This reply is about G.
And scientist was observing that movement to see an effect. Acceleration is a change of velocity over time.
a = [V(final) - V(initial)] / [t(final) - t(initial)]
According to this formula, initial velocity CAN be zero (Newton’s First Law, an object at rest v=0).
Any change in velocity after zero was by caused a force. Now, before you jump to a conclusion on what that force may be, just remember that G was measured using the Cavendish experiment.
Within that experiment the force that was used was torque.
F = (k * theta)/L
Where k is the torsion coefficient, theta is the angle between rest position and the equilibrium points measured in radians, and L is the total length of the bar in meters.
So if we take the gravitational force equation and solve for G, we get:
G = F(r^2)/(m1 * m2)
We can replace F in this equation with (k * theta)/L and get:
G = [k * theta * r^2]/(L * m1 * m2)
Here things get a little complicating because you have to find the torsion coefficient (k).
I’ll let you finish the rest and you interpret the motion as you see it.
https://www.school-for-champions.com/science/gravitation_cavendish_experiment_derivation.htm
How I see it is, motion was used to calculate torsion coefficient (k) using oscillation periods.
k = (4 * pi^2 * I)/T^2
Where T is oscillation period and I is the moment of inertia. When something is oscillating what is it doing? Going back and forth, right?
Now obviously this is a standard pendulum in the gif above, but during the Cavendish Experimet, the oscillation has brief moments of v = o and a = 0 while oscillation occurs.
For this experiment, “the gravitational force attracts the the balls and provide torque on the moment arm and twist the wire holding the balance” (from the link above)
In the end, this experiment does not PROVE that motion or mass is the SOURCE of gravity. However, it does explain where the motion in the gravitational force equation comes from. The motion in this experiment is showing the change of velocity, which is acceleration, due to the mass of the objects causing a gravitational force that provides torque on the moment arm while oscillation occurs to measure the value of G.
G is the residual value of the gravitational force equation found through this experiment. G has no physical baring on the gravitational force equation. It’s just an emperical physical constant that is a result from this test.
And to be clear, I wasn’t using this equation to prove my stance that gravity is created from mass. I’m merely explaining where the motion in the gravitational force equation is coming from. And since I have a better understanding how this experiment works, my stance remains because of the oscillating pendulum and the fact that it has to reach v = 0 and a = 0 at some point to measure G.