Als bij toverslag”. De reorganisatie en nieuwe bloei van de Leidse Sterrewacht, 1918-1924

Abstract

In 1918, Leyden Observatory was a somewhat backward institute, but by 1928 it had transformed itself into a prominent international scientific centre. This article describes the reorganisation and expansion of the Observatory between 1918 and 1924 under the leadership of W. de Sitter, starting with the appointment of De Sitter and E. Hertzprung and the rejection, for political reasons, of A. Pannekoek. It also presents a reconstruction of the reorganisation. The article also describes the changes in Dutch astronomy in the 1920s: its expansion, the establishment of national organisations, and the extension of international contacts, especially with Anglo Saxon countries. Leyden became a centre in the international astronomer’s network, partly thanks to the influence of the Groningen astronomer J.C. Kapteyn. After the First World War, it played an important role as the link between scientists from the former Allied and Central countries. The thorough theoretical and practical training given at Leyden Observatory produced young astronomers that were highly valued all over the world. Combined with the international contacts and diplomatic skills of De Sitter, this formed the foundation from which the Observatory went on the prosper. One curious aspect is that the Observatory’s scientific findings played a minor role in this success.