perturbation

[ pur-ter-bey-shuhn ]

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.

perturbation

/ 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

perturbation

/ 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.

Other Words From

• pertur·bation·al adjective

Word History and Origins

Origin of perturbation¹

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

Example Sentences

These perturbations make the stars’ orbits around the galactic center more and more elliptical.

From Science News

As the core wobbles, it creates gravitational perturbations that affect the surrounding rings, creating subtle “waves” that can be measured.

From MIT Technology Review

Called LowKey, the tool expands on Fawkes by applying perturbations to images based on a stronger kind of adversarial attack, which also fools pretrained commercial models.

From MIT Technology Review

Confronted with any perturbations, the model should be able to correct itself as well.

From MIT Technology Review

The fish used its swordlike snouts to sense electrical perturbations made by smaller prey.

From Science News For Students

He turned his thesis into the book Geometric Perturbation Theory in Physics on the new developments in differential geometry.

From The Daily Beast

Say your portfolio is worth a third less than before this recession or crash or perturbation or whatever you want to call it.

From The Daily Beast

At times there are periodic attacks of mental perturbation that may become true insanity.

From Project Gutenberg

She picked up her parasol, and resumed her journey in some perturbation of mind, reflecting on the utter rudeness of the deer.

From Project Gutenberg

I had an idea that she would shrink from me or show some perturbation; but I was never more mistaken in my life.

From Project Gutenberg

Agatha went up to her mistress in a state of great perturbation, and the cook also hurried away to her bedroom.

From Project Gutenberg

The frown of bewilderment was deeper now––the perturbation turned anxious.

From Project Gutenberg