It is my understanding that the velocity of gravity is assumed to be that of electromagnetic velocity i.e. “c” in General Relativity. We know from experiments that space has the properties of permittivity (electric capacitance per length) and permeability (magnetic inductance per length) and that these properties store energy by acting as inertia in conjunction with a restoring force. We also know that these two properties of space fix the velocity of electromagnetic waves to “c”. My question is; what properties of space determine the velocity of gravity?