Marcel Minnaert

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Marcel Minnaert
Minnaert in 1967
Marcel Gilles Jozef Minnaert

(1893-02-12)12 February 1893
Bruges, Belgium
Died10 October 1970(1970-10-10) (aged 77)
Utrecht, Netherlands
Alma materGhent University
Utrecht University
Known forMinnaert resonance
Minnaert function
AwardsPrix Jules Janssen (1966)
Bruce Medal (1951)
Gold Medal of RAS (1947)
Scientific career
InstitutionsUtrecht University
Doctoral advisorLeonard Ornstein
Doctoral studentsHendrik C. van de Hulst[1]
Kees de Jager

Marcel Gilles Jozef Minnaert (12 February 1893 – 26 October 1970) was a Belgian-Dutch astronomer.[2] He was born in Bruges and died in Utrecht. He is notable for his contributions to astronomy and physics and for a popular book on meteorological optics: Light and colour in the open air, first published in English in 1940.


Minnaert obtained a PhD in biology at Ghent University in 1914. Later he obtained also a PhD in physics from Utrecht University, under the supervision of Leonard Ornstein.

He was a supporter of the Flemish movement during World War I and endorsed the replacement of French by Dutch during the German occupation of Belgium. He worked as "lector fysica" at the new Flemish University of Ghent, which was made possible by the support of the German occupation forces, and was viewed as connivance with the enemy by the reestablished Belgian authorities. Because of this, he was sentenced after the war in absence to 15 years of forced labor. However, Minnaert had anticipated this outcome by fleeing Belgium in time.

In 1918, he found a position at Utrecht University in the Netherlands, initially to do photometric research. In Utrecht, he became interested in astronomy, and he became a pioneer of solar research. He specialized in spectroscopy and the study of stellar atmospheres and invented the spectroscopic curve of growth.

Minnaert was also interested in bubbles and musical nature of the sounds made by running water. In 1933 he published a solution for the acoustic resonance frequency of a single bubble in water, the so-called Minnaert resonance.

In 1937, he was appointed director of the stellar observatory Sonnenborgh in Utrecht and full professor in astronomy at the university. In 1940, he published his famous Utrecht Atlas of the solar spectrum. In 1941, he invented the Minnaert function, which is used in optical measurements of celestial bodies.

During the German occupation of the Netherlands in World War II, he was imprisoned by the Germans because of his left-wing, anti-fascist sympathies. During his incarceration, he taught physics and astronomy to his fellow prisoners. After the War, he was one of the founders of the Mathematisch Centrum in Amsterdam.

Minnaert was elected to the American Academy of Arts and Sciences in 1959.[3] In 1946 he became member of the Royal Netherlands Academy of Arts and Sciences.[4] He became a member of the United States National Academy of Sciences in 1964 and the American Philosophical Society in 1969.[5][6]


  • Practical Work in Elementary Astronomy, D. Reidel, 1969,[7] ISBN 978-94-010-3416-6; 2012 pbk reprint

One of his interests was the effects of the atmosphere on light and images. His classic book on this subject, the first part of a trilogy, was originally published in Dutch in 1937 as:



Named after him


  1. ^ Habing, H. J. (February 2001). "Obituaries: Hendrik Christoffel van de Hulst, 1918-2000". Astronomy & Geophysics. 42 (1): 1.33–1.37. Bibcode:2001A&G....42a..33H. doi:10.1046/j.1468-4004.2001.0420011.33.x.
  2. ^ Minnaert, Marcel Gilles Jozef (1893-1970), Huygens Institute
  3. ^ "Marcel Gilles Jozef Minnaert". American Academy of Arts & Sciences. Retrieved 2022-09-13.
  4. ^ "Marcel Gilles Jozef Minnaert (1893 - 1970)". Royal Netherlands Academy of Arts and Sciences. Retrieved 30 July 2015.
  5. ^ "Marcel G. Minnaert". Retrieved 2022-09-13.
  6. ^ "APS Member History". Retrieved 2022-09-13.
  7. ^ Kolchinskii, I. G. (1973). "Book Review: Practical Work in Elementary Astronomy by M. G. J. Minnaert". Soviet Astronomy. 16 (4): 732–734. Bibcode:1973SvA....16..732K.
  • Molenaar, Leo. De rok van het universum: Marcel Minnaert, astrofysicus 1893–1970 Balans, Amsterdam, 2003 [in Dutch]. ISBN 90-5018-603-3

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