Einstein’s theory of gravitation.
A model for gravity quite unlike Newton’s was presented by Einstein in his general theory of relativity. Einstein perceived a gravitational field as a geometrical warping of four-dimensional space and time. He realized that bodies put dents in space and time somewhat like a massive ball. The more massive the ball, the greater the dent or warp. If we roll a marble across the top of the bed but away from the ball, it will curve as it rolls across the indented surface of the water bed. If the curve closes on itself, the marble will orbit the ball in an elliptical path. From a Newtonian viewpoint, the marble curves because it is attracted to the ball. From Einstein viewpoint, the marble curves not because of any force, but because the surface on which it moves curves.