It all began on cold mooring in New Mexico when the first atomic bomb was tested and since this is a known date it is also used in the ability to calculate by radio-carbon dating since every place on earth has remnants of this blast. From this point the bombs were dropped on Hiroshima and Nagasaki Japan, then the cold war, the nicker testing through out the 50, 60 and even today with the recent threats we are faced with today. This also is not the only as there have numerous power plants, Three Mile Island, Chernobyl so it is every where even the waste of the atom will outlive all of the living today on earth!