Part 2: Comparing Einstein's and Newton's Models of Gravity In 1915, Albert Einstein proposed a totally different model of gravity based on geometry rather than force. In general relativity, the gravitational field describes the amount of curvature of spacetime caused by mass and energy. The first success of general relativity was to correctly predict the precession of Mercury by providing a correction of +0.012 per Earth-century. Let's explore how Einstein's model differs from Newton's. Newton's Model First consider how Newton's model explains the effect of a massive object on the trajectory of a rocket. 1. The Flat-Space Template shows the trajectory of a rocket moving at constant velocity through empty space. What conclusions can you draw about the forces acting on the rocket? 2. Draw the Sun at the centre of the template. According to Newton, what will happen to the rocket's trajectory now that there is a large mass nearby? Why? 3. On the template, sketch the trajectory that you would expect the rocket to follow now that it is near a massive object. Permission to reproduce this page is granted for student use