from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The act of perturbing.
  • n. The state of being perturbed; agitation.
  • n. A small change in a physical system.
  • n. Physics & Astronomy Variation in a designated orbit, as of a planet, resulting from the influence of one or more external bodies.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Agitation; the state of being perturbed
  • n. A small change in a physical system, or more broadly any definable system (such as a biological or economic system)
  • n. Variation in an orbit due to the influence of external bodies

from the GNU version of the Collaborative International Dictionary of English

  • n. The act of perturbing, or the state of being perturbed; esp., agitation of mind.
  • n. A disturbance in the regular elliptic or other motion of a heavenly body, produced by some force additional to that which causes its regular motion.

from The Century Dictionary and Cyclopedia

  • n. The act of perturbing, or the state of being perturbed; disturbance; disorder; especially, disquiet of mind; restlessness or want of tranquillity of mind; commotion of the passions.
  • n. Variation; especially, irregular or violent variation.
  • n. A cause of disquiet.
  • n. In astronomy, a deviation of the motion of a planet or comet from a fixed orbit or from its regular velocity in that orbit.
  • n.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a disposition that is confused or nervous and upset
  • n. (physics) a secondary influence on a system that causes it to deviate slightly
  • n. activity that is a malfunction, intrusion, or interruption
  • n. the act of causing disorder
  • n. an unhappy and worried mental state


from Wiktionary, Creative Commons Attribution/Share-Alike License

perturb + -ation


  • The interplanetary and relativistic corrections can be shown, to lowest order in perturbation theory, to result in the major axes of the planetary orbits precessing in space.

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  • A theoretically optimal system that blows up at the slightest perturbation is not a great real-world solution.

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  • A hundred years later, Laplace reduced the effects of the planets on each other to a series of 2 body problems and proved, at least to lowest order in perturbation theory, that the system was, in fact, stable over long periods of time (when questioned by Napoleon as to what influence god might have on the subject, Laplace famously replied that he had no need of that hypothesis).

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  • Holes appear only if a finite perturbation is applied to the layer for accelerations a above 10g.

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  • In games for which there exists a potential, the deviation-from-rationality dynamical model for which each agent's output follows the gradient of the potential along with a normally distributed random perturbation, is shown to equilibrate to a Gibbs measure.

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  • The tech bubble burst and 9/11 both resulted in significant short term perturbation of economic trend lines.

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  • He agreed to furnish dogs on a given date, but no sooner had Floyd Vanderlip turned his toes up-creek, than Charley hied himself away in perturbation to Loraine Lisznayi.

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  • (The simple law of inverse square does not apply, because a perturbation is a differential effect: the satellite or ocean when nearer to the perturbing body than the rest of the earth, is attracted more, and when further off it is attracted less than is the main body of the earth; and it is these differences alone which constitute the perturbation.)

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  • But when the perturbation was a little subsided, and men began to inquire why they were banded together, the difficulty of defining their purpose proved that the league, however respectable, was not a party.


  • The perturbation was a single extra 'spike', or nerve impulse, introduced to a single neuron in the brain of a rat. - latest science and technology news stories


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