String Theory For Dummies, 2nd Edition

Chapter 11

M-Theory and Beyond: Bringing String Theory Together

IN THIS CHAPTER

Dualities present a puzzle

Re-energizing the movement with M-theory

Thinking about branes

Using multidimensional branes in string theory

Chapter 10 ends with five versions of string theory. Theorists continued their work but were uncertain how to take these findings. A new insight was needed to generate further progress in the field.

In this chapter, we explain how that insight came about in the form of M-theory, which unified the five string theories into one theory. We discuss how string theory was expanded to include objects with more than one dimension called branes. We introduce some possible insights that may help explain what M-theory is trying to describe.

Introducing the Unifying Theory: M-Theory

At a conference in 1995, physicist Edward Witten proposed a bold resolution to the problem of five distinct string theories. In his theory, based on newly discovered dualities, each of the existing theories was a special case of one overarching string theory, which he enigmatically called M-theory ...