them to precisely measure any change in resistance. The circuit was then rotated through 90 degrees about its axis as the resistance was measured. Because the Lorentz–FitzGerald contraction is only in the direction of motion, from the point of view of the "Aether frame" the length of the coils depended on their angle with respect to their Aether velocity. Trouton and Rankine therefore believed that the resistance as measured in the rest frame of the experiment should change as the device was rotated. However their careful measurements showed no detectable change in resistance. This showed that if the Lorentz–FitzGerald contraction existed, it was not measurable in the rest frame of the object – only theories containing the complete Lorentz transformation, like special relativity, are still valid. See also History of special relativity References External links On the Electrodynamics of Moving Bodies Einstein's 1905 paper Electromagnetic phenomena in a system moving with any velocity smaller than that of light Lorentz's 1904 paper Tests of special relativity 1908 in science