Principle of relativity those frames do not, in general experience, seem to abide by the same laws of physics. In classical physics, fictitious forces are used to describe acceleration in non-inertial reference frames. The special principle of relativity was first explicitly enunciated by Galileo Galilei in 1632 in his "Dialogue Concerning the Two Chief World Systems", using the metaphor of Galileo's ship. Newtonian mechanics added to the special principle several other concepts, including laws of motion, gravitation, and an assertion of an absolute time. When formulated in the context of these laws, the special principle of relativity states that the laws of mechanics
Theory of relativity 1915. The final form of general relativity was published in 1916. The term "theory of relativity" was based on the expression "relative theory" () used in 1906 by Planck, who emphasized how the theory uses the principle of relativity. In the discussion section of the same paper, Alfred Bucherer used for the first time the expression "theory of relativity" (). By the 1920s, the physics community understood and accepted special relativity. It rapidly became a significant and necessary tool for theorists and experimentalists in the new fields of atomic physics, nuclear physics, and quantum mechanics. By comparison, general relativity did