Karl Schwarzschild was born on October 9th, 1873, in Frankfurt am Main, Germany to Henrietta Sabel and Moses Martin Schwarzschild. Karl was the oldest of six children, having 4 brothers and 1 sister. Because of his Jewish ethnicity, he attended a Jewish primary school in Frankfurt until he was 11, and later entered the gymnasium there. It was during that period, that he developed an interest for telescopes which later lead to a love for astronomy. He would save his money to buy the materials needed to construct a telescope. Luckily, his Karl’s father was friends with Professor J, Epstein, who was a well known professor at the Philanthropin Academy, and he even had his own private observatory. It was because of the excellent relationship between the two that Karl had with Epstein that he mastered celestial mechanics by the age of 16. It was because to his understanding, that he wrote two papers on the orbits of double stars while still at the gymnasium. Schwarzschild later studied at the University of Strasbourg, and later at the University of Munich where he obtained his doctorate.
The next few years were spent studying science and the many aspects of space. He worked on ways to determine the apparent brightness of stars using photographic plates, measuring stellar magnitudes, radiation pressure of the sun, what the tails of comets were made of, and the transport of energy through a star by radiation. Although his contributions were not very well known, every discovery is vital when it comes to astronomy.
One of his most famous and well known contribution to science was something called the Gravitational Radius, or the Schwarzschild radius. This is a characteristic radius associated with every mass. This “rule” states that if any spherical mass were to change and to acquire that radius, no known force could prevent it from collapsing into gravitational singularity. This gravitational singularity is also known as a black hole. Schwarzschild obtained this solution just a few months after Einstein discovered the theory of general relativity. The equation for this radius is rs =2Gm/c2. rs would be the Schwarzschild radius, G would be the gravitational constant, m is the mass of the gravitating object, and c is the speed of light. Although this equation proved the existence of black holes, their existence was still debated for decades. The surface at the Schwarzschild radius acts as an event horizon. He stated his discoveries in a paper written in Russia. He was the first to give exact solutions to Einstein’s equations of relativity. Einstein later stated: I had not expected that one could formulate the exact solution of the problem in such a simple way. Karl Schwarzschild was a very important contributor to the advancement of astronomy, and proved the existence of black holes.