FAQ: Can special relativity handle accelerated frames of reference? What is the distinction between special and general relativity? Einstein believed, erroneously, that the crucial difference between special and general relativity was that general relativity allowed accelerated frames of reference. In fact, it has been known for many decades that special relativity is capable of handling accelerated frames of reference.[Gourgoulhon] This can be done, for example, using coordinates popularized by Rindler,[Rindler] which were apparently known as far back as 1936.[Einstein] GR describes gravity as the curvature of spacetime. The correct modern definition of the distinction between SR and GR, universally agreed upon by modern relativists, is that SR deals with flat spacetime, GR with curved spacetime.[Carroll],[Wald] References Sean Carroll, Lecture Notes on General Relativity, ch. 1, "Special relativity and flat spacetime," http://ned.ipac.caltech.edu/level5/March01/Carroll3/Carroll1.html Einstein and Rosen, "A Particle Problem in the General Theory of Relativity," Physical Review 48 (1936) 73 Gourgoulhon, Special Relativity in General Frames: From Particles to Astrophysics, 2013 Rindler, Essential Relativity: Special, General, and Cosmological Wald, General Relativity, p. 60: "...the special theory of relativity asserts that spacetime is the manifold R^4 with a flat metric of Lorentz signature defined on it. Conversely, the entire content of special relativity ... is contained in this statement ..."