Tube Alloys was the code name of the United Kingdom's research-and-development programme, with participation from Canada, to develop nuclear weapons during the Second World War. A 1940 memorandum on the possibility of a nuclear weapon led to the formation early in the war of the MAUD Committee, chaired by George Thomson (pictured), which called for an all-out development effort. Due to the high costs and the potential threat from German bombers, Tube Alloys was subsumed into the Manhattan Project by the Quebec Agreement. The British contribution to the Manhattan Project was crucial, but the United States did not provide complete details to the United Kingdom. The Soviet Union gained valuable information through its atomic spies, who had infiltrated both the British and American projects. After the war, the United States terminated co-operation with the enactment of the Atomic Energy Act of 1946. This prompted the United Kingdom to relaunch its own project: High Explosive Research. (Full article...)