J. Robert Oppenheimer as Self (archive footage)

Ellen Bradbury Reid as Self - Daughter of Los Alamos Scientist

Christopher Nolan as Self - Writer / Director, "Oppenheimer"

Jon Else as Self - Filmmaker, "The Day After Trinity"

Kai Bird as Self - Co-Author, "American Prometheus"

Bill Nye as Self - Science Educator

Richard Rhodes as Self - Author, "The Making of the Atomic Bomb"

Mareena Robinson Snowden as Self - Nuclear Security Expert

Alan B. Carr as Self - Senior Historian, Los Alamos National Laboratory

Gregg Herken as Self - Author, "Brotherhood of the Bomb"

Jennet Conant as Self - Author, "109 East Palace"

David Eisenbach as Self - History Professor, Columbia University

Alex Wellerstein as Self - Nuclear Historian

Martin J. Sherwin as Self - Co-Author, "American Prometheus" (voice)

Michio Kaku as Self - Theoretical Physicist

Leslie Groves as Self - Director, Manhattan Project (voice) (archive sound)

Charles Oppenheimer as Self - Grandson

Robert Christy as Self - Theoretical Physicist (voice) (archive sound)

Robert S. Norris as Self - Author, "Racing for the Bomb"

Hideko Tamura as Self - Hiroshima Survivor (Age 10)

Roy Glauber as Self - Scientist, Manhattan Project (voice) (archive sound)

Edward Teller as Self - Theoretical Physicist (archive footage)

Eleanor Roosevelt as Self (archive footage)

Judy Woodruff as Self (voice) (archive sound)

Adolf Hitler as Self (archive footage)

Vladimir Putin as Self (archive footage)

Xi Jinping as Self (archive footage)

Albert Einstein as Self (archive footage)