Franz Ernst Neumann (physicist)

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Franz Ernst Neumann, portrayed by Carl Steffeck , 1886

Franz Ernst Neumann (born September 11, 1798 in Mellin ; † May 23, 1895 in Königsberg ) was a German physicist and is considered one of the founders of theoretical physics . His students formed the "Königsberger Schule" and occupied almost all German chairs for physics.


Childhood and youth

Franz Ernst Neumann was the son of the divorced Countess Charlotte Friderike Wilhelmine von Mellin , b. von Kahlden (1753–1830), and their land manager Franz Ernst Neumann. His paternal ancestors worked in agriculture, his maternal ancestors were among others high officers in the Prussian army . His maternal grandfather was Frederick II's wing adjutant , a great-grandfather of the Hereditary Marshal of the Principality of Minden . Franz Neumann was mainly raised by his father and his paternal grandparents. Only in his youth did he find out about his mother and thus his noble descent. Despite his mother's fortune, he grew up in simple circumstances.

He developed a fighting spirit and patriotism at an early age , so that he fought as a war volunteer at the age of only 15 in the Colberg Grenadier Regiment during the wars of freedom against Napoleon . At the Battle of Ligny in 1815, he was hit by a bullet that tore apart parts of his face. As a result, he almost lost his life and had to learn to speak again.

Neumann made in Friedrichswerder school in Berlin his 1817 high school . Even then he acquired a great deal of mathematical knowledge, mostly outside of school lessons.


Although he had early expressed a desire mathematics to study, he started in accordance with the wishes of his father first, a study of theology in Berlin, then studied in Jena science and math and came in 1819 back to Berlin. His studies were financed by a scholarship from the Ministry of Education and the geologist Leopold von Buch . During his studies he became a member of the original fraternity .

Neumann studied and wrote his dissertation with the mineralogist Christian Samuel Weiss on the zone law in the crystal system . He gave a series of lectures on mineralogy in Berlin and took care of the Berlin Mineral Cabinet.

During his studies and his first academic work in Berlin, he was very interested in the work of French mathematicians such as Adrien-Marie Legendre and Jean Baptiste Joseph Fourier .

Academic career

Known for his work in Berlin, he went to the University of Königsberg in 1826 , where he completed his habilitation . There he made friends with the astronomer Friedrich Wilhelm Bessel and the natural scientist Karl Gottfried Hagen . After Hagen's death in 1829, Neumann was appointed full professor of mineralogy and physics . In the mid-1840s he was elected rector of the university. He gave up teaching in 1877; but worked as an emeritus at the University of Königsberg .

He was buried in the so-called scholarly cemetery at the observatory . A bronze plaque by Friedrich Reusch in the portico of the Albertina has honored him since 1898 .


In 1830 Neumann married Hagen's daughter Florentine (1800–1838), who died just eight years later and left him with five children: Carl Gottfried Neumann (1832–1925) was a professor of mathematics, Franz Ernst Christian Neumann (1834–1918) was a professor of pathology and hematology, Friedrich Julius Neumann (1835–1910) was a professor of economics. The daughter Luise Neumann (1837–1934) wrote his life story “Franz Ernst Neumann, Memories Sheets” . She donated his estate to the City History Museum in Königsberg , which furnished a Neumann room.

After the death of his first wife, he married her cousin Wilhelma Hagen, who died in 1877.

Scientific work

Franz Ernst Neumann's research extended to problems in crystallography , specific heat , the wave theory of light , induction currents and mathematical methods in physics . For his scientific merits he was accepted on August 17, 1860 in the Prussian order Pour le mérite for science and the arts .

Crystallography and mineralogy

His most important studies on the properties of crystals and minerals , which he wrote between 1830 and 1834, concerned specific heat. He developed a more precise version of the method of mixtures and extended the Dulong-Petit law from simple to compound substances. The discovery that the specific heat of water increases with temperature also dates back to this time. The Neumann principle links the properties of a crystal with the structure of the crystal. The discovery of Neumann lines in meteorites is often attributed to him, but these were discovered by Johann G. Neumann.

Wave theory of light

In the 1830s he continued to study various aspects of the wave theory of light . The question of whether light has a wave nature (as Christian Huygens was the first to explain) or whether it is composed of corpuscles (as Sir Isaac Newton believed), at that time seemed to have been decided in favor of the wave theory, although one assumed a subtle ether in which the waves move. In 1832, Neumann developed a theory of birefringence , for which he understood the ether as an elastic medium that could be treated according to Claude Navier's equations of elasticity. Neumann's theory presupposed longitudinal waves in addition to the transverse waves already assumed .


In the mid-1840s, Neumann did research in the field of electromagnetism . In 1845 he published a general theory of induction currents for closed circuits. Two years later he generalized his theory to altered intensities of the current. Neumann's work formed a basis for German research in this area until it was gradually superseded by Maxwell's theories.


1844 Dr. med. honoris causa (Medical Faculty Königsberg);

1844 Red Eagle Order II class (1886 with star); 1860 Order Pour le Mérite for Science and the Arts ; 1872 Bavarian Maximilian Order for Science and Art ; 1877 Copley Medal from the Royal Society ; 1888 Order of the Crown, 1st class with star; 1894 Real Privy Councilor and Excellency; 1835 corresponding member of the Academy of Sciences in Berlin, from 1838 member of the Petersburg Academy of Sciences , from 1856 external member of the Göttingen Academy of Sciences , from 1862 external member of the Royal Society and other European academies.

1886 oil painting by Carl Steffeck for the Royal National Gallery in Berlin (on behalf of the king for bearers of the order Pour le Mérite)

Neumann Peak on Hansen Island in Antarctica has been named after him since 1965 .


Neumann's publications were mainly edited by his students.

  • Franz Ernst Neumann: De lege zonarum principio evolutionis systematum crystallinorum. Berlin 1826.
  • Karl Gottfried Neumann (ed.): Lectures on the theory of magnetism. Leipzig 1881.
  • Carl Pape (ed.): Introduction to theoretical physics. Leipzig 1883.
  • von der Mühll (Ed.): Lectures on electrical currents. Leipzig 1884.
  • Dorn (ed.): Lectures on theoretical optics. Leipzig 1885.
  • OE Meyer (Ed.): Lectures on the theory of elasticity. Leipzig 1885.
  • Karl Gustav Neumann (Ed.): Lectures on the theory of potential. Leipzig 1887.
  • Wangerin (Ed.): Lectures on Capillarity. Leipzig 1894.


  • Robert Knott:  Neumann, Franz Ernst . In: Allgemeine Deutsche Biographie (ADB). Volume 52, Duncker & Humblot, Leipzig 1906, pp. 680-684.
  • Florian Hars:  Neumann, Franz Ernst. In: New German Biography (NDB). Volume 19, Duncker & Humblot, Berlin 1999, ISBN 3-428-00200-8 , p. 132 f. ( Digitized version ).
  • Rudolf Fritsch , E. Neumann-Redlin von Meding, T. Schenk (eds.): Franz Ernst Neumann (1798–1895) - For the 200th birthday of the mathematician, physicist and crystal graph . Publishing house "Terra Baltica" / Ludwig Maximilians University Munich, Kaliningrad / Munich 2005, ISBN 3-922480-17-9 .
  • E. Neumann-Redlin von Meding: Franz E. Neumann (1798–1895) Role Model as Man and Scientist - On the 200th birthday of the Königsberg physicist and mineralogist. In: Königsberger Bürgerbrief. No. 51, 1998, pp. 40-45.
  • E. Neumann-Redlin von Meding: The scholars on the "old Neurossgärter cemetery", the scholarly cemetery in Königsberg. In: Königsberger Bürgerbrief. No. 80, 2012, pp. 54-56.
  • Kathryn M. Olesko: Physics as a calling . Cornell University, Ithaca / London 1991.
  • Kathryn M. Olesko: The physicist as a teacher. On the hundredth anniversary of the death of Franz Ernst Neumann (1798–1895). In: Physical sheets. Volume 51, 1995, pp. 522-524. (on-line)
  • Peter Paufler , E. Neumann-Redlin from Meding: Franz E. Neumann. For the 200th birthday of the Königsberg mineralogist and physicist. In: Reports of the German Mineralogical Society Beih. Z. Eur.J. Mineral. Vol. 10, No. 1, 1998, pp. 13-21.
  • Andreas Trunschke : The Königsberg physicist F. Neumann and the Prussian Academy of Sciences. In: NTM series of publications for the history of the natural sciences, technology and medicine. 27, 2, Leipzig 1990, pp. 1-11.
  • Albert Wangerin : Franz Neumann and his work as a researcher and teacher. Vieweg, Braunschweig 1907.

Web links

Commons : Franz Ernst Neumann  - Collection of images, videos and audio files
Wikisource: Franz Ernst Neumann  - Sources and full texts

Individual evidence

  1. Mellin - the birthplace of a great Brandenburg citizen on
  2. a b c Robert Albinus: Königsberg Lexicon . Würzburg 2002, ISBN 3-88189-441-1 .
  3. ^ Peter Kaupp (edit.): Stamm-Buch of the Jenaische Burschenschaft. The members of the original fraternity 1815-1819 (= treatises on student and higher education. Volume 14). SH-Verlag, Cologne 2005, ISBN 3-89498-156-3 , p. 140.
  4. ^ Johann G. Neumann: About the crystalline structure of the meteoric iron from Braunau. In: Naturwissenschaftliche Abhandlungen Wien. 3, 1849, pp. 45-56.
  5. Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 178.