Paul Frees
Self - Narrator (voice)
Acting
Jon Else
Interviewer
Directing
J. Robert Oppenheimer
Self (archive footage)
Acting
Hans Bethe
Self
Acting
Frank Oppenheimer
Self
Acting
Haakon Chevalier
Self
Acting
Robert Serber
Self
Acting
Holm Bursom
Self
Acting
Stirling Colgate
Self
Acting
Freeman Dyson
Self
Acting
Susan Evans
Self
Acting
Francis Fergusson
Self
Acting
Leslie Groves
Self (archive footage)
Acting
Elizabeth Ingram
Self
Acting
Robert Krohn
Self
Acting
Dave MacDonald
Self
Acting
Joseph McCarthy
Self (archive footage)
Acting
Dorothy McKibben
Self
Acting
Robert Porton
Self
Acting
Isidor Isaac Rabi
Self
Acting
Harry S. Truman
Self (archive footage)
Acting
Francoise Ulam
Self
Acting
Stanislaw Ulam
Self
Acting
Jane Wilson
Self
Acting
Robert R. Wilson
Self
Acting