2 8 4 D O C U M E N T 1 5 7 J A N U A R Y 1 9 2 6 See Doc. 13 for Einstein’s comments to the journal Science on the results of Dayton C. Miller’s ether drift experiments. See Michelson and Gale 1925, in which a ring interferometer is used to measure the rotation of the Earth. See Sagnac 1913 for the first experiment with a ring interferometer to report the Sagnac effect.The Sagnac effect invalidates the hypothesis of ether drag and was Miller’s preferred explana- tion of his own results (because, if the Earth indeed were to drag the ether along with it, it should be impossible to detect the Earth’s rotation). Émile Meyerson. See Doc. 9.