Gravity

In the 17th century, Sir Isaac Newton formulated his Law of Universal Gravitation to explain the observed motions of astronomical objects such as the moon and the planets. In this Chapter we will see how that this law, when supplemented with Newton's other laws, accurately describes the orbital motion of satellites and planets. We will also point out the deficiencies in Newton's theory that led Einstein to formulate his General Theory of Relativity. Einstein's theory radically altered our view of space and time, and predicted, among other things, the existence of black holes.