Some Amazing Facts About the Great Scientist Karl Schwarzschild
Introduction
Karl Schwarzschild, the famous Astrophysicist, belonged to a Jewish family. He was the eldest son of his parents, Henrietta Sabel and Moses Martin Schwarzschild. His contributions in various fields of Physics and astronomy have been very significant. Let us look into his life more closely and discover some amazing facts of this wonderful scientist.
A Brief Biography of Karl Schwarzschild
**
Birth: October 9, 1873
Place of Birth: Frankfurt am Main
Ethnicity: White
Education: Jewish Primary School in Frankfurt
Higher Education from University of Strasbourg
Doctorate from University of Munich
Positions: Assistant at Kuffner observatory (1897)
Professor at Gottingen (19011909)
Astrophysical Observatory (1909)
Member of Prussian Academy of Sciences (1912)
Karl Schwarzschild died on May 11, 1916 struggling with a rare skin disease ‘pemphigus’.
Famous for: Karl is known for providing solution to Einstein’s field Equation for general relativity, with respect to a single spherical nonrotating mass. This is popularly known as the Schwarzschild black hole.
{Image sources: Above right: Karl Schwarzschild:https://www.aip.de/image_archive/images/karl_schwarzschild.jpg}
Image sources: Below right: Credit: N. Rumiano, Source: https://www.daviddarling.info/encyclopedia/S/Schwarzschild_black_hole.html}
Notable Achievements

Karl Schwarzschild provided the Schwarzschild solution to measure the Schwarzschild radius, the size of the event horizon of a stationary
black hole by using Schwarzschild coordinates.

Karl Schwarzschild researched in various fields of science including celestial mechanics, quantum mechanics, stellar structure, instrumental astronomy, Halley’s comets and spectroscopy.

His research work in geometrical deviations in the optical system devised a formula to calculate the optical density of photographic material. The exponent used in this formula is now known as the ‘Schwarzschild exponent’. By using this formula, it became possible to get precise photographic measurements of intensities of even faint astronomical sources. This has been one of his major achievements.

Karl Schwarzschild was the first scientist who introduced correct Lagrangian formalism of the electromagnetic field.

While serving in the war front, he produced exact solutions to some of Einstein’s work in relativity theory using field equations. Einstein himself praised Karl for his excellent work.

“Inner Schwarzschild solution” is universal for solids, fluids, gases, Sun and stars. It is used successfully for measuring Schwarzschild radius of a nonrotating black hole, with the help of Schwarzschild coordinates and Schwarzschild metrics.

While suffering from the painful disease, pemphigus, Karl Schwarzschild wrote three marvelous papers, two on relativity theory and one on quantum theory. The papers on relativity theory provided an exact solution to the Einstein field equations and were called “Schwarzschild metric”.
{Above right: Image Credit: Schwarzschild radius: Source: https://www.odec.ca/projects/2007/joch7c2/Karl_Schwarzschild.html}
Honors for Karl Schwarzschild
To recognize the great work of Karl Schwarzschild, many things were named after him. These include:
 Karl Schwarzschild Medal
 Karl Schwarzschild Observatory
 Schwarzschild coordinates
 Schwarzschild metric
 Schwarzschild (crater)
 Schwarzschild radius
 Schwarzschild wormholes
 Schwarzschild effect
Some Other Interesting Facts of His Life
 All other of his family members were interested in art and music and he was first to become a scientist in his family.
 He used his pocket money to buy material for constructing his first telescope.
 Paul Epstein, his professor’s son was his friend, and both were interested in astronomy.
 Karl learned how to use the telescope and some advanced mathematics from his friend Paul Epstein.
 In 1914, when Europe was deeply involved in World War I, Karl Volunteered to join the German Army at the age of 41. Serving in both Northern and Eastern fronts, he was promoted to the rank of Lieutinent in artillery.
 On 22nd October 1909, he married Else Posenbach, the daughter of a professor of surgery at the University of Gottingen.
 Karl Schwarzschild had three children who were called Agathe, Martin and the youngest, Alfred. Martin, his second son, became a professor of astronomy at Princeton.
 In 1959, the German Astronomical Society established a lectureship and the Karl Schwarzschild Medal in his honour. His son Martin was the first recipient of this medal.
Karl Schwarzschild reached to the heights of achievements which very few people reach. He was a man with deep insight and very wide scientific interests. Such people are born once in an era!
References
https://wwwhistory.mcs.stand.ac.uk/Biographies/Schwarzschild.html
https://zelmanov.pteponline.com/papers/zj2008b3.pdf
https://www.odec.ca/projects/2007/joch7c2/Karl_Schwarzschild.html
https://www.daviddarling.info/encyclopedia/S/Schwarzschild_black_hole.html