Scientists have been looking for the “Theory of Everything.” One person who thinks he found it is physicist Brian Greene, who wrote The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory. Greene’s “string theory” is a complicated concept suggesting that at its tiniest level everything consists of combinations of vibrating strands, or strings. He has described his theory as “a framework with the capacity to explain every fundamental feature upon which the world is constructed.”