Changes

" The [[hypothesis]] of an aether has been maintained by [[different]] speculators for very different [[reasons]]. To those who [[maintained]] the [[existence]] of a plenum as a philosophical principle, [[nature]]'s abhorrence of a [[vacuum]] was a sufficient [[reason]] for ''imagining'' an all-surrounding aether, even though every other [[argument]] should be against it. To [http://en.wikipedia.org/wiki/Descartes Descartes], who made extension the sole [[essential]] property of [[matter]], and matter a [[necessary]] condition of extension, the bare existence of bodies [[apparently]] at a distance was a [[proof]] of the existence of a [[continuous]] [[medium]] between them. But besides these high [[metaphysical]] necessities for a medium, there were more mundane uses to be fulfilled by aethers. Aethers were [[invented]] for the [[planets]] to swim in, to [[constitute]] [[electric]] [[atmosphere]]s and [[magnetic]] effluvia, to convey sensations from one part of our bodies to another, and so on, till all [[space]] had been filled three or four times over with aethers. It is only when we remember the extensive and mischievous [[influence]] on [[science]] which [[hypotheses]] about aethers used formerly to [[exercise]], that we can appreciate the horror of aethers which sober-minded men had during the [http://en.wikipedia.org/wiki/18th_Century 18th century], and which, probably as a sort of hereditary [[prejudice]], descended even to [http://en.wikipedia.org/wiki/John_Stuart_Mill John Stuart Mill]. The [[disciples]] of [http://en.wikipedia.org/wiki/Isaac_Newton Newton] [[maintained]] that in the [[fact]] of the [[mutual]] [[gravitation]] of the heavenly bodies, according to Newton's law, they had a complete [[quantitative]] account of their [[motions]]; and they endeavoured to follow out the path which Newton had opened up by [[investigating]] and [[measuring]] the [[attractions]] and repulsions of [[electrified]] and [[magnetic]] bodies, and the cohesive [[forces]] in the interior of bodies, without attempting to account for these [[forces]]. Newton himself, however, endeavoured to account for [[gravitation]] by [[differences]] of [[pressure]] in an aether; but he did not publish his [[theory]], ` because he was not able from [[experiment]] and [[observation]] to give a satisfactory account of this [[medium]], and the [[manner]] of its operation in producing the chief [[phenomena]] of [[nature]].' On the other hand, those who imagined aethers in order to explain [[phenomena]] could not specify the [[nature]] of the motion of these media, and could not ''prove'' that the media, as imagined by them, would produce the [[effects]] they were meant to explain. The only aether which has [[survived]] is that which was [[invented]] by [http://en.wikipedia.org/wiki/Christiaan_Huygens Huygens] to explain the propagation of [[light]]. The [[evidence]] for the [[existence]] of the luminiferous aether has accumulated as additional [[phenomena]] of [[light]] and other [[radiation]]s have been [[discovered]]; and the properties of this medium, as deduced from the phenomena of light, have been found to be precisely those required to explain [[electromagnetic]] [[phenomena]]." This description, quoted from [http://en.wikipedia.org/wiki/James_Clark_Maxwell James Clerk Maxwell]'s article in the 9th edition of the Encyclopaedia Britannica, [[represents]] the historical position of the subject up till about 1860, when Maxwell began those constructive speculations in [[electrical]] [[theory]], based on the [[influence]] of the physical views of [http://en.wikipedia.org/wiki/Michael_Faraday Faraday] and [http://en.wikipedia.org/wiki/Lord_Kelvin Lord Kelvin], which have in their subsequent [[development]] largely transformed theoretical [[physics]] into the [[science]] of the ''aether''.[http://www.1911encyclopedia.org/Aether]

" The [[hypothesis]] of an aether has been maintained by [[different]] speculators for very different [[reasons]]. To those who [[maintained]] the [[existence]] of a plenum as a philosophical principle, [[nature]]'s abhorrence of a [[vacuum]] was a sufficient [[reason]] for ''imagining'' an all-surrounding aether, even though every other [[argument]] should be against it. To [http://en.wikipedia.org/wiki/Descartes Descartes], who made extension the sole [[essential]] property of [[matter]], and matter a [[necessary]] condition of extension, the bare existence of bodies [[apparently]] at a distance was a [[proof]] of the existence of a [[continuous]] [[medium]] between them. But besides these high [[metaphysical]] necessities for a medium, there were more mundane uses to be fulfilled by aethers. Aethers were [[invented]] for the [[planets]] to swim in, to [[constitute]] [[electric]] [[atmosphere]]s and [[magnetic]] effluvia, to convey sensations from one part of our bodies to another, and so on, till all [[space]] had been filled three or four times over with aethers. It is only when we remember the extensive and mischievous [[influence]] on [[science]] which [[hypotheses]] about aethers used formerly to [[exercise]], that we can appreciate the horror of aethers which sober-minded men had during the [http://en.wikipedia.org/wiki/18th_Century 18th century], and which, probably as a sort of hereditary [[prejudice]], descended even to [http://en.wikipedia.org/wiki/John_Stuart_Mill John Stuart Mill]. The [[disciples]] of [http://en.wikipedia.org/wiki/Isaac_Newton Newton] [[maintained]] that in the [[fact]] of the [[mutual]] [[gravitation]] of the heavenly bodies, according to Newton's law, they had a complete [[quantitative]] account of their [[motions]]; and they endeavoured to follow out the path which Newton had opened up by [[investigating]] and [[measuring]] the [[attractions]] and repulsions of [[electrified]] and [[magnetic]] bodies, and the cohesive [[forces]] in the interior of bodies, without attempting to account for these [[forces]]. Newton himself, however, endeavoured to account for [[gravitation]] by [[differences]] of [[pressure]] in an aether; but he did not publish his [[theory]], ` because he was not able from [[experiment]] and [[observation]] to give a satisfactory account of this [[medium]], and the [[manner]] of its operation in producing the chief [[phenomena]] of [[nature]].' On the other hand, those who imagined aethers in order to explain [[phenomena]] could not specify the [[nature]] of the motion of these media, and could not ''prove'' that the media, as imagined by them, would produce the [[effects]] they were meant to explain. The only aether which has [[survived]] is that which was [[invented]] by [http://en.wikipedia.org/wiki/Christiaan_Huygens Huygens] to explain the propagation of [[light]]. The [[evidence]] for the [[existence]] of the luminiferous aether has accumulated as additional [[phenomena]] of [[light]] and other [[radiation]]s have been [[discovered]]; and the properties of this medium, as deduced from the phenomena of light, have been found to be precisely those required to explain [[electromagnetic]] [[phenomena]]." This description, quoted from [http://en.wikipedia.org/wiki/James_Clark_Maxwell James Clerk Maxwell]'s article in the 9th edition of the Encyclopaedia Britannica, [[represents]] the historical position of the subject up till about 1860, when Maxwell began those constructive speculations in [[electrical]] [[theory]], based on the [[influence]] of the physical views of [http://en.wikipedia.org/wiki/Michael_Faraday Faraday] and [http://en.wikipedia.org/wiki/Lord_Kelvin Lord Kelvin], which have in their subsequent [[development]] largely transformed theoretical [[physics]] into the [[science]] of the ''aether''.[http://www.1911encyclopedia.org/Aether]

 

[[Category: History]]

[[Category: History]]

[[Category: Physics]]

[[Category: Physics]]