In this course statistical mechanics is applied to two important cases. The principles of statistical mechanics can be used to derive thermodynamic equations of state. They also lead to profound insights into the meaning of thermodynamic quantities like temperature and entropy. When you study statistical mechanics on the spiral staircase physics curriculum, you return to thermodynamics at a higher level. Your upward journey along the physics curriculum spiral staircase has brought you to electromagnetism at the junior-senior level.
Electromagnetic fields are vectors which vary in complicated ways through space and time.
The laws of electromagnetism, which describe these fields, are all expressed in terms of vector calculus. Therefore, the course begins with a rigorous section on vector calculus and its application in different coordinate systems. Initially, it makes sense to study electric and magnetic effects separately. This wisely postpones the full complexity of electromagnetism. Purely electric effects are studied first.