ABSTRACT
How do we describe the state of a quantum mechanical physical system in a mathematically precise way? How do we ascribe physical properties to this system? How does the system evolve in time? How do its properties change when it interacts with another system or a force? How do we measure and determine its properties? These are the questions whose answers are encoded in the laws of quantum mechanics to be set down in this chapter. They have been inscribed in this form after nearly half a century of experimental observations, theoretical modeling, and intellectual gymnastics to tie up the two in a satisfactory and robust structure.
