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)