December 1919
30 November - 6 December
At its party convention in Leipzig, the USPD adopts an action program in which it aims to bring an end to class domination and to establish a council system. This radically ideological orientation makes cooperation with the SPD, let alone a reunification of the two parties, in the foreseeable future impossible. However, with its 750,000 members, the USPD remains a strong, firmly established party. The KPD on the other hand has not progressed beyond its status as a splinter party as of the end of 1919. [Kolb, p. 38]
10 December
Max Planck (physics) and Fritz Haber (chemistry) receive the Nobel Prize retrospectively for the year 1918. Johannes Stark receives the Nobel Prize in Physics for the year 1919. [Büttner, p. 775]
22 December
The Königs Wusterhausen long-wave radio station of the Reichspost (postal authorities) broadcasts a concerto for the first time. [Büttner, p. 777]