perturbation

American  

[pur-ter-bey-shuhn] / ˌpɜr tərˈbeɪ ʃən /

noun

1. the act of perturbing.

2. the state of being perturbed.

3. mental disquiet, disturbance, or agitation.

4. a cause of mental disquiet, disturbance, or agitation.

5. Astronomy. deviation of a celestial body from a regular orbit about its primary, caused by the presence of one or more other bodies that act upon the celestial body.

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perturbation British  

/ ˌpɜːtəˈbeɪʃən /

noun

1. the act of perturbing or the state of being perturbed

2. a cause of disturbance or upset

3. physics a secondary influence on a system that modifies simple behaviour, such as the effect of the other electrons on one electron in an atom

4. astronomy a small continuous deviation in the inclination and eccentricity of the orbit of a planet or comet, due to the attraction of neighbouring planets

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perturbation Scientific  

/ pûr′tər-bā′shən /

1. A small change in a physical system, most often in a physical system at equilibrium that is disturbed from the outside.

2. Variation in a designated orbit, as of a planet, that results from the influence of one or more external bodies. Gravitational attraction between planets can cause perturbations and cause a planet to deviate from its expected orbit. Perturbations in Neptune's orbit led to the discovery of the object—Pluto—that was causing the perturbation. Perturbations in the orbits of stars have led to the discovery of planetary systems outside of our Solar system.

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Other Word Forms

• perturbational adjective

Etymology

Origin of perturbation

1325–75; < Latin perturbātiōn- (stem of perturbātiō; perturb, -ation ); replacing Middle English perturbacioun < Anglo-French < Latin, as above

Example Sentences

"Standard computational studies of photocatalysts typically focus on ground-state properties and neglect excited-state effects, despite the fact that photocatalysis is inherently driven by photoexcited charge carriers. Specifically, we employ many-body perturbation theory methods."

From Science Daily • Mar. 16, 2026

But with 76 years of data to measure against, “we can provide the context needed to answer the question of, how big of a perturbation is this event?”

From Los Angeles Times • Jan. 29, 2025

Study participants were then tasked with responding to an "expected perturbation," meaning they had to respond to something that might throw off their balance.

From Science Daily • Oct. 18, 2023

While there, he studied a key node of the mammalian immune system — dendritic cells — and their perturbation in HIV/AIDS.

From Los Angeles Times • Oct. 2, 2023

The nearest star for which this gravitational perturbation method can be applied is Barnard’s Star, the nearest single star.

From "Cosmos" by Carl Sagan