here is one of his claims:"According to Popper's "Logic of Scientific Discovery" Einstein's reasoning is not only very strong, but in fact too strong. For it is, of course, true that the ray of light falling into the accelerating box will form a parabolic curve. But this is true not only for light, but also for any other ray traveling at constant speed, and entering the box at an angle of . The shape of the parabolic curve will, of course, vary depending on the velocity of the ray and the acceleration of the box, but if one of two intersecting systems of coordinates is moving at constant velocity while the other is being accelerated the function of the intersection must necessarily be a parabolic curve. This is not only true for rays of light; it is even true for rays, or lines, that exist only in our imagination, or for a box without top or bottom, and therefore without gravitational field. It is independent of any physical properties of those rays, and has nothing to do with gravitation, but simply consists of a geometrical description of two bodies, or systems of coordinates, moving at speeds relative to each other, when one of them is being accelerated and the other is not. It is the result of a valid mathematical inference which can therefore never be refuted. It is a simple truism of analytical geometry and therefore belongs to mathematics, but not to physics. So it falls victim to Einstein's own criterion: because it is certain it does not refer to reality. And if it does not refer to reality, then it does not describe a physical property of light, or of space. And in Popper's terminology the theory of curved space is non-empirical because it cannot be refuted by any conceivable experiment, or physical property of light[3]. Therefore we may not infer from this theory that space is curved in reality, and that light will be deflected in the gravitational field. "