Chicago Pile-1 Chicago Pile-1 Chicago Pile-1 (CP-1) was the world's first nuclear reactor. On 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated in CP-1, during an experiment led by Enrico Fermi. The reactor's development was part of the Manhattan Project, the Allied effort to create atomic bombs during World War II. It was built by the Metallurgical Laboratory at the University of Chicago, under the west viewing stands of the original Stagg Field. Fermi described the apparatus as "a crude pile of black bricks and wooden timbers". The reactor was assembled in November 1942, by a team that
Enrico Fermi and on the weight of electromagnetic charges" ('). Using general relativity, Fermi showed that a charge has a weight equal to U/c, where U was the electrostatic energy of the system, and c is the speed of light. The first paper seemed to point out a contradiction between the electrodynamic theory and the relativistic one concerning the calculation of the electromagnetic masses, as the former predicted a value of 4/3 U/c. Fermi addressed this the next year in a paper "Concerning a contradiction between electrodynamic and the relativistic theory of electromagnetic mass" in which he showed that the apparent contradiction