The Chicago blog farkleberries reminds us that today is a solemn day in Chicago history: on December 2, 1942, at the University of Chicago, physicist Enrico Fermi and scientists from his laboratory achieved the first controlled nuclear fission chain reaction, which led to the creation of the atomic bomb and nuclear power plants. At the Library of Congress' Today In History page, they've got some related scanned documents and photographs, as well as a bunch of links guaranteed to help you kill the last hour of work.