Oscillation is a periodic motion that repeats itself about a central point or axis. The term can be used to describe the motion of a pendulum or other object that swings back and forth, or the alternating current in an electrical circuit. Oscillations occur naturally in many systems, including the Earth’s climate, the human respiratory system, and populations of animals.
The word oscillation comes from the Latin word oscillare, which means “to swing.” Pendulums were first studied by Galileo Galilei in 1581. He found that the time it takes for a pendulum to swing back and forth is independent of its amplitude (the distance it swings). This discovery led to the development of accurate timekeeping devices such as clocks and watches.
In an electric circuit, oscillations occur when there is an imbalance between the supply of energy and the demand for energy. When this occurs, current will flow back and forth until equilibrium is reached. The frequency of an electric oscillation is determined by the characteristics of the circuit elements (such as resistors, capacitors, and inductors) and by external factors such as power supply voltage.
Oscillations also occur in nature due to feedback loops. Feedback loops are created when a change in one system creates a change in another system which then affects the first system again (positive feedback) or counters it (negative feedback). Feedback loops can result in either stability or instability within a system. For example, population cycles observed in nature are thought to be caused by positive feedback between predation pressure and population density: when prey are scarce predators put more pressure on them which leads to further decline in numbers; eventually this causes predator populations to collapse leading to release from predation pressure and an increase in prey numbers again—thus starting the cycle anew (see Figure 1). Climate oscillations such as El Niño/La Niña events are also thought to be driven by feedback loops involving changes in ocean temperature affecting atmospheric conditions which then influence ocean temperature once more—amplifying or dampening effect depending on whether positive or negative feedback predominates