  Gravitational waves propagate at the speed of light in general relativity,
because of its special relativistic basis. However, light propagation is linked
to the electromagnetic phenomena, with the permittivity and permeability
constants as the determining factors. Is there a deeper reason why waves in a
geometric theory of gravity propagate at a speed determined by electromagnetic
constants? What is the relation between gravity's own constants and the speed
of gravitational waves? Our attempt to answer these fundamental questions takes
us far and deep into the universe.
