Karl Schwarzschild

Karl Schwarzschild was born on 9 October 1873 in Frankfurt am Main, the eldest of six boys and one girl, to Jewish parents. His father was active in the business community of the city, and the family had ancestors in Frankfurt from the sixteenth century onwards. The family owned two fabric stores in Frankfurt. His brother Alfred became a painter. The young Schwarzschild attended a Jewish primary school until 11 years of age and then the 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. He proved to be a child prodigy, having two papers on binary orbits (celestial mechanics) published before the age of sixteen. After graduation in 1890, he attended the University of Strasbourg to study astronomy. After two years he transferred to the Ludwig-Maximilians-Universität München, 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 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, 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 of Potsdam. This was then the most prestigious post available for an astronomer in Germany. , 1910 From 1912, Schwarzschild was a member of the Prussian Academy of Sciences. Work on general relativity and death At the outbreak of World War I in 1914, Schwarzschild volunteered for service in the German army despite being over 40 years old. He served on both the western and eastern fronts, specifically helping with ballistic calculations and rising to the rank of second lieutenant in the artillery. Nevertheless, he managed to write three important papers, two on the theory of relativity and one on 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. He also identified the Schwarzschild radius, at which a star will form what is now known as a black hole, though he wrongly believed this finding to be a mathematical curiosity that had no practical relevance. Twenty-three years after Schwarzschild's death, J. Robert Oppenheimer and Hartland Snyder correctly predicted the existence of black holes in their Oppenheimer–Snyder model, though they did not draw directly on Schwarzschild's work. Schwarzschild died of immune complications related to his illness on 11 May 1916, at the age of 42. • Martin Schwarzschild (1912–1997) became a professor of astronomy at Princeton University, and was the first astronomer to lift a telescope into the stratosphere by balloon. • Alfred Schwarzschild (1914–1944) remained in Nazi Germany and was murdered during the Holocaust. ==Work==