Equivalence principle + light speed postulate =

[Loren Booda]

It seems to me that Einstein's equivalence of gravitational acceleration and non-gravitational acceleration, when combined with his constancy of light speed in vacuuo, should yield a constancy of gravitational speed in vacuuo.

 

[HallsofIvy]

It's not necessary to appeal to the constant velocity of light or relativity in general.

F= G(gravitational mass A)(gravitational mass B)/r²

(inertial mass A)(acceleration of A)= F so as long as inertial mass= gravitational mass:

acceleration of a= G(gravitational mass B)/r², a constant.

 

[Loren Booda]

How does this show that the velocity of gravitational propagation is constant?

 

[Chronos]

pick a constant, any constant. if you don't like c, take g. the math still works out to the same conclusion.

 

[Loren Booda]

So where is the constant of velocity in Hall's equations?

 

[timetraveldude]

pick a constant, any constant. if you don't like c, take g. the math still works out to the same conclusion.

All you have proven is that the acceleration due to gravity is dependent only upon the object causing the accelerationa and not the accelerated object. Loren's question has to do with the propagation speed of gravity. Perhaps Loren could explain more clearly what is meant by this.

 

[Loren Booda]

The speed of light propagation is c. Propagation speed in general may be finite or infinite. Simply put, propagation speed is distance per the time that particle action takes to travel over that distance.

Here I hypothesize that

Einstein's equivalence of gravitational acceleration and non-gravitational [inertial] acceleration, when combined with his constancy of light [propagation] speed in vacuuo, should yield a constancy of gravitational [propagation] speed in vacuuo.