Kirchhoff Sentence Examples
Taylor Jones showed in 1897 that only a small proportion of the contraction exhibited by a nickel wire when magnetized could be accounted for on Kirchhoff's theory from the observed effects of pulling stress upon magnetization; and in a more extended series of observations Nagaoka and Honda found wide quantitative divergences between the results of experiment and calculation, though in nearly all cases there was agreement as to quality.
They consider, however, that Kirchhoff's theory, which assumes change of magnetization to be simply proportional to strain, is still in its infancy, the present stage of its evolution being perhaps comparable with that reached by the theory of magnetization at the time when the ratio I/H was supposed to be constant.
Nagaoka and Honda have succeeded in showing that the observed relations between twist and magnetization are in qualitative agreement with an extension of Kirchhoff's theory of magnetostriction.
Kirchhoff's solution is obtained of a barrier placed obliquely in an infinite stream.
At first he occupied himself with ordinary routine work, but being far from satisfied with the scope which this afforded, he seized eagerly upon the opportunity for novel research, offered by Kirchhoff's discoveries in spectrum analysis.
C is a constant, equal to the coefficient of viscosity in Helmholtz's theory, but less simple in Kirchhoff's theory.
Though the experimental and theoretical developments were not necessarily dependent on each other, and by far the larger proportion of the subject which we now term " Spectroscopy " could stand irrespective of Gustav Kirchhoff's thermodynamical investigations, there is no doubt that the latter was, historically speaking, the immediate cause of the feeling of confidence with which the new branch of science was received, for nothing impresses the scientific world more strongly than just that little touch of mystery which attaches to a mathematical investigation which can only be understood by the few, and is taken on trust by the many, provided that the author is a man who commands general confidence.
While Balfour Stewart's work on the theory of exchanges was too easily understood and therefore too easily ignored, the weak points in Kirchhoff's developments are only now beginning to be perceived.
The investigations both of Balfour Stewart and of Kirchhoff are based on the idea of an enclosure at uniform temperature and the general results of the reasoning centre in the conclusion that the introduction of any body at the same temperature as the enclosure can make no difference to the streams of radiant energy which we imagine to traverse the enclosure.
This result, which, accepting the possibility of having an absolutely opaque enclosure of uniform temperature, was clearly proved by Balfour Stewart for the total radiation, was further extended by Kirchhoff, who applied it (though not with mathematical rigidity as is sometimes supposed) to the separate wave-lengths.Advertisement
All Kirchhoff's further conclusions are based on the assumption that the radiation transmitted through a partially transparent body can be expressed in term,s.
This is consistent with Kirchhoff's law and shows that the sodium in a flame possesses the same relative radiation and absorption as sodium vapour heated thermally to the temperature of the flames.
We might probably with advantage find some definition of what may be called " radiation temperature " based on the relation between radiation and absorption in Kirchhoff's sense, but further information based on experimental investigation is required.
The interpretation of spectroscopic observation seemed very simple when Kirchhoff and 1 Phil.
The same author proved that a sufficient thickness of layer raised the radiation to that of a black body in agreement with Kirchhoff's law.Advertisement
It is important to understand that Mach had developed this economical view of thought in 1872, more than ten years before the appearance of his work on the history of mechanics as he tells us in the preface, where he adds that at a later date similar views were expressed by Kirchhoff in his V orlesungen fiber mathematische Physik (1874).
Kirchhoff asserted that the whole object of mechanics is " to describe the motions occurring in Nature completely in the simplest manner."
It is evident that Kirchhoff's descriptive is the same as Mach's economical view.
In a word, Mach and Kirchhoff agree that force is not a cause, convert Newtonian reciprocal action into mere interdependency, and, in old terminology, reduce mechanics from a natural philosophy of causes to a natural history of mere facts.
Mach had begun to put them forward in 1872, and Kirchhoff in 1874.Advertisement
James Ward, in Naturalism and Agnosticism (1899), starts from the same phenomenalistic views of Mach and Kirchhoff about mechanics; he proceeds to the hypothesis of duality within experience, which we have traced in James Ward.
The relation follows immediately from Kirchhoff's expression (below, section 14) for the difference of vapour-pressure of the liquid and solid below the freezing-point.
The formula evidently applies to the vapour-pressure of the pure solvent as a special case, but Kirchhoff himself does not appear to have made this particular application of the formula.
Bunsen and Kirchhoff (Ann., 1860, 113, p. 337), in the spectroscopic examination of the residues obtained on evaporation of water from a mineral spring at Diirkheim, being characterized by two distinctive red lines.
Kirchhoff of Berlin.2 According to Kirchhoff, the Odyssey as we have it is the result of additions made to an original nucleus.Advertisement
The first of these representations is evidently natural, considering the twenty eventful years that have passed; but the second, Kirchhoff holds, is the Ulysses of Calypso's 1 On this point see a paper by Professor Packard in the Trans.
Ingenious as this is, there is really very slender ground for Kirchhoff's thesis.
The arguments by which Kirchhoff seeks to prove that the stories of books x.-xii.
Kirchhoff argues that the Artacia of the Argonautic story must have been taken from the real Artacia, and the Artacia of the Odyssey again from that of the Argonautic story.
Finally, when Kirchhoff finds traces in books x.-xii.
Inquiries conducted with the refinement which characterizes those of Kirchhoff are always instructive, and his book contains very many just observations; but it is impossible to admit his main conclusions.
Kirchhoff determined experimentally in a certain case the absolute value of the current induced by one circuit in another, and in the same year Erik Edland (1819-1888) made a series of careful experiments on the induction of electric currents which further established received theories.
As is shown by his verses and sometimes by his prose, his mind was highly imaginative; the poet Coleridge declared that if he "had not been the first chemist, he would have been the first poet 1 Davy's will directed that this service, after Lady Davy's death, should pass to his brother, Dr John Davy, on whose decease, if he had no heirs who could make use of it, it was to be melted and sold, the proceeds going to the Royal Society" to found a medal to be given annually for the most important discovery in chemistry anywhere made in Europe or Anglo-America."The silver produced £736, and the interest on that sum is expended on the Davy medal, which was awarded for the first time in 1877, to Bunsen and Kirchhoff for their discovery of spectrum analysis.
Kirchhoff's contributions to mathematical physics were numerous and important, his strength lying in his powers of stating a new physical problem in terms of mathematics, not merely in working out the solution after it had been so formulated.
Kirchhoff in announcing that the lines of the spectrum were characteristic of the chemical substance which emitted them, and in indicating the value of this discovery in chemical analysis.
The " black body " is an ideal body with surface so constituted as to reflect no part of any radiations that fall upon it; in the case of such a body Kirchhoff and Balfour Stewart showed that unless energy were to be lost the rate of emission and absorption must be in fixed ratio for each specific wave-length.
Kirchhoff's principle, accordingly, not only afforded a simple explanation of the Fraunhofer lines, but availed to found a far-reaching science of celestial chemistry.
But it was the K synthetic genius of Gustav Kirchhoff which first gave unity to the scattered phenomena, and finally reconciled what was appendages to the sun disclosed by it were such as eclipses.
He observed, in 1823, dark lines in stellar spectra which Kirchhoff's discovery supplied the means of interpreting.
Kirchhoff's second law A low-density gas will radiate an emission-line spectrum with an underlying emission continuum.
The first edition, with a full commentary based on scientific principles, was that of Aufrecht and Kirchhoff in 1849-1851, and on this all subsequent interpretations are based (Breal, Paris, 1875; Bucheler, Umbrica, Bonn, 1883, a reprint and enlargement of articles in Fleckeisen's Jahrbuch, 18 75, pp. 127 and 313).
In the case of this one force we know far more than the interdependence supposed by Mach and Kirchhoff; we know bodies with impenetrable force causing one another to keep apart.