Editing Luminiferous aether (section)

==Lorentz aether theory==
{{Main|Lorentz ether theory}}
Between 1892 and 1904, [[Hendrik Lorentz]] developed an electron–aether theory, in which he avoided making assumptions about the aether. In his model the aether is completely motionless, and by that he meant that it could not be set in motion in the neighborhood of ponderable matter. Contrary to earlier electron models, the electromagnetic field of the aether appears as a mediator between the electrons, and changes in this field cannot propagate faster than the speed of light. A fundamental concept of Lorentz's theory in 1895 was the "theorem of corresponding states" for terms of order v/c.<ref group=A name=lorb /> This theorem states that an observer moving relative to the aether makes the same observations as a resting observer, after a suitable change of variables. Lorentz noticed that it was necessary to change the space-time variables when changing frames and introduced concepts like physical [[length contraction]] (1892)<ref group=A name=lora /> to explain the Michelson–Morley experiment, and the mathematical concept of [[Relativity of simultaneity|local time]] (1895) to explain the [[aberration of light]] and the [[Fizeau experiment]]. This resulted in the formulation of the so-called [[Lorentz transformation]] by [[Joseph Larmor]] (1897, 1900)<ref group=A name=lara /><ref group=A name=larb /> and Lorentz (1899, 1904),<ref group=A name=lorc /><ref group=A name=lord /> whereby (it was noted by Larmor) the complete formulation of local time is accompanied by some sort of [[time dilation]] of electrons moving in the aether. As Lorentz later noted (1921, 1928), he considered the time indicated by clocks resting in the aether as "true" time, while local time was seen by him as a heuristic working hypothesis and a mathematical artifice.<ref group=A name=lore /><ref group=A name=lorf /> Therefore, Lorentz's theorem is seen by modern authors as being a mathematical transformation from a "real" system resting in the aether into a "fictitious" system in motion.<ref group=B name=miller /><ref group=B name=darrigol /><ref group=B name=jana />

The work of Lorentz was mathematically perfected by [[Henri Poincaré]], who formulated on many occasions the [[Principle of Relativity]] and tried to harmonize it with electrodynamics. He declared simultaneity only a convenient convention which depends on the speed of light, whereby the constancy of the speed of light would be a useful [[postulate]] for making the laws of nature as simple as possible. In 1900 and 1904<ref group=A name=poinca /><ref group=A name=poincb /> he physically interpreted Lorentz's local time as the result of clock synchronization by light signals. In June and July 1905<ref group=A name=poincc /><ref group=A name=poincd /> he declared the relativity principle a general law of nature, including gravitation. He corrected some mistakes of Lorentz and proved the Lorentz covariance of the electromagnetic equations. However, he used the notion of an aether as a perfectly undetectable medium and distinguished between apparent and real time, so most historians of science argue that he failed to invent special relativity.<ref group=B name=miller /><ref group=B name=pais /><ref group=B name=darrigol />