Perturbations Sentence Examples
It has not indeed proved practically available; but his system of calculating cometary perturbations by means of "mechanical quadratures" has formed the startingpoint of all subsequent researches on the subject.
This law has important ethical and political bearings; but in the province of disease this advance of what may be compared to the interlocking of points and signals has had wide influence not only in altering our conceptions of disease, but also in enlarging our views of all perturbations of function.
The manuscript residue includes papers on atmospheric refraction (dated 1755), on the motion of Mars as affected by the perturbations of Jupiter and the Earth (1756), and on terrestrial magnetism (1760 and 1762).
This is not inconsistent with the law of gravitation, for such estimates as have been made of planetary perturbations due to stars give results which are insignificant in comparison with quantities at present measurable.
As practically attacked it consists in the problem of determining the perturbations or disturbances in the motion of one of the bodies around the principal or central body, produced by the attraction of the third.
When one or more other bodies form a part of the system, their action produces deviations from the elliptic motion, which are called perturbations.
The prize was again awarded to Lagrange; and he earned the same distinction with essays on the problem of three bodies in 1772, on the secular equation of the moon in 1774, and in 1778 on the theory of cometary perturbations.
The discordance of their results incited Laplace to a searching examination of the whole subject of planetary perturbations, and his maiden effort was rewarded with a discovery which constituted, when developed and completely demonstrated by his own further labours and those of his illustrious rival Lagrange, the most important advance made in physical astronomy since the time of Newton.
Many of the symptoms of diseases were caused by the passions and perturbations of the archeus, and medicines acted by modifying the ideas of the same archeus.
Thus it came about not only that classifications of disease based on superficial likeness - such as jaundice, dropsy, inflammation - were broken up, and their parts redistributed, but also that even more set diseases began to lose their settlements, and were recognized as terms of series, as transitory or culminating phases of perturbations which might be traced to their origins, and in their earlier stages perhaps withstood.
AdvertisementMany other diseases formerly regarded as primarily diseases of the nervous system are not such; but, by means of agents either introduced into the body or modified there, establish themselves after the affinities of these in contiguous associated parts of the structure, as in vascular, membranous or connective elements, or again in distant and peripheral parts; the perturbations of nervous function being secondary and consequential.
After a rough estimate of the perturbations it must sustain from the attraction of the planets, he predicted its return for 1757,-a bold prediction at that time, but justified by the event, for the comet again made its appearance as was expected, though it did not pass through its perihelion till the month of March 1759, the attraction of Jupiter and Saturn having caused, as was computed by Clairault previously to its return, a retardation of 618 days.
That entitled Developpemens sur diferents points de la theorie des perturbations (1841), was translated in part xviii.
His first work on this abstruse subject, entitled T heorie des perturbations de la lune, qui sont dues a faction des planetes,1 is remarkable for the boldness of its conception, and constitutes an important addition to celestial dynamics.
From the motion of the satellites he finds that the mass of Uranus is - T - A o o th of that of the sun, while for the planet Neptune he finds a mass equal to 19 Toth of the sun, agreeing with the value previously found by him from the perturbations of Uranus within o th of its amount.
AdvertisementThe sun is a small target for a meteorite coming from infinity to hit, and if this considerable quantity reaches its mark, a much greater amount will circulate round the sun in parabolas, and there is no evidence of it where it would certainly make itself felt, in perturbations of the planets.
Using a powerful and elaborate analysis, Adams ascertained that this cluster of meteors, which belongs to the solar system, traverses an elongated ellipse in 334 years, and is subject to definite perturbations from the larger planets, Jupiter, Saturn and Uranus.
But when definitive results as to the orbits are required, it is necessary to compute the perturbations produced by such of the major planets as have affected the motions of the body.
The principal modification is that,up to the present time, stellar astronomy has not advanced so far that a computation of the perturbations in each case of a system of stars is either necessary or possible, except in exceptional cases.
The problem of determining the perturbations of the (2) Q heavenly bodies is perhaps the most complicated with which the mathematical astronomer has to grapple; and the forms under which it has to be studied are so numerous that they cannot be easily arranged under any one head.
AdvertisementThe problem of determining the changes is, however, simpler than others in perturbations.
The practical methods of computing perturbations of the planets and satellites were first exhaustively developed by Pierre Simon Laplace in his Mecanique celeste.
The subject of planetary perturbations was next attacked.
The prize of the Berlin Academy was, in 1780, adjudged to Lagrange for a treatise on the perturbations of comets; and he contributed to the Berlin Memoirs, 1781-1784, a set of five elaborate papers, embodying and unifying his perfected methods and their results.
The discovery of Neptune in 1846 by Adams and Leverrier marked the first solution of the " inverse problem " of perturbations.
AdvertisementAmong the fruits of the strenuous career of Nicolas Louis de Lacaille were tables of the sun, in which terms depending upon planetary perturbations were, for the first time, introduced (1758); an extended acquaintance with the southern heavens; and a determination of the moon's parallax from observations made at opposite extremities of an arc of the meridian 85' in length.
The oscillation of the centre of power between Meath and Tir Eogain, according as the ardri belonged to the southern or northern Hy Neill, produced corresponding perturbations in the balance of parties among the minor kings.
A research into the mutual perturbations of Jupiter and Saturn secured for him the prize of the Berlin Academy in 1830, and a memoir on cometary disturbances was crowned by the Paris Academy in 1850.
He shows that, supposing the cloud of particles to move around the sun in nearly circular orbits immediately outside the earth, the perturbations by the earth in the motion of the particles will result in their retardation in that part of the orbit nearest the earth, and therefore in their always being more numerous in a given space in this part of the orbit Ethan in any other.
One sees the imprint of these primordial fluctuations as small temperature perturbations in the cosmic microwave background radiation.
This has an effect on the two-point correlation function of the perturbations, but it seems to be quite small.
Without applying external perturbations at the inflow boundary, large vortical structures develop naturally in the flow field due to buoyancy effects.
Resonance A state in which an orbiting object is subject to periodic gravitational perturbations by another.
In these exposures the atmospheric phase perturbations are compensating for the errors in the figure of the telescope mirror.
Subtle exponentially small effects result from singular perturbations implicit in certain multiple time scale systems.
The probability for the tensor perturbations will peak at order ten to the minus eight.
Generally, however, there is no correlation with either native state shift perturbations or with sequence proximity to aromatic groups.
Initial runs with a " slab " (thermodynamic ocean) version will help prioritize parameter perturbations.
In his Recherches sur differents points importants du systeme du monde (1754-1756) he perfected the solution of the problem of the perturbations of the planets, which he had presented to the academy some years before.
In any case the orbits of comets are exposed to such tremendous perturbations from the planets that it is unsafe from the present orbit of a comet to conjecture what that orbit may have been in remote antiquity.
By his researches on the migration of the white corpuscles of the blood Cohnheim, on the bases laid by Virchow, brought the processes of inflammation within the scope of the normal, seeing in them but a modification of normal processes under perturbations of relatively external incidence; even the formation of abscess was thus brought by him within the limits of perversion of processes not differing essentially from those of health; and "new formations," "plastic exudations," and other discontinuous origins of an "essential" pathology, fell into oblivion.
But there is one conception of perturbations of such generality and elegance that it forms the common base of all those methods of determining these deviations which have high scientific interest.
The velocity of resonant drift, produced by spatially uniform perturbations is obtained.