The Collected Papers of Frits Zernike (1888-1966) are planned to reproduce in two stages the scientific work of Groningen's distinguished 1953 Nobel laureate for Physics. The first stage comprises the original texts, mostly in French, German, and Dutch, published in two volumes, I and II. The second stage concerns an exclusively English rendition of those papers, also in two volumes (III and IV), and, besides, a fifth volume with an apparatus criticus consisting of an introduction and clarifying notes to each individual article, bibliographies of primary and secondary sources, and indexes (subjects, names).

The first volume reproduces Zernike's papers from the period 1911-1932, that is, from his prize-winning essay on the mathematical foundation of the clock and hammer game up to and including an analysis of the Brownian limit of a series of observations. The frontispice is decorated with a photograph of a painting (oil on canvas; 60x50 cm), newly made for the purpose by Eric Bos (Groningen; www.visualia.nl). There are i.a. some 13 papers co-authored with Leonard Ornstein (1880-1941), Zernike's life-long friend whom he succeeded in 1915 as associate professor of theoretical physics at the University of Groningen. There are, moreover, his doctoral dissertation (1915) on critical opalescence and its theoretical and experimental implications, and an in-depth study of probability theory and mathematical statistics, composed for the mathematical part of the Handbuch für Physik (1928).
The second volume reproduces Zernike's papers from the period 1933-1958. It opens with the abstract of a paper in which he announced the discovery of the phase contrast method, in 1933, at the annual Congress of the Dutch Natural and Medical Scientists, which was followed by an almost exhaustive paper in the Monthly Notices of the Royal Astronomical Society (1934). There are also his papers on the diffraction theory of aberrations, featuring the famous circle polynomials (1934-). This volume closes with Zernike's farewell speech on becoming emeritus, on 16 July 1958.
Volumes III and IV feature English translations of all papers.