This book is intended to answer the following questions: 1. What is ? 2. Why is the momentum order? 3. When and where does irreversibility occur? 4. How can the matter become more orderly? In a relatively well-understood field of my research, the new concepts will be used to explain some of the problems that have puzzled people for about 150 years. The is a type of energy that is missing, not the heat extracted from known energy. It is the potential energy of the spatial configuration of the momentum at the location of the material in the system constructed under known forces. There are two...