J. Robert Oppenheimer

Character: Self (archive footage)

Ellen Bradbury Reid

Character: Self - Daughter of Los Alamos Scientist

Christopher Nolan

Character: Self - Writer / Director, "Oppenheimer"

Jon Else

Character: Self - Filmmaker, "The Day After Trinity"

Kai Bird

Character: Self - Co-Author, "American Prometheus"

Bill Nye

Character: Self - Science Educator

Richard Rhodes

Character: Self - Author, "The Making of the Atomic Bomb"

Mareena Robinson Snowden

Character: Self - Nuclear Security Expert

Alan B. Carr

Character: Self - Senior Historian, Los Alamos National Laboratory

Gregg Herken

Character: Self - Author, "Brotherhood of the Bomb"

Jennet Conant

Character: Self - Author, "109 East Palace"

David Eisenbach

Character: Self - History Professor, Columbia University

Alex Wellerstein

Character: Self - Nuclear Historian

Martin J. Sherwin

Character: Self - Co-Author, "American Prometheus" (voice)

Michio Kaku

Character: Self - Theoretical Physicist

Leslie Groves

Character: Self - Director, Manhattan Project (voice) (archive sound)

Charles Oppenheimer

Character: Self - Grandson

Robert Christy

Character: Self - Theoretical Physicist (voice) (archive sound)

Robert S. Norris

Character: Self - Author, "Racing for the Bomb"

Hideko Tamura

Character: Self - Hiroshima Survivor (Age 10)

Roy Glauber

Character: Self - Scientist, Manhattan Project (voice) (archive sound)

Edward Teller

Character: Self - Theoretical Physicist (archive footage)

Eleanor Roosevelt

Character: Self (archive footage)

Judy Woodruff

Character: Self (voice) (archive sound)

Adolf Hitler

Character: Self (archive footage)

Vladimir Putin

Character: Self (archive footage)

Xi Jinping

Character: Self (archive footage)

Albert Einstein

Character: Self (archive footage)