Crossword clues for perturbation
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Perturbation \Per`tur*ba"tion\, n. [L. perturbatio: cf. F. perturbation.]
The act of perturbing, or the state of being perturbed; esp., agitation of mind.
(Astron.) 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; as, the perturbations of the planets are caused by their attraction on each other.
--Newcomb.
Douglas Harper's Etymology Dictionary
late 14c., from Old French perturbacion "disturbance, confusion" (14c.) and directly from Latin perturbationem (nominative perturbatio) "confusion, disorder, disturbance," noun of action from past participle stem of perturbare (see perturb).
Wiktionary
n. 1 (context uncountable English) agitation; the state of being perturbed 2 (context countable English) A small change in a physical system, or more broadly any definable system (such as a biological or economic system) 3 (context countable astronomy physics English) Variation in an orbit due to the influence of external bodies
WordNet
n. an unhappy and worried mental state; "there was too much anger and disturbance"; "she didn't realize the upset she caused me" [syn: disturbance, upset]
(physics) a secondary influence on a system that causes it to deviate slightly
activity that is an intrusion or interruption; "he looked around for the source of the disturbance"; "there was a disturbance of neural function" [syn: disturbance]
a disposition that is confused or nervous and upset [syn: fluster]
the act of causing disorder [syn: disruption]
Wikipedia
In astronomy, perturbation is the complex motion of a massive body subject to forces other than the gravitational attraction of a single other massive body. The other forces can include a third (fourth, fifth, etc.) body, resistance, as from an atmosphere, and the off-center attraction of an oblate or otherwise misshapen body.
Perturbation (from Latin: perturbare "to confuse, disorder, disturb," from per- "through" + turbare "disturb, confuse," from turba "turmoil, crowd") is a set of Pedology (soil study) and sedimentary geology processes relating to changes in the nature of water-borne alluvial sediments and in situ soil deposits over time.
- Pedoturbation (from Greek: πέδον, pedon, "soil") involves mixing between soil horizons, and is an important factor in soil formation. Pedoturbation includes churning clays, cryoturbation, and bioturbation. Types of bioturbation include faunal pedoturbation (animal burrowing), and floral pedoturbation (root growth, tree-uprootings). Pedoturbation transforms soils through destratification, mixing, and sorting, as well as creating preferential flow paths for soil gas and infiltrating water. The zone of active bioturbation is termed the soil biomantle.
- Soil perturbation that is not pedoturbation. Precipitation of surface salts also causes localized disruption of soils. Because it does not result in mixing between soil horizons, it is not considered pedoturbation.
- In geology, bioturbation is the displacement and mixing of sediment particles (i.e. sediment reworking) and solutes (i.e. biologically-mediated irrigation) by benthic zone (bottom water) fauna (animals) or flora (plants). Activity of bacteria is yet another important cause of perturbation in the geological record. Field termites are especially important in tropical climate regions within 15° of the equator.
Perturbation or perturb may refer to:
- Perturbation theory, mathematical methods that give approximate solutions to problems that cannot be solved exactly
- Perturbation (geology), changes in the nature of alluvial deposits over time
- Perturbation (astronomy), alterations to an object's orbit—e.g., caused by gravitational interactions with other bodies
- Perturbation theory (quantum mechanics), a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one
- Perturbation (biology), an alteration of the function of a biological system, induced by external or internal mechanisms
- Perturbation (transport), operation of a transport system outside of timetable such that delays in arrival and departure from defined locations are present.
- Perturbation function, mathematical function which relates the primal and dual problems.
Usage examples of "perturbation".
Excellent in cases of sudden syncope or fainting, such as sometimes require the opening of windows, the dashing on of cold water, the cutting of stays, perhaps, with a scene of more or less tumultuous perturbation and afflux of clamorous womanhood.
But without some sketch of the Presidente, it is impossible fully to understand the perturbation of heart from which Pons suffered.
So they set up a flight plan for one synodic period later, muttering something about perturbation corrections.
I went out with a beating heart, though I could not explain my perturbation, for I did not feel guilty in any way towards Therese, save in that I had not answered the last letter she had written me from Naples, thirteen years ago.
And we know the circuitry and the autocrine perturbations to try, or we know which gene activity perturbations to try that will cause that cell to differentiate into a normal cell type or cause that cell to commit hara-kiri.
I could not have made it, had I not believed that it would be the means of drawing new readers to Boswell, and eventually of finding for them in the complete work what many have already found-- days and years of growing enlightenment and happy companionship, and an innocent refuge from the cares and perturbations of life.
When these thoughts had fully taken possession of Jones, they occasioned a perturbation in his mind, which, in a constitution less pure and firm than his, might have been, at such a season, attended with very dangerous consequences.
This subordination of the stream to the lake is surest to take place with those in whom pure mind most predominates, whose spirit is least roiled by the perturbation of the senses.
I looked at it, and such was the perturbation of my mind, that, though the miniature really represented me as of a cheerful and animated expression, I thought I beheld a dreadful and a threatening visage.
He forgets to smoke, looks at the fire and ponders, lets his pipe out, fills the breast of Mr. Bagnet with perturbation and dismay by showing that he has no enjoyment of tobacco.
From the reports of eyewitnesses it transpires that the seismic waves were accompanied by a violent atmospheric perturbation of cyclonic character.
All the planets revolved around both stars, an arrangement with enough perturbations to make hash out of a standard orbit calculation, and Ferrol gave silent thanks that the team out there had been thinking straight enough to include updated numbers with their tachyon distress call.
And when, in 1841, the great Charles Lyell traveled to America to give a series of lectures in Boston, sellout audiences of three thousand at a time packed into the Lowell Institute to hear his tranquilizing descriptions of marine zeolites and seismic perturbations in Campania.
Excellent in cases of sudden syncope or fainting, such as sometimes require the opening of windows, the dashing on of cold water, the cutting of stays, perhaps, with a scene of more or less tumultuous perturbation and afflux of clamorous womanhood.
To my surprise careful Clara was practicing anachronisms, declaiming about the planets around nearer stars detectable by perturbation of the stellar paths.