The period in Terragen Old Earth history initiated by the first use of the atomic bomb and characterized by atomic energy as a military, political, and industrial factor.
During this period, which lasted from 1945 to 1993, the world was divided into two superpowers, USA and USSR, both equipped with huge arsenals of nuclear weapons. With the exception of the Technocalypse, this was the closest humanity came to destroying itself and all other life on the planet. The atomic age was replaced by the Information Age (which is arbitrarily dated at the origination of the Terran World Wide Web) but nuclear weapons continued to remain a threat for many centuries to follow.