Editing History of physics (section)

====General relativity====
{{further|History of general relativity}}
By 1916, Einstein was able to generalize this further, to deal with all states of motion including non-uniform acceleration, which became the general theory of relativity. In this theory, Einstein also specified a new concept, the curvature of space-time, which described the gravitational effect at every point in space. The curvature of space-time replaced Newton's universal law of gravitation. According to Einstein, gravitational force in the normal sense is an illusion caused by the geometry of space. The presence of a mass causes a curvature of space-time in the vicinity of the mass, and this curvature dictates the space-time path that all freely-moving objects follow. It was also predicted from this theory that light should be subject to gravity&nbsp;– all of which was verified experimentally. This aspect of relativity explained the phenomena of light bending around the sun, predicted black holes as well as properties of the [[Cosmic microwave background radiation]]&nbsp;– a discovery rendering fundamental anomalies in the classic Steady-State hypothesis. For his work on relativity, the photoelectric effect and blackbody radiation, Einstein received the Nobel Prize in 1921.

The gradual acceptance of Einstein's theories of relativity and the quantized nature of light transmission, and of [[Niels Bohr's model of the atom]] created as many problems as they solved, leading to a full-scale effort to reestablish physics on new fundamental principles. Expanding relativity to cases of accelerating reference frames (the "[[general relativity|general theory of relativity]]") in the 1910s, Einstein posited an equivalence between the inertial force of acceleration and the force of gravity, leading to the conclusion that space is curved and finite in size, and the prediction of such phenomena as [[gravitational lens]]ing and the distortion of time in gravitational fields.