Learn more here. In 1942, the Manhattan Project needed to create a chain reaction—a crucial step toward proving that it would be possible to make an atomic bomb. The scientists achieved this sustained ...

The clock hands are set by the Bulletin of the Atomic Scientists, a group formed by Manhattan Project scientists at the University of Chicago who helped build the atomic bomb but protested using it ...

Barack Obama is the first American president to visit Hiroshima since the nuclear attack on the city. In his speech in May ...

A photo supposedly showing the "atomic shadow" of a human and a ladder that was created when the U.S. dropped atomic bombs above Japan at the end of World War II has been frequently shared online ...