Kapteyn and de Sitter; A Rare and Special Teacher-Student and Coach-Player Relationship

Abstract

Measured along the yardstick of subsequent success, Willem de Sitter [1872–1934] was one of Kapteyn’s foremost pupils along with van Rhijn, Schilt and Jan Hendrik Oort. From his appointment as professor at Leiden University in 1908 until Kapteyn’s death in 1922, de Sitter maintained in close contact with his teacher. Kapteyn was his trusted sounding board and consultant in scientific and administrative matters, as well as academic politics. De Sitter had his ideas on a complete reorganisation and restructuring of Leiden Observatory scrutinized by Kapteyn’s experienced judgement, and together they developed ideas and completed a plan of action, including touchy staffing, salary and budgetary aspects. Together they were a formidable team and operated as such. Notes by de Sitter and many letters from Kapteyn illustrate their fruitful relationship.

Prof. ir. Wolter Reinold de Sitter (October 17, 1936) graduated cum laude in civil engineering in 1961 at Delft University of Technology. Between 1970 and 1997 he was employed by H.B.G. n.v. (general international contractors), from 1980 as director of Technology Development. In 1986 he was appointed parttime professor in design of structures in concrete at Eindhoven University of Technology. In 1997, at the occasion of his retirement from H.B.G., de Sitter was awarded the order of Officier in de Orde van Oranje-Nassau. In 1997 de Sitter started a review of documents pertaining to his grandfather, the astronomer Willem de Sitter, in the archives of the Observatory at Leiden University.