Charles Regnier as I. Robert Oppenheimer

Hans Karl Friedrich as Ward V. Evans

Georg Peter-Pilz as Thomas A. Morgan

Siegfried Wischnewski as Roger Robb

Carl Lange as Gordon Gray

Konrad Georg as Herbert S. Marks

Hans Epskamp as Loyd K. Garrison

Franz Kutschera as Borris T. Pash

Friedrich Joloff as John Lansdale

Alexander Kerst as Edward Teller

Kaspar Brüninghaus as Hans Bethe

Heinz Frölich as David Tressel Griggs

Hanns Ernst Jäger as Isadore Isaac Rabi

Robert Freitag as Berichterstatter