ABSTRACT
The month of November 1915 marks the birth of general relativity, and thus the birth of a new world, in the sense that Minkowski had used this word (die Welt): the world of space-time. Einstein’s new world is not, as had been believed for two thousand years, a rigid checkerboard on which matter and force play, without their game having any influence on the checkerboard which carries them. Instead, Einstein’s new world takes an active part in the game played by matter and force. The new game of the world is a game for four, that is to say space, time, matter, and force, or rather a game for two, space-time and mass-energy, where all the partners influence each other reciprocally. The mass-energy deforms space-time by its presence, and the deformed checkerboard of space-time determines the fashion in which mass-energy meanders through it.
