“One of the greatest achievements in the history of human thought. It is not the discovery of an outlying island but of a whole continent of new scientific ideas.”—J. J. Thomson, Nobel laureate and president of the Royal Society

After a decade of strenuous effort, Einstein succeeded in generalizing his theory of relativity from the special case of bodies in uniform motion to describe all motion, including bodies in accelerated motion. Having completed his general theory of relativity by the end of 1915, Einstein published the finalized theory in the April 1916 issue of Annalen der Physik and in a separate printing, shown here.

According to general relativity, gravity is not Newton’s mysterious force acting instantaneously between distant bodies; it’s the acceleration of mass resulting from how bodies travel naturally through the curvature in spacetime they create.

Einstein’s new theory was a brilliant leap of imagination, developed through a secure grounding in the mathematics of tensor calculus and Riemannian geometry. The “field equations” Einstein ultimately created for his general theory described the contours of spacetime and the behavior of matter within it. According to the theory of  general relativity, the American theoretical physicist John Wheeler observed, “Mass tells space-time how to curve, and space-time tells mass how to move.”

The implications of his revolutionary theory were astounding. The principles of general relativity extended to the behavior of the entire universe. It helped explain the motion of planets and the formation of black holes. It provided evidence for the Big Bang, predicted the existence of gravitational waves and gravitational lensing, and has been essential in practical applications, such as modern GPS systems.

Einstein was aware of the profound power of his new theory. In a letter to his good friend Michele Besso in late 1915, he triumphantly announced that his “boldest dreams have now been fulfilled.”

 

Learn more about Einstein: The Man And His Mind.