J. Robert Oppenheimer

Self (archive footage)

Ellen Bradbury Reid

Self - Daughter of Los Alamos Scientist

Christopher Nolan

Self - Writer / Director, "Oppenheimer"

Jon Else

Self - Filmmaker, "The Day After Trinity"

Kai Bird

Self - Co-Author, "American Prometheus"

Bill Nye

Self - Science Educator

Richard Rhodes

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

Mareena Robinson Snowden

Self - Nuclear Security Expert

Alan B. Carr

Self - Senior Historian, Los Alamos National Laboratory

Gregg Herken

Self - Author, "Brotherhood of the Bomb"

Jennet Conant

Self - Author, "109 East Palace"

David Eisenbach

Self - History Professor, Columbia University

Alex Wellerstein

Self - Nuclear Historian

Martin J. Sherwin

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

Michio Kaku

Self - Theoretical Physicist

Leslie Groves

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

Charles Oppenheimer

Self - Grandson

Robert Christy

Self - Theoretical Physicist (voice) (archive sound)

Robert S. Norris

Self - Author, "Racing for the Bomb"

Hideko Tamura

Self - Hiroshima Survivor (Age 10)

Roy Glauber

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

Edward Teller

Self - Theoretical Physicist (archive footage)

Eleanor Roosevelt

Self (archive footage)

Judy Woodruff

Self (voice) (archive sound)

Adolf Hitler

Self (archive footage)

Vladimir Putin

Self (archive footage)

Xi Jinping

Self (archive footage)

Albert Einstein

Self (archive footage)