Theodor Spieker

Theodor Spieker (8 August 1823 – 9 April 1913) was a German mathematician, a teacher at a gymnasium in Potsdam.[1]

Spieker's geometry textbook Lehrbuch der ebenen Geometrie mit Übungs-Aufgaben für höhere Lehranstalten (Verlag von August Stein, Potsdam, 1862)[2][3] was republished in many editions. A copy of this textbook was given to Albert Einstein by his tutor when Einstein was twelve, and quickly led Einstein to become interested in higher mathematics.[4]

Spieker is the namesake of the Spieker circle of a triangle (the circle inscribed in its medial triangle) and the Spieker center (the center of the Spieker circle).

  1. ^ Embacher, Franz (2008), "Die Schwerpunkte des Dreiecks" (PDF), Mathematische Semesterberichte, 55 (2): 131–148, doi:10.1007/s00591-008-0040-8, S2CID 122490596.
  2. ^ Worldcat entry for Lehrbuch der ebenen Geometrie, accessed 2012-05-05.
  3. ^ Lehrbuch der ebenen Geometrie mit Übungs-Aufgaben für höhere Lehranstalten (1898 ed.) on Google Books, accessed 2012-05-05.
  4. ^ Clark, Ronald W. (1984), Einstein: The Life and Times, HarperCollins, p. 34, ISBN 9780380011599.