Friedrich Robert Helmert
||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (November 2009)|
Helmert was born in Freiberg, Kingdom of Saxony. After schooling in Freiberg and Dresden, he entered the Polytechnische Schule, now Technische Universität, in Dresden to study engineering science in 1859. Finding him especially enthusiastic about geodesy, one of his teachers, August Nagel, hired him while still a student to work on the triangulation of the Erzgebirge and the drafting of the trigonometric network for Saxony. In 1863 Helmert became Nagel's assistant on the Central European Arc Measurement. After a year's study of mathematics and astronomy Helmert obtained his doctor's degree from the University of Leipzig in 1867 for a thesis based on his work for Nagel.
In 1870 Helmert became instructor and in 1872 professor at RWTH Aachen, the new Technical University in Aachen. At Aachen he wrote Die mathematischen und physikalischen Theorieen der höheren Geodäsie (Part I was published in 1880 and Part II in 1884). This work laid the foundations of modern geodesy. See history of geodesy. Part I is devoted to the mathematical aspects of geodesy and contains a comprehensive summary of techniques for solving for geodesics on an ellipsoid.
The method of least squares had been introduced into geodesy by Gauss and Helmert wrote a fine book on least squares (1872, with a second edition in 1907) in this tradition, which became a standard text. In 1876 he discovered the chi-squared distribution as the distribution of the sample variance for a normal distribution. This discovery and other of his work was described in German textbooks, including his own, but was unknown in English, and hence later rediscovered by English statisticians – the chi-squared distribution by Karl Pearson (1900), and the application to the sample variance by 'Student' and Fisher.
Helmert received many honours. He was president of the global geodetic association of "Internationale Erdmessung", member of the Prussian Academy of Sciences in Berlin, was elected a member of the Royal Swedish Academy of Sciences in 1905, and recipient of some 25 German and foreign decorations.
- Helmert transformation (in geodesy)
- Helmert's equation
- coordinate system
- Helmert–Wolf blocking
- national survey
- terrestrial gravity field
- Geodesics on an ellipsoid
- Hald 1998, p. 633: "[It] is a pedagogical masterpiece; it became a standard text until it was superseded by expositions using matrix algebra."
- Hald 1998, pp. 633–692, 27. Sampling Distributions under Normality.
- F. R. Helmert, "Ueber die Wahrscheinlichkeit der Potenzsummen der Beobachtungsfehler und über einige damit im Zusam- menhange stehende Fragen", Zeitschrift für Mathematik und Physik 21, 1876, S. 102–219
- Helmert, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
- Walther Fischer "Helmert, Friedrich Robert" Dictionary of Scientific Biography volume 7, pp. 239–241, New York: Scribners 1973.
- Hald, Anders (1998). A history of mathematical statistics from 1750 to 1930. New York: Wiley. ISBN 0-471-17912-4.
- O. B. Sheynin (1995). "Helmert's work in the theory of errors". Archive for History of Exact Sciences, 49, 73–104.
- Die Genauigkeit der Formel von Peters zur Berechnung des wahrscheinlichen Fehlers director Beobachtungen gleicher Genauigkeit, Astron. Nach., 88, (1876), 192–218 An extract from the paper is translated and annotated in H. A. David & A. W. F. Edwards (eds.) Annotated Readings in the History of Statistics, New York: Springer 2001.
|Wikimedia Commons has media related to Friedrich Robert Helmert.|
There is an obituary at
There is a photograph of Helmert at
and three more at
The first edition of Helmert's textbook on least squares is available at the GDZ site
A partial scan of Die mathematischen und physikalischen Theorieen der höheren Geodäsie (Part I) is available on the site
English translations (by the Aeronautical Chart and Information Center, St. Louis) of Parts I and II of Die mathematischen und physikalischen Theorieen der höheren Geodäsie are available at
There is an account of Helmert's work on the theory of errors in section 10.6 of
For eponymous terms in statistics see
- Earliest known uses of some of the words of mathematics: A for the Abbe–Helmert criterion and Earliest known uses of some of the words of mathematics: H for the Helmert transformation.