A (brief) Introduction

One of the first predictions of Einstein's Theory of General Relativity was the existence of gravitational waves. Gravitational waves are predicted to propagate at the speed of light and represent a time-dependent distortion of the local space and time coordinates. Just as electromagnetic waves are produced by the acceleration of charge, gravitational waves are predicted to be produced by the acceleration of mass. Gravitational waves, however, differ from electromagnetic waves in a number of ways. While only a single charge is needed to produce electromagnetic waves, at least two masses are required to produce gravitational waves. The gravitational field is also very weak so that only catastrophic events are expected to produce detectable waves. Possible events include the collision of two astronomical objects and the collapse of a large astronomical object.