One of the most exciting scientific adventures of all time is the search for the ultimate nature of physical reality, a hunt that in the past century has yielded such breakthroughs as Einstein's theory of relativity and quantum mechanics, two theories that radically altered our picture of space, time, gravity, and the fundamental building blocks of matter.
The latest advance in this epic quest is string theory—known as superstring or M-theory in its most recent versions. The "M" of M-theory is an arbitrary label, but some physicists believe it stands for mysterious or magical. Marvelous also qualifies, because there is something quite wonderful about this beautiful and startling idea.
