Daily Image

Click here or on the picture for a full size image.

De Inrichting van de Hemel

Submitter: Michel Arts
Description: Last year former chair of the ASTRON-board and former director of the Kapteyn Institute Piet van der Kruit published a biography of Jacobus Kapteyn. The title of the biography De Inrichting van de Hemel (The Construction of the Heavens) refers to William Herschel. He used this expression to mention the problem of spatial distribution of stars. Indeed a subject Kapteyn worked on.

The biography describes the whole career of Kapteyn. He studied mathematics and physics at the University of Utrecht where he got his Ph.D in 1875. After working a few years as observer at the Leiden observatory he was appointed as professor in Groningen in 1878 (at the age of 26). This appointment was a direct result of the new higher education act which resulted in an increase of the number of professors at Dutch universities. Around the same time Kapteyn's brother Willem was appointed as professor in mathematics at the University of Utrecht.

Contrary to the universities of Utrecht and Leiden, there was no observatory at the University of Groningen. After failed attempts to get an observatory in Groningen he started a co-operation with the observatory of Cape Town. This observatory was performing a survey to measure the positions and magnitudes of stars: the Cape Photographic Durchmusterung. The observatory didn't have enough manpower to process the photographic panels that resulted from this survey. Kapteyn didn't have an observatory, so a solution was found.

Using the proper motion of stars Kapteyn investigated the spatial distribution of stars. This investigation resulted in a model of the universe we nowadays know as the Kapteyn universe. Already shortly after the publication of this model it turned out that it was incomplete. The problem of attenuation of light due to dust in the universe was known by Kapteyn but the effect was underestimated.

This biography is a must-read for everyone who is interested in the history of (Dutch) astronomy. It is written in Dutch, however Piet van der Kruit has also written a more extensive scientific biography in English. Together with the book of David Baneke and the Ph.D thesis of Astrid Elbers this is the third book about the history of Dutch (radio) astronomy published the last two years.
Copyright: P.C. van der Kruit / Amsterdam University Press
  Follow us on Twitter
Please feel free to submit an image using the Submit page.