Friedrich robert helmert biography for kids

(b. Freiberg, Saxe, Germany, 31 July 1843; d. Potsdam. Germany. 15 June 1917)

geodesy, astronomy.

The youngest child of Johann Friedrich Helmert, treasurer of interpretation Johannishospitalgut of Freiberg, and shop the former Christiana Friederika Linke, Helmert attended the secondary institute in Freiberg and at dignity age of thirteen entered honourableness Annenrealschule in Dresden, where key older brother was assistant master.

In 1859 he began come near study engineering science at dignity Polytechnische Schule in Dresden. In that he was especially enthusiastic puff geodesy, his teacher, August Nagel, Saxon commissioner for the Mitteleuropäische Gradmessung, hired him, while sharptasting was still a student, save work on the triangulation not later than the coalfield of the Erzgebirge and the drafting of blue blood the gentry trigonometric network for Saxsony.

Imprisoned the summer of 1863 sand became Nagel’s assistant on honesty measurement of degrees. Helmert’s profession on this undertaking resulted come to terms with the Studien über rationelle Vermessungen der höheren Geodäsie (1868), organize which he received his Ph.D. from the University of Metropolis in 1867, after a year’s study of mathematics and astronomy.

Helmert next worked on the origin of a triangulation network warm up Leipzig under C.

Bruhns distinguished as a mathematics teacher parallel with the ground the Realinstitut run by Hölbe in Dresden; subsequently he participated in the discussion of backbreaking standard weights conducted by representation Commission on Standardization directed induce Nagel. At the beginning prop up 1869, after declining a literal offer from the observatory go back Leiden, he became an onlooker at the Hamburg astronomical lookout.

A product of his wait in Hamburg was Der Sternhaufen im Sternbilde des Sobieskischen Schildes (1874).

In 1870 Helmert became geodesy instructor at the newly supported technical school in Aachen, neighbourhood he was named professor mosquito 1872. At Aachen he congregate a collection of instruments, tumble a busy teaching schedule, cope with wrote his masterpiece.

Die mathematischen und physikalischen Theorien der höheren Geodäsie, which quickly made him known. He was an editor-in-chief of Zeitschrift für Vermessungswesen unearth 1876 to 1883 and stop in mid-sentence 1877 became a member lay out the Scientific Advisory Council designate the Prussian Geodetic Institute. Stylishness rejected offers from Córdoba, Argentina, in 1873 and from Karlsruhe in 1881.

Johann Jakob Baeyer dull in 1885, and in 1886 Helmert was appointed provisional chairman of the Prussian Geodetic Institution in Berlin, which was objective with the central office bring to an end the Europäische Gradmessung.

By greatness fall of 1886 he abstruse secured the appointment of first-class permanent secretary for the medial office, which thereby became wholly for the scientific tasks mean the Internationale Erdmessung. On 15 April 1887 Helmert was cut out for professor of advanced geodesy go on doing the University of Berlin dispatch, a week later, director sunup the Geodetic Institute; also mosquito 1887 he became a all-inclusive member of the Prussian Organizartion on Standards.

He suffered put in order stroke in 1916 and grand mal of its effects the mass year.

Helmert’s first wife was Designer Oehme, who died in 1887; his second was his niece Marie Helmert. By his secondly marriage he had a pin down, Robert.

Helmert’s abilities were summed engross in an obituary by Lowdown. Eggert:

Helmert possessed to a lighten degree the gift of spruce up vivid and clear delivery, which was especially easy to cotton on because of his straightforward accept.

He was able to holiday mathematical developments in an supremely clear manner.... That he could hold the interest of different students... is evident from pure series of dissertations which resulted from his influence. Those flawless his students who... had rectitude good fortune to come penetrate close contact with Helmert option always gratefully recall the cordial and sympathetic support that they found during their studies misstep him [Zeitschrift für Vermessungswesen, 46 (1917), 294–295].

Helmert received many honors.

In 1884 he became exceeding honorary member of the Deutsche Geometerverein; in 1900 he became a full member of honourableness Prussian Academy of Sciences take Berlin, and in 1903 token doctor of engineering of illustriousness Aachen Technische Hochschule. Besides wretched twenty-five German and foreign trappings, in 1912 he was awarded the Goldene Medaille für Wissenschaft.

In his dissertation Helmert developed blue blood the gentry theory of the ellipse be frightened of error and of the psyche points error; he also burned the most advantageous division set in motion the work of measuring.

Name 1872 his Die Ausgleichsrechnung nach der Methode der kleinsten Square mit Anwendungen auf die Geadäsie und die Theorie der Messinstrumente appeared. In this work Helmert introduced a new theory break into equivalent observations and for honesty first time used the family of least squares in rendering examination of measuring instruments.

Übergangskurven für Eisenbahngeleise (1872) elitist Günstige Wahl der Cardinalpunkte beim Abstecken einer Trace (1875) resulted from his teaching at Aken. A wealth of specialized documents served as preparation for top masterpiece, Die mathematischen und physikalischen Theorien der höheren Geodäsie, trumped-up story which he worked from 1877.

In part 1 of that toil.

Die mathematischen Theorien (1880), Helmert demonstrated the validity of Elegant. M. Legendre’s theorem for highly sensitive triangles and treated extensively nobleness geodesy of the sphere skull the slightly oblate ellipsoid discount rotation; he linked geodesy damage the actual surface of position earth by means of plumb-line deflection.

He discussed for picture first time calculation on description ellipsoid with chords, the penetration formulas for geodetic lines, enjoin the development of series fail to appreciate use in the computation assault distances and azimuths from geographical positions. He also considered class geodetic lines between two just about diametrical points, the maximum logic of the higher terms pass judgment on Legendre’s theorem, and the globular computation of chains of triangulation.

In addition he discussed influence relationships between rectangular and geographic coordinates, the balancing of geodetic-astronomic measurements with regard to plumb-line deflections, and developments regarding dignity conclusiveness of measurements of scale 1 for representing the earth’s transform as that of an spheroidal of rotation.

Part 2, Die physikalischen Theorien (1884), discusses the vigorous of the earth from say publicly standpoint of potential theory, come across with the analytical formulation look up to the concept of the speeding of gravity and the unveiling of its potential.

There gos next a treatment of the accepted properties of equipotential surfaces significant of their discontinuities of turnout. After a presentation of Clairaut’s theorem Helmert derives the flattening of the sphere of rendering earth from 122 pendulum stage. He finds it to eke out an existence 1:299.26 ± 1.26, reduced rear sea level, allowing for position condensation of the visible upsetting masses of the earth’s integument to a surface parallel cut short the surface of the expanse, at a depth of join miles.

He finds gravity mad sea level to be 9.7800 (1 + 0.005310 ± 14 sin²B). He also investigates blue blood the gentry perturbation effect of the pentad continents, considered as blunted diskshaped cones 4,000 meters thick, lose control the level planes near integrity surface and of other traumatic masses of various shapes.

Along nuisance the temporal changes of influence level planes, Helmert discusses rendering disturbances of the plumb underline resulting from the moon queue the sun, as well brand from the small movements unmoving the earth’s axis.

Next of course takes up the value closing stages astronomical data for knowledge get through the earth’s shape. In position section entitled “Das geometrische Nivellement” he insists on taking bump into account the variation of significance with geographical latitude but deems the influence of gravity anomalies to be unimportant. In treating trigonometric altimetry he also considers lateral refraction and aberration.

Intensity opposition to the trigonometric means for determining the geoid, let go holds that the method loosen plumb-line deflections in the donkey-work of meridian profiles by implementation of closely spaced stations disseminate latitude, for which he proposes the term astronomisches Nivellement, job more advantageous.

In 1886, for distinction Prussian portion of the Mitteleuropäische Gradmessung, Helmert provided for glory establishment of the plumb-line deflections of a net of cardinal points centered on Point Rauenberg, near Berlin; for the boundless measurements of latitudes and azimuths, telegraphic measurements of lengths were, in part, also executed.

Enclose October 1887 Helmert delivered come to an end the commissioners of the Hymn Erdmessung, in “Lotabweichungen I,” justness formulas and tables, with examples of their use, necessary shelter calculation of the plumb-line deflections. In 1890 he reported write off the variations of geographical line in 1889, which, in 1891, he attributed to changes all but position of the earth’s alignment.

In addition, he arranged in favour of an expedition to Honolulu existing inspired the establishment of grandeur International Bureau of Latitudes connected with monitor the movements of rank poles.

When Sterneck measured gravity territory his pendulum apparatus (constructed burst 1887), Helmert made a dense evaluation of Sterneck’s methods show consideration for measurement and investigated the trigger off of the gravitational disturbances (“Die Schwerkraft im Hochgebirge,” 1890); solution addition, he carried out cap own measurements with this keep under surveillance beginning in 1892.

In 1893–1894 he made test measurements meet the reversible pendulum supplied offspring J. A. Repsold in Hamburg; in 1898 he collected glory results in Beiträige zur Theorie des Reversionspendels. They constituted rectitude basis for the determination warm absolute gravity by Friedrich Kühnen and Philipp Furtwängler between 1900 and 1906 at the Potsdam Geodetic Institute.

The value exact in 1906, 981.274 ± 0.003 gal was accepted in 1909 by the Internationale Erdmessung

Helmert was always concerned with improvements rotation the gravitational formula and dupe the reduction of determinations refreshing gravity (1901–1904, 1915). In 1909 he calculated the value pay money for the flattening of the world as 1:298.3 ±t 0.7 (as opposed to J.

F. Hayford and William Bowie, whose personage [1912] was 1:298.4 ± 1.5). He investigated the state run through equilibrium of the masses slant the earth’s crust (1908, 1912), the depth of the isostatic surface according to J. Pirouette. Pratt’s isostasy hypothesis (1909), accept the accuracy of the extent of Hayford’s ellipsoidal earth (1911).

In 1915 he made class ellipticity of the equator likely, although he was unable face up to complete these studies.

BIBLIOGRAPHY

I. Original Scrunch up. Helmert’s publications are listed false Poggendorff, III, 610–611; IV, 611–612; V, 516–517; VI, 1076. Surmount articles appeared chiefly in Zeitschrift für Vermessungswesen, Astronomische Nachrichten, Sitzungsberichte der Preussischen Akademie der Wissenschaften zu Berlin, and Verhandlungen ball Internationalen Erdmessung.

Important works call mentioned in the text complete Instrumente für hoühere Geodäsie (Brunswick. 1878): Übersicht der Arbeiten nonsteroid Geodätischen Instituts unter Generallieutnant Baeyer (Berlin, 1886); Das kgl. Preussische Geodätische Institut (Berlin, 1890); Die europäische Längengradmessung in 52° Breite von Greenwich bis Warschau.

Unrestrained Hauptdreiecke und Grundlinienanschlüsse von England bis Polen (Berlin, 1893); Zenitdislanz und Bestimmung der Höhenlage balance Nordsee-Inseln Helgoland... (Berlin, 1895); “Geodäsie und Geophysik.” in Enzyklopädie spool mathematischen Wissenschaften, VI, 1, supp. 2 (Leipzig, 1910); and “Die internationale Erdmessung in den ersten 50 Jahren ihres Bestehens,” middle International Monatssehrift für Wissenschaft, Kunst und Technik (1913).

II.

Secondary Belles-lettres. Obituaries include O. Eggert, tabled Zeitschrifi für Vermessungswesen, 46 (1917), 281–295; O. Hecker, in Beiträgen zur Geophysik, 14 , maladroit thumbs down d. 4 (1918); L. Krüger, collect Astronomische Nachrichten, 204 (1917); Mixture. Schmidt, in Jahrbuch der Bayerischen Akademie der Wissenschaften (1917), 53–58; and R.

Schumann, in Oüsterreichische Zeitschrift für Vermessungswesen 15 (1917), 97–100. See also W. Chemist, “Helmert,” in Gedenktage des mitteldeutschen Raumes 1967 (Bonn, 1967), pp. 32–34, 63–64; Paul Gast, “Der Lehrstuhl für Vermessungskunde (Lehrstuhl Helmert),” in his Die Technische Hochschule zu Aachen 1870–1920 (Aachen, 1920), pp.

247–250; H. Peschel, “Gendenkrede zu Helmerts 50. Todestag crew 15. Juni 1967 in Freiberg,” in Vermessungstechnik, 15 (1967), 334–340; and Rudolf Sigl, in Neue deutsche Biographie, VIII (1969), 497–498.

Walther Fischer