Editing Karl Schwarzschild (section)

==Life==
Karl Schwarzschild was born on 9 October 1873 in [[Frankfurt|Frankfurt on Main]], the eldest of six boys and one girl,<ref name=":0">{{Cite web |title=The mystery of the dark bodies |url=https://www.mpg.de/11225504/the-mystery-of-the-dark-bodies |access-date=2022-05-15 |website=www.mpg.de |language=en}}</ref><ref>{{Cite web |title=Alfred Schwarzschild Biography |url=http://alfredschwarzschild.com/Alfred_Schwarzschild_Biography.html |access-date=2022-05-15 |website=alfredschwarzschild.com}}</ref> to [[History of the Jews in Germany|Jewish]] parents. His father was active in the [[business sector|business community]] of the city, and the family had ancestors in Frankfurt from the sixteenth century onwards.<ref>{{Cite book|url= https://www.worldcat.org/oclc/1244019080|title= "Nachforschung der Wahrheit" von der alten Lateinschule zum Lessing-Gymnasium in Frankfurt am Main : Festschrift zum 500-jährigen Jubiläum der Schule|date= 2020 |others=Bernhard Mieles, Carolin Ritter, Christoph Wolf, Lessing-Gymnasium Frankfurt am Main, Frankfurter Societäts-Medien GmbH|isbn=978-3-95542-379-7|location=Frankfurt am Main|oclc=1244019080}}</ref> The family owned two fabric stores in Frankfurt. His brother Alfred became a painter.<ref>{{Citation|last=Schwarzschild|first=Karl|title=Karl Schwarzschild Lectures|date= 1992|url= http://dx.doi.org/10.1007/978-3-642-58086-4_2|work= Gesammelte Werke Collected Works|pages= 29–42|place=Berlin, Heidelberg|publisher=Springer Berlin Heidelberg|doi=10.1007/978-3-642-58086-4_2 |isbn=978-3-642-63467-3|access-date= 2021-05-18}}</ref> The young Schwarzschild attended a Jewish primary school until 11 years of age<ref>{{Cite journal|date=2016-01-18|title=MacTutor History of Mathematics Archive|url= http://dx.doi.org/10.1108/rr-08-2015-0205|journal=Reference Reviews|volume=30|issue=1|pages=27–28|doi= 10.1108/rr-08-2015-0205|issn=0950-4125}}</ref> and then the [[Lessing-Gymnasium, Frankfurt|Lessing-Gymnasium]] (secondary school). He received an all-encompassing education, including subjects like Latin, Ancient Greek, music and art, but developed a special interest in [[astronomy]] early on.<ref>{{Cite book|url= https://www.worldcat.org/oclc/981916699|title=Karl Schwarzschild (1873-1916) ein Pionier und Wegbereiter der Astrophysik|date=2017|others=Klaus Reinsch, Axel Wittmann, Universitätsverlag Göttingen|isbn=978-3-86395-295-2|location=Göttingen|oclc=981916699}}</ref> In fact he was something of a child prodigy, having two papers on binary orbits ([[celestial mechanics]]) published before the age of sixteen.<ref>{{Cite journal|last= Hertzsprung|first= Ejnar|date= June 1917|title= Karl Schwarzschild|journal=The Astrophysical Journal |language= en|volume=45|pages=285|doi=10.1086/142329|bibcode= 1917ApJ....45..285H|issn=0004-637X|doi-access=free}}</ref>

After graduation in 1890, he attended the [[University of Strasbourg]] to study astronomy. After two years he transferred to the [[Ludwig Maximilian University of Munich]] where he obtained his doctorate in 1896 for a work on [[Henri Poincaré]]'s theories.

From 1897, he worked as assistant at the [[Kuffner Observatory]] in Vienna. His work here concentrated on the [[Photometry (astronomy)|photometry]] of star clusters and laid the foundations for a formula linking the intensity of the starlight, exposure time, and the resulting contrast on a [[photographic plate]]. An integral part of that theory is the [[Schwarzschild exponent]] ([[astrophotography]]). In 1899, he returned to Munich to complete his [[Habilitation]].

From 1901 until 1909, he was a professor at the prestigious [[Göttingen Observatory]] within the [[University of Göttingen]],<ref>{{Citation|last=Schwarzschild|first=Karl|title=Biography of Karl Schwarzschild (1873-1916)|date= 1992|url=http://dx.doi.org/10.1007/978-3-642-58086-4_1|work=Gesammelte Werke Collected Works|pages=1–28|place=Berlin, Heidelberg|publisher=Springer Berlin Heidelberg|doi=10.1007/978-3-642-58086-4_1 |isbn=978-3-642-63467-3|access-date=2021-05-18}}</ref> where he had the opportunity to work with some significant figures, including [[David Hilbert]] and [[Hermann Minkowski]]. Schwarzschild became the director of the observatory. He married Else Rosenbach, a great-granddaughter of [[Friedrich Wöhler]] and daughter of a professor of surgery at Göttingen, in 1909. Later that year they moved to [[Potsdam]], where he took up the post of director of the Astrophysical Observatory. This was then the most prestigious post available for an astronomer in Germany.{{citation needed|date= July 2021}}
[[File:Frederick Stratton, John William Nicholson, K. Schwarzschild, Frank Watson Dyson ride in automobile.jpg|alt=Schwarzschild, third from left in the automobile; possibly during the Fifth Conference of the International Union for Co-operation in Solar Research, held in Bonn, Germany|left|thumb|Schwarzschild, third from left in the automobile; possibly during the Fifth Conference of the International Union for Co-operation in Solar Research, held in [[Bonn, Germany]]]]
[[File:Grave of Karl Schwarzschild at Stadtfriedhof Göttingen 2017 01.jpg|thumb|Karl Schwarzschild's grave at [[Stadtfriedhof (Göttingen)]] ]]
[[File:Delegates to the Fourth Conference International Union for Cooperation in Solar Research at Mount Wilson Observatory.jpg|thumb|Schwarzschild at the Fourth Conference International Union for Cooperation in Solar Research at [[Mount Wilson Observatory]], 1910]]
From 1912, Schwarzschild was a member of the [[Prussian Academy of Sciences]].

At the outbreak of [[World War I]] in 1914, Schwarzschild volunteered for service in the [[Imperial German Army|German army]] despite being over 40 years old. He served on both the western and eastern fronts, specifically helping with [[Ballistics|ballistic calculations]] and rising to the rank of second lieutenant in the artillery.<ref name=":0" />

While serving on the front in Russia in 1915, he began to suffer from [[pemphigus]], a rare and painful autoimmune skin-disease.<ref name=":1">{{Cite web |title=Karl Schwarzschild - Important Scientists - The Physics of the Universe |url=https://www.physicsoftheuniverse.com/scientists_schwarzschild.html |access-date=2022-05-15 |website=www.physicsoftheuniverse.com}}</ref> Nevertheless, he managed to write three outstanding papers, two on the [[theory of relativity]] and one on [[Quantum mechanics|quantum theory]]. His papers on relativity produced the first exact solutions to the [[Einstein field equations]], and a minor modification of these results gives the well-known solution that now bears his name — the [[Schwarzschild metric]].<ref name="Levy">{{cite journal |last1=Levy |first1=Adam |title=How black holes morphed from theory to reality |journal=Knowable Magazine |date=January 11, 2021 |doi=10.1146/knowable-010921-1|s2cid=250662997 |doi-access=free |url=https://knowablemagazine.org/article/physical-world/2021/how-black-holes-morphed-theory-reality |access-date=25 March 2022}}</ref>

In March 1916, Schwarzschild left military service because of his illness and returned to [[Göttingen]]. Two months later, on May 11, 1916, his struggle with [[pemphigus]] may have led to his death at the age of 42.<ref name=":1" />

He rests in his family grave at the [[Stadtfriedhof (Göttingen)|Stadtfriedhof Göttingen]].

With his wife Else he had three children:

* [[Agathe Thornton]] (1910–2006) emigrated to Great Britain in 1933. In 1946, she moved to New Zealand, where she became a classics professor at the [[University of Otago]] in Dunedin.<ref>{{Cite web |last1=Graham |first1=Reg |last2=Taonga |first2=New Zealand Ministry for Culture and Heritage Te Manatu |title=Agathe Thornton |url=https://teara.govt.nz/mi/photograph/43514/agathe-thornton |access-date=2022-05-15 |website=teara.govt.nz |language=mi}}</ref>
* [[Martin Schwarzschild]] (1912–1997) became a professor of astronomy at [[Princeton University]].<ref>{{Cite web |title=Princeton - News - Princeton Astrophysicist Martin Schwarzschild Dies |url=https://pr.princeton.edu/news/97/q2/0411schw.html |access-date=2022-05-15 |website=pr.princeton.edu}}</ref>
* Alfred Schwarzschild (1914–1944) remained in Nazi Germany and was murdered during the [[The Holocaust|Holocaust]].<ref>{{Cite book |last1=Nicolini |first1=Piero |url=https://books.google.com/books?id=6B_UCgAAQBAJ&dq=alfred+schwarzschild+holocaust+son+of+karl&pg=PA10 |title=1st Karl Schwarzschild Meeting on Gravitational Physics |last2=Kaminski |first2=Matthias |last3=Mureika |first3=Jonas |last4=Bleicher |first4=Marcus |publisher=Springer |year=2015 |isbn=9783319200460 |pages=10}}</ref>