{"product_id":"2940015113563","title":"From the Works of Edward W. Morley Albert A. Michelson and Dayton C. Miller","description":"CONTENTS\u003cbr\u003e\u003cbr\u003eInfluence of Motion of the Medium on the Velocity of Light\u003cbr\u003eOn the Relative Motion of the Earth and the Luminiferous Ether\u003cbr\u003eExtract From a Letter Dated Cleveland, Ohio, August 5th, 1904, to Lord Kelvin from Profs. Edward W. Morley and Dayton C. Miller\u003cbr\u003eOn the Theory of Experiments to detect Aberrations of the Second Degree\u003cbr\u003eReport of an Experiment to Detect the Fitzgerald-Lorentz Effect\u003cbr\u003eFinal Report on Ether-drift Experiments\u003cbr\u003e\u003cbr\u003e***\u003cbr\u003e\u003cbr\u003eAn excerpt from:\u003cbr\u003e\u003cbr\u003eOn the Relative Motion of the Earth and the Luminiferous Ether\u003cbr\u003eAmerican Journal of Science, 1887, 34 (203): 333–345\u003cbr\u003e\u003cbr\u003e(Edward Morley and Albert Abraham Michelson)\u003cbr\u003e\u003cbr\u003eTHE discovery of the aberration of light was soon followed by an explanation according to the emission theory. The effect was attributed to a simple composition of the velocity of light with the velocity of the earth in its orbit. The difficulties in this apparently sufficient explanation were overlooked until after an explanation on the undulatory theory of light was proposed. This new explanation was at first almost as simple as the former. But it failed to account for the fact proved by experiment that the aberration was unchanged when observations were made with a telescope filled with water. For if the tangent of the angle of aberration is the ratio of the velocity of the earth to the velocity of light, then, since the latter velocity in water is three-fourths its velocity in a vacuum, the aberration observed with a water telescope should be four-thirds of its true value.*\u003cbr\u003e\u003cbr\u003e* It may be noticed that most writers admit the sufficiency of the explanation according to the emission theory of light; while in fact the difficulty is even greater than according to the undulatory theory. For on the emission theory the velocity of light must be greater in the water telescope, and therefore the angle of aberration should be less; hence, in order to reduce it to its true value, we must make the absurd hypothesis that the motion of the water in the telescope carries the ray of light in the opposite direction! \u003cbr\u003e\u003cbr\u003eOn the undulatory theory, according to Fresnel, first, the ether is supposed to be at rest except in the interior of transparent media, in which secondly, it is supposed to move with a velocity less than the velocity of the medium in the ratio n2-1\/ n2 , where n is the index of refraction. These two hypotheses give a complete and satisfactory explanation of aberration. The second hypothesis, notwithstanding its seeming improbability, must be considered as fully proved, first, by the celebrated experiment of Fizeau,  Influence of Motion of the Medium on the Velocity of Light. This Journal, III, xxxi, 377, 1886.  and secondly, by the ample confirmation of our own work. The experimental trial of the first hypothesis forms the subject of the present paper.\u003cbr\u003eIf the earth were a transparent body, it might perhaps be conceded, in view of the experiments just cited, that the inter-molecular ether was at rest in space, notwithstanding the motion of the earth in its orbit; but we have no right to extend the conclusion from these experiments to opaque bodies. But there can hardly be question that the ether can and does pass through metals. Lorentz cites the illustration of a metallic barometer tube. When the tube is inclined the ether in the space above the mercury is certainly forced out, for it is imcompressible.* But again we have no right to assume that it makes its escape with perfect freedom, and if there be any resistance, however slight, we certainly could not assume an opaque body such as the whole earth to offer free passage through its entire mass. But as Lorentz aptly remarks: \"quoi qu’il en soit, on fera bien, à mon avis, de ne pas se laisser guider, dans une question aussi importante, par des considérations sur le degré de probabilité ou de simplicité de l’une ou de l’autre hypothèse, mais de s’addresser a l’expérience pour apprendre à connaitre l’état, de repos ou de mouvement, dans lequel se trouve l’ether à la surface terrestre.\"\u003cbr\u003e* It may be objected that it may escape by the space between the mercury and the walls; but this could be prevented by amalgamating the walls.\u003cbr\u003e\u003cbr\u003eIn April, 1881, a method was proposed and carried out for testing the question experimentally.*\u003cbr\u003e\u003cbr\u003e* The Relative Motion of the Earth and the Luminiferous Ether, by Albert A. Michelson, this Jour., III xxii, 120. \u003cbr\u003e\u003cbr\u003eIn deducing the formula for the quantity to be measured, the effect of the motion of the earth through the ether on the path of the ray at right angles to this motion was overlooked. The discussion of this oversight and of the entire experiment forms the subject of a very searching analysis by H. A. Lorentz,  who finds that this effect can by no means be disregarded.","brand":"OGB","offers":[{"title":"Default Title","offer_id":47074086256880,"sku":"2940015113563","price":0.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0737\/7593\/9824\/files\/2940015113563_p0.jpg?v=1763619047","url":"https:\/\/shop-qa.barnesandnoble.com\/products\/2940015113563","provider":"Barnes \u0026 Noble (DEV)","version":"1.0","type":"link"}