Friedrich Haag (crystallographer)

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Friedrich Haag (born August 20, 1856 in Schwenningen am Neckar , † December 8, 1941 in Stuttgart - Degerloch ) was a German pioneer of crystallography .

life and work

Haag studied in Stuttgart and Tübingen from 1874 to 1881 . He received his doctorate as Dr. rer nat. and became an assistant teacher in Reutlingen in 1877 . In 1881 he became a teacher at the secondary school in Rottweil , where he became a professor in 1882. From 1899 he was professor and from 1900 rector at the Real Institute in Tübingen. In 1903 he became professor at the Wilhelm Realschule in Stuttgart and in 1908 until his retirement in 1927 he was professor and rector at the Friedrich-Eugen-Realschule in Stuttgart. He was a teacher.

He is still known today for his publications on crystallography. In 1887 he published a generalization of Leonhard Sohncke's definition of crystal lattices as regular point systems that could not explain some naturally occurring crystal structures. Haag proposed the assumption of several such point systems in the crystal. The work, published somewhat remotely, was made known to wider circles by Ernst Karl Friedrich Blasius and taken over by Sohncke.

In a work from 1929 he derived the district camps from Paul Niggli .

An article by Haag in the Zeitschrift für Kristallographie also served as an important source for MC Escher for his graphics of tiling.

But he was also a collector and published essays on crystallography on geology and paleontology.

In 1928 he became an honorary member of the Association for Patriotic Natural History in Württemberg. He is the father of Friedrich Erhard Haag .

More fonts

Unless cited yet:

  • Organic residues from Rottweiler's Letten coal. In: Annuals of the Association for Patriotic Natural History in Württemberg, 48, Plate VII, Stuttgart 1892, pp. 234–237
  • Grid vectors , supplement to the program of the Royal Wilhelm Realschule in Stuttgart 1907
  • The polygons corresponding to the multiples of the regular crystal systems , Z. f. Kristallogr., Volume 42, 1907
  • Content and surface of the regular crystal bodies , Z. f. Kristallogr., Volume 52, 1912/13
  • The regular plan divisions (PDF file; 2.41 MB), line f. Kristallogr., Vol. 49, 1911, 360-369
  • Lattice planes in regular crystals , Z. f. Kristallogr., Volume 55, 1920
  • Lattice planes and family of lines , Z. f. Kristallogr., Volume 56, 1921
  • The regular plan division and point systems (PDF file; 2.74 MB), Z. f. Kristallogr., Vol. 58, 1923, 478-489
  • 17 regular plan divisions and point systems , Z. f. Kristallogr., Volume 61, 1924/25, p. 58
  • The pentagonal arrangement of touching circles in the plane (PDF file; 985 kB), line f. Kristallogr., Vol. 61, 1925, 339-340
  • Fedorow's Planigone (PDF file; 1.87 MB), line f. Kristallogr., Vol. 63, 1926, 179-186
  • The symmetry relationships of a regular plan division (PDF file; 1.29 MB), Journal for Mathematical and Natural Science Education, Volume 57 (1926), 262–263
  • Geometry of the lattice planes , Z. f. Kristallogr., Volume 70, 1929
  • Territory and scope , Z. f. Kristallogr., Volume 78, 1931, p. 167
  • Structural formulas for plane divisions , Z. f. Kristallogr., Vol. 83, 1932, pp. 31-37
  • Basic equations for plane and space division , Z. f. Kristallogr., Volume 86, 1933, p. 153
  • The polygons assigned to the numbers 1-100 in the cubic lattice , Z. f. Kristallogr., Vol. 90, 1935, pp. 456-466
  • Polygons of the plane division , Z. f. Kristallogr., Vol. 96, 1937, pp. 77-80
  • Space grid numbers , Z. f. Kristallogr., Volume 97, 1937, p. 234

Web links

References and comments

  1. ↑ Biographical data from the annual journal of the Society for Natural History in Württemberg, Volume 130-132, 1975 and Poggendorff's Literarisch-Biographisches Concise Dictionary for the History of Exact Sciences , editions 1904, 1937 and 1958
  2. ^ Sohncke The regular plane point systems of unlimited extension , Journal für Reine und Angewandte Mathematik, Volume 77, 1874, pp. 41-101, The unlimited regular point systems as the basis of a theory of the crystal structure , Karlsruhe 1876. Development of a theory of crystal structure , Leipzig 1879
  3. ↑ Haag The regular crystal bodies , program of the Royal High School in Rottweil at the end of the school year 1886/87 (40 pages)
  4. ^ Blasius, review of Haags essay, Zeitschrift für Kristallographie und Mineralogie, Volume 14, 1888, pp. 501–502
  5. ^ Sohncke expansion of the theory of crystal structure , Zeitschrift für Kristallographie, Volume 14, 1888, pp. 426–446
  6. ^ Haag Die Kreislagerungen von Niggli , Zeitschrift für Kristallographie, Volume 70, 1929, pp. 353–366
  7. ^ Haag The regular plan divisions and point systems , Zeitschrift für Kristallographie, Volume 58, 1923, pp. 478–489  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF file; 2.74 MB). Otherwise Escher only found an essay by George Pólya useful.@1@ 2Template: Dead Link / www2.dm.unito.it  
  8. ↑ Doris Schattschneider The Mathematical Side of MC Escher , Notices AMS, June / July 2010, p.707 (PDF file; 6.38 MB)
  9. ↑ Annual Books Society f. Natural history Württemberg. Among other things, on the geology of Rottweil and the surrounding area , grammar school program Rottweil 1897, Diluvium in Rottweil , annual report Württemb. Verein Naturf., Volume 58, 1902. On the geology of the area around Rottweil , Blätter des Schwäbischer Albverein , Volume 25, 1913, pp. 78–79
  10. ^ Honorary members of the Association for Patriotic Natural History in Württemberg
  11. ↑ Poggendorff Lit-Biogr. Hand dictionary.
personal data
SURNAME Haag, Friedrich
BRIEF DESCRIPTION German crystallographer
DATE OF BIRTH August 20, 1856
PLACE OF BIRTH Schwenningen am Neckar
DATE OF DEATH December 8, 1941
Place of death Stuttgart