" The universal character of the centrifugal forces leaves us impotent as to discern whether what is going on inside the carrousel is because we are rotating with respect to terra firma (remember my eyes are closed), or because – for some unknown reason unrelated to motion – radial gravitational field has temporarily emerged while the carrousel is as in repose as it was before the given impulse. The latter would have certainly been the interpretation adopted by an intelligent being, had s/he been born and grown up inside the carrousel, without any access whatsoever to the exterior world. "
― Felix Alba-Juez , When Celestial Dynamics becomes Kinematics Again - General Relativity (Relativity free of Folklore #7)