The speed of gravity

The speed of sound at sea level is 340 m/s. The speed of light in a vacuum is 300,000,000 m/s. But what is the speed of gravity? How would you even measure it?

Scientists have gotten closest by measuring the speed of gravity waves. Basically, how long does the gravitational changes due to an exploding star take to affect other stars.

Some scientists believe that these gravity waves travel at the speed of light since they are limited by that of the observer and the observer only has EM transmissions to measure.

Some experimental physicists conclude that gravity travels at 2 X 10 to the tenth times c or a million, billion times the speed of light. If that is the case, that is pretty darned fast!

I chose to accept the faster figure as my working figure in Rome's Revolution. All of the interactions that occur with PPT transmissions occur virtually instantaneously. While PPT transceivers have an effective range of a light year or so, within that radius, the interaction is more or less real time.

Postulating that virtually instantaneous transmissions can occur over such large distances allowed the Overmind to form and also for MASAL to operate as he did.

If it is ever discovered that gravity only travels at the speed of light, I may have to rework some sections or invoke other dimensions (string theory anybody?) to get the velocity back up to where I need it.