|Who is it?||Physicist|
|Birth Day||March 12, 1824|
|Birth Place||Königsberg, Kingdom of Prussia, German|
|Age||195 YEARS OLD|
|Died On||17 October 1887(1887-10-17) (aged 63)\nBerlin, Province of Brandenburg in the Kingdom of Prussia, a part of the German Empire\n(present-day Germany)|
|Alma mater||University of Königsberg|
|Known for||Kirchhoff's circuit laws Kirchhoff's law of thermal radiation Kirchhoff's laws of spectroscopy Kirchhoff's law of thermochemistry|
|Awards||Rumford medal (1862) Davy Medal (1877) Matteucci Medal (1877) Janssen Medal (1887)|
|Institutions||University of Berlin University of Breslau University of Heidelberg|
|Doctoral advisor||Franz Ernst Neumann|
|Notable students||Loránd Eötvös Edward Nichols Gabriel Lippmann Dmitri Ivanovich Mendeleev Max Planck Jules Piccard Max Noether Heike Kamerlingh Onnes Ernst Schröder|
Kirchhoff formulated his circuit laws, which are now ubiquitous in electrical engineering, in 1845, while still a student. He completed this study as a seminar exercise; it later became his doctoral dissertation. In 1857 he calculated that an electric signal in a resistanceless wire travels along the wire at the speed of light. He proposed his law of thermal radiation in 1859, and gave a proof in 1861. He was called to the University of Heidelberg in 1854, where he collaborated in spectroscopic work with Robert Bunsen. Together Kirchhoff and Bunsen discovered caesium and rubidium in 1861. At Heidelberg he ran a mathematico-physical seminar, modelled on Neumann's, with the Mathematician Leo Koenigsberger. Among those who attended this seminar were Arthur Schuster and Sofia Kovalevskaya. In 1875 Kirchhoff accepted the first chair specifically dedicated to theoretical physics at Berlin.
Gustav Kirchhoff was born in Königsberg, Prussia, the son of Friedrich Kirchhoff, a Lawyer, and Johanna Henriette Wittke. His family were Lutherans in the Evangelical Church of Prussia. He graduated from the Albertus University of Königsberg in 1847 where he attended the mathematico-physical seminar directed by Carl Gustav Jacob Jacobi, Franz Ernst Neumann and Friedrich Julius Richelot. In the same year, he moved to Berlin, where he stayed until he received a professorship at Breslau. Later, in 1857, He married Clara Richelot, the daughter of his mathematics professor Richelot. The couple had five children. Clara died in 1869. He married Luise Brömmel in 1872.
Kirchhoff showed in 1858 that, in thermochemistry, the variation of the heat of a chemical reaction is given by the difference in heat capacity between products and reactants: dΔH / dT = ΔCp. Integration of this equation permits the evaluation of the heat of reaction at one temperature from measurements at another temperature.
In 1862 he was awarded the Rumford Medal for his researches on the fixed lines of the solar spectrum, and on the inversion of the bright lines in the spectra of artificial light.
In 1884 he became foreign member of the Royal Netherlands Academy of Arts and Sciences.
Kirchhoff died in 1887, and was buried in the St Matthäus Kirchhof Cemetery in Schöneberg, Berlin (just a few meters from the graves of the Brothers Grimm). Leopold Kronecker is buried in the same cemetery.