Special relativity to a first observer O, and frame S′ (pronounced "S prime") belongs to a second observer O′. Since there is no absolute reference frame in relativity theory, a concept of 'moving' doesn't strictly exist, as everything is always moving with respect to some other reference frame. Instead, any two frames that move at the same speed in the same direction are said to be "comoving". Therefore, "S" and "S"′ are not "comoving". The principle of relativity, which states that physical laws have the same form in each inertial reference frame, dates back to Galileo, and was incorporated into Newtonian physics.
Relativity priority dispute but not in connection with the Lorentz transformation, the relativity principle or the synchronisation procedure by light signals. However, in the last years before his death Einstein acknowledged some of Poincaré's contributions (according to Darrigol, maybe because his biographer Pais in 1950 sent Einstein a copy of Poincarè's Palermo paper, which he said that he had not read before). Einstein wrote in 1953: Kip Thorne concludes, in remarks based on Hilbert's 1924 paper, that Hilbert regarded the General Theory of relativity as Einstein's: "Quite naturally, and in accord with Hilbert's view of things, the resulting law of warpage was quickly