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; see perturb, -ation); replacing Middle English perturbacioun < Anglo-French < Latin, as above

Explanation

When you're on an airplane with your friend who's terrified of flying, you'll be able to sense her perturbation, even if she doesn't say a word about how scared she is. The noun perturbation means "anxiety or uneasiness." Perturbation means "a state of agitation," or it can refer to whatever's causing the anxiety. Your brother's weird haircut could be the perturbation that's upsetting your mom at Thanksgiving dinner. It usually means a personal feeling of upset or nervousness, but perturbation can also be a physical disruption of some kind, like a perturbation in a river that makes the water become choppy and dangerous. In astronomy, perturbation is a change caused by the gravitational pull of a celestial body.

Example Sentences

The project, called the Stratospheric Controlled Perturbation Experiment, or SCoPEx, was necessary, the team argued, because it wasn’t clear whether existing computer simulations would truly align with a real-world scenario.

From Salon • Dec. 12, 2024

Perturbation exercises “don’t have to be complex, they just have to be challenging,” Wilk says.

From Washington Post • Jul. 5, 2021

Perturbation training engages the appropriate brain centers to reestablish proprioception skills.

From Washington Post • Jul. 5, 2021

The Stratospheric Controlled Perturbation Experiment, led by climate scientists at Harvard University, will test the idea in a small, controlled way.

From Science Magazine • Jan. 3, 2019

His desiring Marcellus to stop it, is also much in Nature, because it shews a Perturbation of Mind, very much to be expected at such an Incident.

From Some Remarks on the Tragedy of Hamlet, Prince of Denmark, Written by Mr. William Shakespeare (1736) by Anonymous