Fluctuation
Oscillations, oscillations - specific movements or changes in the state of systems of different physical nature, for which there is a certain repetition in time. If this occurs over an identical period of time, the period T, oscillations are called periodic. "The world in which we live is surprisingly inclined to fluctuate ... Even the atoms, of which we are developing, are fluctuating." The study of the theory of oscillations is an essential component of the fundamental training of engineers of many specialties. Fluctuations can have a wide variety of nature, for example, mechanical vibrations of bodies, fluctuations of pressure and temperature, current, voltage, etc.