physical Laboratory, Princeton University, New Jersey. THE dimensionless gravitational coupling constant with m_{p} the mass of some elementary particle, for definiteness taken as the proton, is such a small number that its significance has long been questioned. Thus Eddington^{1} considered that all the dimensionless physical constants, including this one, could be evaluated as simple mathematical expressions. Dirac^{2} considered that such an odd number must be related to other numbers of similar size, characterizing the structure of the universe. However, most physicists seem to believe that a dimensionless constant, such as (1), is provided by Nature, cannot be calculated, and is not in any way related to other numbers.
© 1961 Nature Publishing Group Privacy Policy 