Is given convincing experimental proof of dependence of the sensitivity Michelson interferometer (MI) to the detection of velocity υ "aether wind" from relativistics structure of the refractive index n of the optical medium. Appeared, that sensitivity of instrument MI to detection υ is dependent from "inertial" of part of index (n²–1), induced by polarization particles. When in light-carrying medium MI is absent particles (n=1.), sensitivity to detection υ y MI is zero, since (n²–1)=0. Neglect of relativistic nature of the index (n²–1) in the interpretation of experiments on the MI cited (of those, who interpreted these experiments using the formula Michelson) to the underestimate the speed υ in 1./(n²–1.)^1/2 times. For air (n=1.0003) the value υ always was underestimated of a ~ 40–fold. In this nobody noticed error Michelson (including Lorentz, Einstein, and all, who agreed with them in 1927 at a conference in Pasadena) is the essence took place in the 20^th century of falsification experiments of Michelson type, as the alleged "negative". The latent of the form of relativistic structure (n²–1) still can not find a reasonable of classical of explanation phenomenon of the angular aberration of light rays in the experiment by Bradley.