[golf_sceptic]

The laws of physics in this case are invariant regardless of frame of reference.

Ok. Let's try that assertion out with a question. Why in the frame of reference of the rock does the centrifugal force act on the rock when in an inertial frame the centrifugal force acts on the boy?

A non-inertial frame of reference changes everything. Forces appear like the ones which the camera on the rock shows affecting the trees and the grass. It becomes a mess. The simple reason I wish to keep things in a non-rotating reference frame is because physics in a rotating frame is so complicated, but will after a lot of hard work provide the same answers (for the ball) as in an inertial frame.

Newton's law that "an object at rest will remain at rest unless a resultant force is applied" becomes "an object at rest will only remain at rest if a centripetal force is applied". See what I mean?

I have no problem if you wish to disagree, but be so kind as to point out the error in what I say rather than discussing motives and making condecending remarks like "it's nice that you learned your physics in a different way".

I will, however, be very interested in reading your explanation of the physics of the throw out effect in a non-inertial frame of reference if you want to discuss it.