Marcel Gilles Jozef Minnaert (Bruges1893 - February 12, Utrecht26 October 1970) was a biologistborn in Belgium , astrophysicistart educatorflamingantesperantist,pacifist and marxist. He is best known as a pioneer of the spectroscopic examination of the Sun and as a gifted art educator.


[hide]*1 years of study

Years Of Study[Edit]Edit

Mae was born in a Liberal, Liberal, Flemish family. His father was a teacher. He attended primary school in Bruges, and when his father died, he moved with his mother to Ghent. He followed secondary education at the Atheneum of Ghent studied there in 1910. Among his teachers were Hippolyte Meert, René De Clercq, Jan Oskar De Gruyter, August Borms, all teachers that are bountifully supplied Vlaamsgezindheid. He was a member of The Heremanszonen and it will go though .

From 1910 to 1914 studied Mae biology, including Julius Mac Leod. In 1914 he graduated summa cum laude with a thesis on quantitative photo biology (research on the effect of light on plants).

During his college studies radicalized Mae and was an anti-Belgian flamingant. He was co-organizer of the greater Dutch studentencongresse, along with Reverend Pieter Geyl and Jan Derk Domela Nieuwenhuis Nyegaard.

In July 1914 he travelled with his mother in Norway weather in Ghent, and when he came, it was war. He refused military service, but helped to organize a training college in the Ghent hospital.

First World War[Edit]Edit

On October 12, 1914 fled Mae to Sluis and pulled from there to Lead, then the Mecca of physics. He got good contacts with Jan Romein, Lorentz, Kammerling-Onnes and with the couple Ehrenfest.

In 1916, the Dutch-speaking University of Ghent which the reputation gets an initiative of the occupier to be (with calls them ' the Von Bissinguniversiteit, the German commander out there at the base of lies). Mae endeavors to find teachers for this University, which is not conducted by the above quoted Leidse of colluding with the enemy this scientists, who as judge.

When the University was opened in 1916, was Mae lecturer physics and remained so until at the end of the war. In 1918, his home looted and he fled with his mother to Zeist. He was convict in absentia to 15 years hard labor. In the meantime he joined the solar physicist William Julius in Utrecht.

In Netherlands[Edit]Edit

Madhusudan was soon an Assistant to William Julius for his examination of the Sun. In 1925, he was promoted again (second promotion) with professor l. s. Ornstein, the successor to Julius, with a dissertation onIrregular RADIUS curvature. In 1928 he married Miep Camargo. He was by then evolved considerably and he was far left of right-wing fascist marxist and soon become communist. On the funeral of René De Clerckhe was present and while some of his former friends under the singing of the Flemish lion brought the fascist greeting, he saluted with a clenched linkervuist.

In 1937 he assigned an appointment at the University of Chicago and he was appointed Professor and Director of the Utrecht Observatory.

Second World War[Edit]Edit

From May 1942 to 20 april 1944 was Mae interned in the internment camp Sint-Michielsgestel. several of the 600 inmates were executed. Mae taught his fellow hostage in the physics and astronomy.

In april 1944 he was released (Hitler's birthday). After his return to learn Mae that two students were hiding in ' his ' Observatory, which was a big shock to him. How radical and links Mae had become, he was also law-abiding. [1this was not the only contradiction in his character. So had the great art educator Mae the habit complain exams by students at most futile details. [2]

In 1946 was Madhusudan was appointed member of the Royal Netherlands Academy of Arts and Sciences (KNAW). By its political preference he could no be rector of Utrecht University during the cold war. In 1951 he became a member of the Royal Flemish Academy.

His broad interest went out to many areas outside astronomy. He was more esperantist. He was a talented musician and a Wagner fanatic.



Minnaert did pioneering work in the field of spectroscopy and spectral lines, where he among other things was the method of the growth curve (curve of growth) and the equivalent width.


View Minnaerts broad interest and comment brought him all kinds of everyday phenomena on a clear way for a wider audience to investigate in his physics of the open field, that was translated in many languages and got international following. A book with practical experiments for astronomy.


  • many scientific articles
  • Contributions à la Photobiologie quantitative dissertation , Gent1914
  • The Division of labor and the Nationality principle, in Dietsche Votes 1 (1916) II, 298-317; 452-474
  • Irregular Radius Curvature. Thesis Utrecht, 1925
  • The Physics of the Sun, the Hague, 1936
  • The Physics of 't open field, 3 parts, 1937-1942, and many later reprints, Thieme, Zutphen
  • with guest, Mulders, j. Wood G.F.W. Photometric Atlas of the Solar Spectrum, Amsterdam, 1940
  • Poets about stars, Arnhem, 1949
  • The Photosphere and Photometry of the Moon, in G.P. Kuiper, The solar system, Chicago, 1953-) dl. I, 88-185 and dl. III, 213-248
  • Forty Years of Solar Spectroscopy, in c. DanielThe solar spectrum, Dordrecht, 1965, 3-25.
  • Practical Work in Elementary Astronomy, Reidel, Dordrecht, 1969 (prakticumproeven)

Of the work of Mae enjoy physics van 't free field spacious fame.


[1][2]Minnaert building in Utrecht.*On De Uithof, Utrecht University's campus, is a building called to Minnaert. The Department is In this Nature-and Minnaert building astronomy of the Faculty of science housed.

  • In the district to sterrenburg Dordrecht there is a street named to Minnaert. The Minnaertweg is the main road for several adjacent streets (rings).
  • Scientific recognitions:
  • The Minnaert correction (or Minnaert albedo)
  • The lunar crater Minnaert
  • The asteroid # 1670 Minnaert


  • Lynch, David & Livingston, William: Light and color in nature, Cambridge University Press, 1995, translated as light and colour in nature, Veen Magazines, Diemen, 2006


In the attack by Harry Mulisch is The Physics of 't open field called:

"They did it really, there was nothing more to do! The house burned inside and out. All his stuff, his books, Karl May, its physique of the free field, his collection of aircraft photographs, the library of his father, with the strips green sheet against the boards, his mother's clothes, the knot wool, the chairs and tables: all went up. The soldier screwed his flamethrower close and disappeared into the dark.(page 41) "