Los Angeles, Dec 19 : The first full trailer for Christopher Nolan's 'Oppenheimer' film has dropped, with Cillian Murphy starring in the epic thriller based on the creation of the first atomic bomb. Murphy plays J. Robert Oppenheimer, the American theoretical physicist credited as the "father of the atomic bomb". The film directed and written by Nolan is based on the biography, "American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer", by Kai Bird and Martin J. Sherwin, reports 'Deadline'. "We imagine a future and our imaginings horrifiers. They would fear it until they understand it, and they won't understand it until they've used it," Murphy's Oppenheimer says in the trailer. "Theory will only take you so far. I don't know if we can be trusted with such a weapon but we have no choice." Other cast members include Emily Blunt, Florence Pugh, Robert Downey Jr., Matt Damon, Rami Malek, Benny Safdie, Josh Hartnett, Dane DeHaan, Jack Quaid, Matthew Modine, Dylan Arnold, David Krumholtz, Alden Ehrenreich, David Dastmalchian, Olli Haaskivi, Jason Clarke, James D'Arcy, Michael Angarano, Guy Burnet, Danny Deferrari, Matthias Schweighofer, Gary Oldman, Harrison Gilbertson, Emma Dumont, Devon Bostick, Olivia Thirlby, Trond Fausa, Christopher Denham and Josh Zuckerman. The film is set to release on July 21, 2023. /IANS