Albert Einstein
Mileva Maric
Michael Faraday
Brande
Chater
Humphry Davy (as Sam West)
Newman
Hermann Einstein
Professeur Fritz Muhlberg (as Mike Sarne)
Marie Anne Lavoisier
Antoine Lavoisier
Count de Amerval
Baroness de la Garde
Marat
Manson
Besso
Maxwell
Emilie du Châtelet
Charles de Breteuil
Emilie's Tutor
Emilie's Father
Voltaire
Algarotti
Maupertuis
Dr. Haller
Habicht (as Andrew Crabb)
Lise Meitner
Otto Hahn (as Christian Pedersen)
Strassman (as Michael Mueller)
Horlein
Robert Frisch
Narrator (voice)
Speaker (uncredited)