1.) What controls the rate of drop off to whatever you want to call that bottom value?
Looking at your diagram (let’s call it Fig. 1 in case there are more) it is easy to imagine that something needs to act on the Earth to stop it falling further down that well, possibly to infinity. Remember, though, that this is just a small fraction of a 2D model of the real thing. To be a complete 2D illustration there would have to be an infinite number of gravity wells surrounding the Earth. Even without attempting the impossible, you could draw enough gravity wells around the Earth to get rid of that apparent, but totally wrong, view that something – gravity? – is pulling the Earth “downward” in Fig.1.
Gravity is, if it is to be thought of in terms of gravity wells, an infinite number of wells, radiating in 3D from the Earth.
There is no downward direction, except towards the Earth, at the centre of this infinite number of gravity wells.
Why would this be seen as a situation in which any force is trying to move the Earth in any direction from its apparently stable position at the centre of this setup?
If there is such a force, would it not be balanced by an equal force acting on the Earth from an infinite number of directions?
