I understand that relativity was 'derived' from observations that showed that Newtonian Gravity was not the correct description of reality. Essentially it is wrong.
So in my opinion Relativity (that something about space and time is relative) is a stand alone model. The Newtonian model is a very good approximation, but in a strict scientific sense, it is not a description of what nature does.
This is not my theory, and it not even relativity! However, I base the model on the tests that confirm that relativity is real and correct.
That time and space and matter and energy do things with each other and are relative.
So I have worked from what we know and confirm to be true. The four tests of General relativity
Perihelion Precession
Deflection (bending) of light
Gravitation shift of light
and 'dragging'.
