Gravity is a fascinating phenomenon, and scientists have been trying to understand the mechanics behind it. Two well-known theories on gravity present different understandings of how gravity works: one from Newton's law of Gravitation, and the other from Einstein's General Relativity. While Einstein's theory can explain a phenomenon called gravitational precession, observed in the orbit of Mercury and the recently reported star S2, Newton's equation fails to address the issue. HP explains the differences between the two competing theories and elaborates on how a special phenomenon proves Einstein's theory right.