Group photograph of members of the Chicago Pile-1 – the world’s first artificial nuclear reactor – at the University of Chicago on 2 December 1946, marking the 4th anniversary of the pile reaching criticality.
Back row, from left: Norman Hilberry, Samuel Allison, Thomas Brill, Robert Nobles, Warren Nyer, and Marvin Wilkening. Middle row: Harold Agnew, William Sturm, Harold Lichtenberger, Leona Woods and Leó Szilárd.
Front row: Enrico Fermi, Walter Zinn, Albert Wattenberg and Herbert L. Anderson.
