Waves and oscillations are present everywhere in nature and one encounters them in several areas of physics. An oscillation may be defined as a disturbance in a physical system that repeats in time, while a wave is a disturbance in a system which both repeats in time and is periodic spatially. In the case of a simple pendulum, an oscillation in general involves a continuous back and forth flow of both kinetic and potential energy. For example, both electromagnetic and acoustic waves are present in different physical mechanisms; however, they have many common properties. It was shown in the previous chapter the behavior of the electromagnetic waves while waves in optics will be discussed in detail in a subsequent chapter. Some of the famous texts which

deal with waves and oscillations are by Crawford [116], French [123], Main [143], and Fitzpatrick [120].