This paper presents research results from the application of jitter in the fields of physical phenomena modeling, modulation and multiple access. This kind of jitter, known as “clock changes,” is applied to stationary processes. The paper discusses how some physical phenomena and atmospheric channels can be modeled using stationary Gaussian delays, and how stationary clock changes can be used to study non-uniform sampling. It also explains how periodic clock changes can be used as a spread spectrum modulation process for digital signals.