In a theory of Dirac and Brans, it decreases due to cosmological expansion.  
In a theory of Dirac and Brans, it decreases due to cosmological expansion.  With Planck's constant and the speed of light it forms the Planck length, the fundamental scale of string theory. First measured in 1798 with a torsion balance by Cavendish, FTP, identify this constant with value 6.67 times 10 to the minus eighth centimeters cubed per gram second squared.
In a theory of Dirac and Brans, it decreases due to cosmological expansion.  
universal gravitational constant or G