Biographical movie about Julius Robert Mayer (1814-1878), a surgeon and town doctor in Heilbronn, who studied heat for many years and was the first to correctly formulate the basic principles of the theory of mechanical heat and the principle of conservation of energy. Competing Prussian scientists laugh at him, and his life is full of misunderstandings and persecution. The film tells of his fate and his long and futile struggle for recognition of the results of his scientific work.

Emil Stöhr
as Robert Mayer

Gisela Uhlen
as Wilhelmine Mayer

Hilmar Thate
as Dr. Bohn

Otto Stübler
as Closs

Martin Flörchinger
as Fritz Mayer

Walther Suessenguth
as Privy Councilor Justus Liebig

Herwart Grosse
as Court Councilor Ernst von Zeller

Harald Halgardt
as Dr. Landerer

Gerd Michael Henneberg
as Prof. Gustav Rümelin

Werner Segtrop
as Von Rauch