Chapter 2: The Matrix
In the famous movie, The Matrix, Morpheus says, "The Matrix is everywhere. It is all around us. Even now, in this very room." Morpheus was not far off the mark, for there is a theory in physics called the matrix string theory where essentially, reality is governed by a set of matrices. But while a matrix is one entity in the movie, a matrix in physics is a concept that is used again and again to model reality.
As you will see, the definition of a matrix is deceptively simple, but its power derives from all the ways mathematicians have defined that it can be used. It is a central object in quantum mechanics and, hence, quantum computing. Indeed, if I were forced to select the most important mathematical tool in quantum computing, it would be a matrix.
In this chapter, we are going to cover the following main topics...