# Dictionary Definition

oscillation

### Noun

1 the process of oscillating between states

2 (physics) a regular periodic variation in value
about a mean [syn: vibration]

3 a single complete execution of a periodically
repeated phenomenon; "a year constitutes a cycle of the seasons"
[syn: cycle]

# User Contributed Dictionary

## English

### Pronunciation

- Rhymes: -eɪʃǝn

### Noun

- the act of oscillating or the state of being oscillated
- a regular periodic fluctuation in value about some mean
- a single such cycle

#### Related terms

#### Translations

- Czech: kmitání , oscilace
- Italian: oscillazione

# Extensive Definition

- ''For other uses, see oscillator (disambiguation)

## Simplicity

The simplest mechanical oscillating system is a
mass attached to a linear spring,
subject to no other forces; except for the point of equilibrium,
this system is equivalent to the same one subject to a constant
force such as gravity. Such a system may be
approximated on an air table or ice surface. The system is in an
equilibrium
state when the spring is unstretched. If the system is displaced
from the equilibrium, there is a net restoring force on the mass,
tending to bring it back to equilibrium. However, in moving the
mass back to the equilibrium position, it has acquired momentum which keeps it moving
beyond that position, establishing a new restoring force in the
opposite sense. The time taken for an oscillation to occur is often
referred to as the oscillatory period.

The specific dynamics
of this spring-mass system are described mathematically by the
simple harmonic oscillator and the regular periodic
motion is known as simple
harmonic motion. In the spring-mass system, oscillations occur
because, at the static
equilibrium displacement, the mass has kinetic
energy which is converted into potential
energy stored in the spring at the extremes of its path. The
spring-mass system illustrates some common features of oscillation,
namely the existence of an equilibrium and the presence of a
restoring force which grows stronger the further the system
deviates from equilibrium.

The harmonic
oscillator offers a model of many more complicated types of
oscillation and can be extended by the use of Fourier
analysis.

## Damped, driven and self-induced oscillations

In real-world systems, the
second law of thermodynamics dictates that there is some
continual and inevitable conversion of energy into the thermal
energy of the environment. Thus, damped oscillations tend to
decay with time unless there is some net source of energy in the
system. The simplest description of this decay process can be
illustrated by the harmonic oscillator. In addition, an oscillating
system may be subject to some external force (often sinusoidal), as when an AC
circuit
is connected to an outside power source. In this case the
oscillation is said to be driven.

Some systems can be excited by energy transfer
from the environment. This transfer typically occurs where systems
are embedded in some fluid
flow. For example, the phenomenon of flutter in aerodynamics occurs when an
arbitrarily small displacement of an aircraft wing (from its equilibrium) results
in an increase in the angle of
attack of the wing on the air
flow and a consequential increase in lift
coefficient, leading to a still greater displacement. At
sufficiently large displacements, the stiffness of the wing
dominates to provide the restoring force that enables an
oscillation.

## Coupled oscillations

The harmonic oscillator and the systems it models
have a single
degree of freedom. More complicated systems have more degrees
of freedom, for example two masses and three springs (each mass
being attached to fixed points and to each other). In such cases,
the behavior of each variable influences that of the others. This
leads to a coupling of the oscillations of the individual degrees
of freedom. For example, two pendulum clocks mounted on a common
wall will tend to synchronise. The apparent motions of the
individual oscillations typically appears very complicated but a
more economic, computationally simpler and conceptually deeper
description is given by resolving the motion into normal
modes.

## Continuous systems - waves

As the number of degrees of freedom becomes
arbitrarily large, a system approaches continuity; examples include a
string or the surface of a body of water. Such systems have (in the
classical
limit) an infinite
number of normal modes and their oscillations occur in the form of
waves that can
characteristically propagate.

## Examples

See also: list
of wave topics

### Mechanical

- Double pendulum
- Quantum harmonic oscillator
- Foucault pendulum
- Helmholtz resonator
- Playground swing
- String instruments
- Tuning fork
- Vibrating string
- Oscillations in the Sun (helioseismology) and stars (asteroseismology)

### Electrical

- Alternating current
- Armstrong oscillator
- Astable multivibrator
- Blocking oscillator
- Clapp oscillator
- Colpitts oscillator
- Delay line oscillator
- Electronic oscillator
- Hartley oscillator
- Oscillistor
- Pierce oscillator
- Relaxation oscillator
- RLC circuit
- Royer oscillator
- Vačkář oscillator
- Wien bridge oscillator
- Oscillators and Multivibrators
- Virtual Cathode Oscillator

### Electro-mechanical

### Optical

- Laser (oscillation of electromagnetic field with frequency of order 10^Hz)
- Oscillator Toda or self-pulsation (pulsation of output power of laser at frequencies 10^Hz -- 10^Hz in the transient regime)
- Quantum oscillator may refer to an optical local oscillator, as well as to a usual model in quantum optics.

### Economic and social

- Business cycle
- Generation gap
- Malthusian economics
- News cycle

### Climate and geophysics

## See also

- BIBO stability
- Critical speed
- Dynamical system
- Feedback
- How do We Create Sinusoidal Oscillations? from Circuit Idea reveals the philosophy of LC oscillations
- Oscillation (mathematics)
- Periodic function
- Reciprocation
- Rhythm
- Self oscillation
- Signal generator
- Strange attractor
- Structural stability
- Time period
- Tuned mass damper
- Vibration
- Vibrator

## External links

- Vibrations - a chapter from an online textbook
- Dealing Vibration at work

oscillation in Bosnian: Oscilovanje

oscillation in Catalan: Oscil·lació

oscillation in Czech: Kmitání

oscillation in Danish: Oscillator

oscillation in German: Schwingung

oscillation in Estonian: Võnkumine

oscillation in Modern Greek (1453-):
Ταλάντωση

oscillation in Spanish: Oscilación

oscillation in Persian: نوسان

oscillation in French: Oscillation

oscillation in Korean: 진동

oscillation in Croatian: Titranje

oscillation in Ido: Ocilo

oscillation in Indonesian: Osilasi

oscillation in Italian: Oscillazione

oscillation in Hebrew: תנודה

oscillation in Latvian: Svārstības

oscillation in Malay (macrolanguage):
Ayunan

oscillation in Dutch: Trilling

oscillation in Japanese: 振動 (物理現象)

oscillation in Norwegian: Oscillasjon

oscillation in Polish: Drgania

oscillation in Portuguese: Vibração

oscillation in Romanian: Oscilaţie

oscillation in Russian: Колебания

oscillation in Russian: Виброизоляция

oscillation in Simple English: Oscillator

oscillation in Slovak: Vibrácia

oscillation in Finnish: Oskillaattori

oscillation in Swedish: Oscillation

oscillation in Vietnamese: Dao động

oscillation in Ukrainian: Коливання

oscillation in Chinese: 振动

# Synonyms, Antonyms and Related Words

alternation, beat, cyclicalness, equivocation, fluctuation, intermittence, intermittency, meter, pendulation, pendulum
motion, periodicalness, periodicity, piston motion,
pulsation, reappearance, recurrence, regular wave
motion, reoccurrence, return, rhythm, seasonality, seesawing, shifting, shilly-shally,
shilly-shallying, shuffling, teeter-tottering,
teetering, tottering, undulation, vacillation, variation, vicissitude, wavering, wobbling