Johann Georg von Soldner

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JG Soldner, first director of the Bogenhausen observatory, based on a portrait from 1816, source: Bavarian Academy of Sciences, Munich

Johann Georg Soldner , since 1825 Johann Georg von Soldner , (born July 16, 1776 in Georgenhof near Feuchtwangen , † May 13, 1833 in Bogenhausen near Munich ) was a German physicist , mathematician , astronomer and geodesist . He developed the Soldner coordinate system for precise national surveys .

Life

He was born on July 16, 1776 on the Georgenhof near Feuchtwangen in the Central Franconian district of Ansbach as the son of the farmer Johann Andreas Soldner. He received two years of instruction at the Feuchtwang Latin School. He showed a gift for mathematics early on: he used self-made instruments to measure his father's fields and all night he studied mathematical textbooks and maps. Since he had never attended high school, he began in 1796 with private studies of languages ​​and mathematics with Julius Conrad von Yelin in Ansbach. When the Margraviate of Ansbach was ceded to Prussia in 1791 , Soldner became a Prussian citizen and went to Berlin in 1797 , where he was employed as a geometer by the astronomer Johann Elert Bode , the director of the Berlin observatory , and carried out astronomical and geodetic studies there. In 1803 he was awarded the degree of Dr. phil. awarded. After rejecting an appointment to the university observatory in Moscow, he worked from 1804 on preparing the triangulation of the Principality of Ansbach, which at that time still belonged to Prussia. From 1804 to 1806 he was in charge of surveying the Principality of Ansbach. Here he met Ulrich Schiegg , who had previously been an astronomer at the Munich observatory and had been removed from his position there as an astronomer due to intrigues in 1805.
As a result of the politico-military situation at the beginning of the 19th century, the Bavarian land surveying was systematized under the direction of French soldier engineers. The necessary foundations for successful surveying work could only be created on the basis of astronomical location determinations. Therefore, the ex-benedictine and astronomer Ulrich Schiegg was appointed court astronomer to Munich. In January 1803 he built a small observatory in the north-west tower of the former Jesuit college in Neuhauser Strasse - the Bavarian Academy of Sciences has been located here since 1783 . However, Schiegg's cooperation with the French geodesists was not always problem-free and when he justifiably drew attention to discrepancies in their measurements, he was removed from his position at the instigation of the French in March 1805. Schiegg had turned down the offer of a professorship in Würzburg and was instead surprisingly appointed head of land surveying in the newly acquired Franconian territories. His outstanding achievement was the measurement of the almost 13.8 km long Franconian base between Nuremberg-St. Johannis and Bruck (now in Erlangen) with the help of a measuring device made in the Reichenbach workshop. The astronomer Karl Felix von Seyffer , who had excellent connections to the French army command, was appointed Schiegg's successor at the Munich observatory . Seyffer had given up his position as associate professor in Göttingen in 1804 and in 1805 joined Napoleon Bonaparte as Ingénieur-Géographe in his headquarters. There he came into contact with the government of the later newly founded Kingdom of Bavaria. The same took him into her service; In 1808 he became councilor and member of the statistical and topographical bureau in the Ministry of Foreign Affairs and in 1815 director of this institution. The Bavarian tax cadastre, which was trend-setting in Germany at the time, goes back to Seyffer. Seyffer received an order from Elector Max IV. Joseph to build a larger observatory. He then immediately had Schiegg's instruments transported to a wooden hut on the chosen spot between the villages of Ramersdorf and Haidhausen , but the whole thing was not pursued any further. Only when this makeshift observatory became an attribute of the restructured academy in 1807 did the matter move: Several astronomical instruments were ordered from the up-and-coming precision mechanical-optical workshop of Utzschneider , Reichenbach and Liebherr in Munich, as the existing ones were meanwhile out of date. The elevation of Bavaria to a kingdom on January 1, 1806 and the resulting increased need for representation initially had a positive effect on the progress of things. After the instruments were delivered in 1811 and 1812, however, it was found that they could not be set up optimally in the existing temporary structure. So people became more and more friends with the idea of ​​building a new stone building, possibly even in another place. Financing problems, but also Seyffer's inaction in the astronomical field, denounced by his contemporaries, delayed the matter more and more. Seyffer, whose interests actually lay more in the field of surveying, was finally dispensed from his astronomical duties in 1813 and finally dismissed as court astronomer at the end of 1815. The physicist and mathematician Anselm Ellinger (1758–1816) was appointed his deputy during this time. In 1808 Schiegg had already been called back to Munich to develop an organization and work plan for the cadastre creation of the tax surveying commission founded in the same year and led by Joseph von Utzschneider . He also campaigned for the employment of Johann Georg Soldner, who was to shape the theoretical foundations of land surveying in the long term. Utzschneider brought Soldner to Munich in 1808 and hired him as a trigonometer for the newly established tax assessment commission. In 1815 Soldner was appointed royal court astronomer and on April 1, 1816, was appointed Seyffer's successor. Soldner had been working for the Tax Surveying Commission in Munich since 1808, where he laid the theoretical foundations for Bavarian land surveying. Compared to the protracted history of the creation of the observatory, events almost precipitated each other: on April 18, 1816, the academy submitted construction plans, which presumably still came from Seyffer, and on June 4, 1816, King Max I. Joseph commissioned the building the new observatory and on August 11, 1816 the first groundbreaking took place on a small hill east of the village of Bogenhausen . In the end, a new location was also chosen. Under the direction of the royal court building inspector Franz Thurn, the work progressed rapidly and the shell was completed by November 15, 1817. The interior work and the installation of the instruments then took almost two years to complete. The layout of the horseshoe-shaped facility with the meridian hall that was common at the time in the center and two observation towers at the side housed the best instruments that could be purchased at the time. The set of instruments was crowned by a meridian circle from the Mathematical-Mechanical Institute von Reichenbach and Ertel . Routine work with this instrument began in December 1819. The best-equipped observatory in the world, the Königliche Sternwarte zu Bogenhausen , was put into operation: the Reichenbach and Ertel meridian circle was one of the best meridian circles in the world when it was delivered in 1819, as it was divided into circles Reichenbach's famous circle dividing machine, which improved the declination determination of stars by a factor of 10.



Soldner saw his main task at the newly built observatory in helping to secure the fundamentals of astronomy through numerous measurements of the positions of the sun, moon, planets and fundamental stars. But this routine was soon interrupted for a short time when, in March and April 1820, Joseph von Fraunhofer continued the spectroscopic investigations of planets and bright stars with his new apparatus installed in the west tower of the observatory for experiments on the nature of the light of fixed stars, which he carried out in 1814 had started at the Optical Institute in Benediktbeuern . In these spectra he had found dark lines similar to those he had already discovered in large numbers in the spectrum of the sun , measured precisely and published in 1817. Soldner assisted him in his experiments in Bogenhausen, which, in addition to the micrometric determination of the position of the lines in the Sirius spectrum, also included investigations into the question of the different diffractibility of the light of different colored stars. Thus, the observatory in Bogenhausen became the first observatory in the world in which spectroscopic observations of the stars were made. In 1827 the observatory was subordinated to the newly founded General Conservatory of the State's Scientific Collections. From 1828 Soldner was no longer able to fully meet his duties due to a liver disease, so his young assistant Johann von Lamont ran the observatory under his supervision. After Soldner's death in 1833, the Scot Lamont was initially appointed provisional director of the observatory and in July 1835, against strong competition, became curator and director of the observatory. He continued the spectroscopic investigations with his new giant telescope from the former Fraunhofer workshop, which was delivered in the same year and housed in a separate building on the grounds of the observatory.

Grave plaque for Soldner

In 1825, Soldner was awarded the personal title of nobility for his services to the theoretical foundations for Bavarian land surveying . Soldner was buried in the Bogenhausen cemetery on the west side of the Church of St. George (honorary grave). There is a memorial plaque above his grave on the western outer wall, installed by the royal cadastral office in 1892.

That Soldner was not an unknown scientist is shown by the fact that in 1815 the position in Mannheim was up for grabs. In 1806 the Grand Duchy of Baden took over the areas of the Electoral Palatinate on the right bank of the Rhine and thus also the observatory. The court astronomer Roger Barry resumed his observations, but fell ill in 1810 and the observatory remained unused until his death in 1813 and thus lagged behind its brilliant beginnings. Famous astronomers could either not be retained , such as Heinrich Christian Schumacher (1813–1815 in Mannheim), who founded the oldest still existing specialist journal on astronomy, the Astronomical News , at his subsequent place of work in Altona , or were deterred by unskillful personnel policy despite interest. like Friedrich Wilhelm Struwe , who then set up a renowned observatory in Pulkowa near Saint Petersburg. In 1815 an attempt was made to move Johann Georg von Soldner to Mannheim; However, this also canceled. From 1816 until his death in 1846, Bernhard Nicolai was court astronomer who mainly devoted himself to the orbits of comets.

Because Napoleon needed maps suitable for military use for his campaigns, a Commission des Routes was set up in Munich and entrusted with the topographical mapping of Bavaria. When the French troops left Bavaria after the Peace of Lunéville on February 9, 1801, the work that had begun on a map of the whole of Bavaria was incomplete. The idea of ​​a comprehensive, precise map of Bavaria was however in the room. Statements and demands such as "rapid production of a map of Bavaria" or "très grand intérêt à la plus prompt conception possible d'une Carte exacte du Cercle de Bavière" increased in 1801 and finally led to the establishment of the Topographical Bureau by Elector Max IV Joseph, later King Max I, on June 19, 1801. This day is therefore considered to be the founding date of the Bavarian Surveying Administration. Finally, the efforts ended in the Bavarian premiere , which was ordered by King Maximilian I Joseph in 1808 and lasted until 1864.
The tasks of the Topographical Bureau consisted mainly in the continuation and completion of the work begun in 1800, the topographical mapping of the state and the representation of Bavaria in topographical maps.

plant

The Soldner coordinate system goes back to Soldner, among other things , which was used in large parts of Germany until the 20th century, in the state of Berlin even in the 21st century. Mathematically, he dealt with the integral logarithm and wrote the work Théorie et tables d'une nouvelle fonction transcendante in 1809 . Soldner was the first who, according to Lorenzo Mascheroni (1790), calculated Euler's constant γ = 0.57721 ... to 22 correct decimals (1809).

Controversy over light deflection

In 1804 (written in 1801) he published a work in which, based on Newton's corpuscle theory of light, he concluded that light would be deflected by massive celestial bodies, using Newton's law of gravitation using the mass-independent classical equations of motion for deflection by the sun received the value of 0.84 arc seconds. Soldner wrote:

“So when a ray of light passes a celestial body, it is compelled by the attraction of the same, instead of going in the straight direction, to describe a hyperbola, the concave side of which is directed towards the attracting body. […] If one substitutes the acceleration of gravity on the surface of the sun for tang ω in the formula and assumes the radius of this body for the unit, one finds ω = 0.84 ″. If one could observe fixed stars very close to the sun, one would have to take this into consideration. But since this does not happen, as is well known, the perturbation caused by the sun is negligible. "

In his first work on general relativity (1908, 1911) Albert Einstein received the same value for distraction. However, with the further development of the theory, this work proved to be inadequate and in 1916 Einstein finally achieved a deflection of 1.75 ", i.e. about twice as large as Soldner's value. As a result, in 1921 the Einstein and relativity opponent Philipp Lenard ordered a reprint of Soldner's Work in the Annalen der Physik , with the intention of undermining Einstein's priority, to present an alternative to the ART and to point out a possible plagiarism of Einstein. However, this was rejected by Max von Laue and others immediately, because Soldner's value on the one hand half as much was great like Einstein's, and because the bases of the theories are completely different so it makes no sense to compare them.Modern measurements confirm Einstein's value.

Trivia

  • From the estate of Carl Friedrich Gauß in the Lower Saxony State and University Library in Göttingen, ten letters from Soldner dated December 15, 1814 to December 26, 1823 have been preserved.
  • In 1817, at the request of court astronomer Johann Georg Soldner, Joseph Fraunhofer was appointed a corresponding member of the academy (due to quarrels about his lack of scientific training, extraordinary member and curator of the physical cabinet only from 1821)
  • As the first director of the Royal Observatory in Bogenhausen, he had a close friendship with Joseph Fraunhofer and in this context he became a co-founder of a pioneering, new astronomical investigation method, spectroscopy . But Soldner was wrong in assessing the importance of the investigations made. Little did he suspect that the research into the properties of dark lines in the star spectra laid the foundation for one of the most important observation methods in modern astrophysics, the triumph of which continues to this day. So the experiments at the Royal Observatory in Bogenhausen were stopped and Soldner devoted himself to the measurement of the positions of the sun and the most important planets from 1820 on the systematic weather observation.
  • Soldner can be seen as the creator of the scientific basis of Bavarian land surveying. He created the mathematical basis for the area-wide surveying of Bavaria. He realized that a sphere can be used as a reference body instead of the earth ellipsoid used by Laplace to depict the Bavarian region . Its so-called Soldner sphere enables much simpler calculations when depicting the land maps. As the zero point for his coordinate system, Soldner chose the helmet pole of the northern tower of the Munich Frauenkirche ; from 1801 to 1927 it was the zero point for the first Bavarian land survey based on the Bavarian Soldner coordinate system. This is where the horizontal and vertical coordinate axes intersect, which have been dividing the Bavarian land maps into four regions for over 200 years: Northwest (NW), Northeast (NE), Southeast (SE) and Southwest (SW).
  • The Soldner coordinate system was used in large parts of Germany until the 20th century, in Berlin it was used until the 21st century. With his coordinate system, Soldner created the mathematical basis for the area-wide surveying of Bavaria. Many countries also took advantage of these advantages. When designing the Prussian real estate cadastre, it was also decided to use the Soldner coordinate system, as it is easy to use computationally when measuring items. On December 29, 1879, the Central Directorate of Surveying in Prussia prescribed the use of points I and II of the Prussian national triangulation as the zero point of the payroll systems. The limitation in width resulted in 40 local coordinate systems, each with a trigonometric point as the origin. The European Terrestrial Reference System 1989 (ETRS89) - the official reference system - has also been used in the State of Berlin since 2010 . In the transition between Gauß-Krüger zones 4 and 5 for the real estate cadastre , the 18th Soldner coordinate system of the Prussian cadastral survey, established in 1879 and originating in the trigonometric point I. order Müggelberg, was still in use until July 20, 2015 .
  • In addition to Soldner, the famous astronomers and directors of the royal observatory Johann von Lamont , Hugo von Seeliger and Alexander Wilkens rest in the cemetery in Bogenhausen .

Honors

Memorial for Soldner in front of the State Office for Surveying and Geoinformation in Munich
  • 1813: Member of the Bavarian Academy of Sciences
  • 1825: appointed member of the London Astronomical Society
  • 1825: Knight's Cross of the Bavarian Order of Civil Merit associated with the personal nobility
  • 1829: Knight's Cross of the French Legion of Honor
    Memorial plaque for Soldner at the house where he was born
  • 1912: Memorial plaque on the house where he was born by the Association of Higher Bavarian Surveyors
  • 1956: On April 7, 1956, a street in Fürth was named after him. There is also a primary and secondary school in Soldnerstrasse .
  • 1960: There is a Soldnerweg in Bogenhausen .
  • 1962: Monument in Munich: on the corner of Oettingenstraße and Liebigstraße - in the immediate vicinity of the State Office for Surveying and Geoinformation in Munich - a monument was erected in honor of Soldner. The monument, designed and executed by the sculptor Rolf Nida-Rümelin , symbolizes the relationship between the earth's ellipsoid and the Soldner's sphere, which encloses the earth's ellipsoid. The work of art consists of a massive ball made of Nagelfluh , a monolith with a diameter of 2.20 m and honors the work of Johann Georg von Soldner. A bronze band runs around its equator, it bears figures which indicate the work of the surveyors and the inscription related to the astronomer and geodesist Soldner
"Caelum dimensuravi tellusque Bavariae" - I measured the stars and the state of Bavaria .
  • The Johann-Georg-von-Soldner-Realschule Feuchtwangen is named after him in Feuchtwangen . There is a Soldner thaler as a reward for special successes.
  • There are Soldnerstrasse in Augsburg and Mannheim ,
  • Von-Soldnerstrasse in Feuchtwangen and Kassel

Publications

  • Soldner, JG v .; (Lenard, P.): About the deflection of a ray of light from its rectilinear movement by the attraction of a cosmic body, which it passes close; . In: Annals of Physics . 65, 1921, pp. 593-604. doi : 10.1002 / andp.19213701503 .
  • JG v. Soldner: Théorie et tables d'une nouvelle fonction transcendante . J. Lindauer , Munich 1809 ( uni-goettingen.de ).
  • JG v. Soldner: Theory of land surveying (1810). Edited by J. Frischauf. Ostwald's classic 184, Leipzig 1911

Individual evidence

  1. ↑ Land surveying and geographic base information Brandenburg (ed.): On the trail of land surveying in Berlin and Brandenburg. , Berlin March 2014, ISBN 978-3-7490-4187-9 ; Page 22
  2. ^ Karl Maximilian von Bauernfeind :  Soldner, Johann Georg von . In: Allgemeine Deutsche Biographie (ADB). Volume 34, Duncker & Humblot, Leipzig 1892, pp. 557-563.
  3. ^ Karl Maximilian von Bauernfeind : Johann Georg von Soldner and his system of Bavarian land surveying. Lecture given at the end of year celebration of the Royal Technical University in Munich on July 27, 1885. With JG Soldner's portrait . Franz'sche, Munich 1885.
  4. ^ Kai Budde: Mannheim Observatory, History of the Mannheim Observatory 1772–1880, State Museum for Technology and Work in Mannheim, regional culture publisher 2006, page 135
  5. ↑ Soldner 1804
  6. ↑ Soldner 1921
  7. ↑ Max von Laue : Reply to Mr. Lenard's preliminary remarks on Soldner's work from 1801 . In: Annals of Physics . 66, 1921, pp. 283-284. doi : 10.1002 / andp.19213712005 .
  8. ↑ Jaki, SL: Johann Georg von Soldner and the Gravitational Bending of Light, with an English Translation of His Essay on It Published in 1801 . In: Foundations of Physics . 8, 1978, pp. 927-950. doi : 10.1007 / BF00715064 .
  9. ↑ Treder, HJ; Jackisch, G .: On Soldner's Value of Newtonian Deflection of Light . In: Astronomical News . 302, 1981, pp. 275-277. bibcode : 1981AN .... 302..275T .
  10. ↑ Will, CM: Henry Cavendish, Johann von Soldner, and the deflection of light . In: Am. J.Phys. . 56, 1988, pp. 413-415. doi : 10.1119 / 1.15622 .
  11. ↑ Will, CM: The Confrontation between General Relativity and Experiment . In: Living Rev. Relativity . 9, 2006.
  12. ↑ http://kalliope-verbund.info/de/ead?ead.id=DE-611-HS-3211584 digitized available
  13. ↑ https://www.hdbg.eu/koenigreich/web/index.php/haben/index/herrscher_id/1/id/27
  14. ↑ https://www.fuerthwiki.de/wiki/index.php/Soldnerstra%C3%9Fe
  15. ↑ http://www.gs-soldner-fuerth.de/
  16. ↑ http://www.soldnerschule.de/
  17. ↑ http://www.realschule-feuchtwangen.de/index.php/schulprofil/soldner-taler

literature

  • Martin Beblo:  Soldner, Johann Georg von. In: New German Biography (NDB). Volume 24, Duncker & Humblot, Berlin 2010, ISBN 978-3-428-11205-0 , pp. 547-549 ( digitized version ).
  • Torge, Wolfgang: History of geodesy in Germany. Berlin, de Gruyter, 2007
  • Blaser, Franz: Soldner coordinates and reduction of measured distances and direction angles, communications from surveying Berlin 1977, No. 7
  • Blaser, Franz: Coordinate Systems and Layer Networks in Berlin, Messages from Surveying Berlin 1992, No. 19
  • W. Bachmann: The attributes of the Bavarian Academy of Sciences 1807-1827. Munich Historical Studies, Department of Bavarian History, Volume 8, Kallmünz 1966
  • R. Häfner, R. Riekher: The pioneers of star spectroscopy. The stellar spectroscopic investigations by Fraunhofer (1816–1820) and Lamont (1836). In: Acta Historica Astronomiae Vol. 18, 2003; Pages 137-165
  • R. Häfner: The Munich University Observatory in the course of its history. Munich 2003
  • K. Winschiers: 500 years of measurement a. Map in Bavaria, an overview in 60 biograph. Sketches, 1982; Pp. 133-136
  • State of Brandenburg, LGB (Land surveying and geographic base information Brandenburg): On the trail of land surveying in Berlin and Brandenburg. Potsdam March 2014, ISBN 978-3-7490-4187-9
  • Günther, Seyffer, Karl Felix von in: Allgemeine Deutsche Biographie 34 (1892), pp. 107-108

Web links

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personal data
SURNAME Soldner, Johann Georg von
BRIEF DESCRIPTION German physicist, mathematician and astronomer
DATE OF BIRTH July 16, 1776
PLACE OF BIRTH Georgenhof
DATE OF DEATH May 13, 1833
Place of death Bogenhausen