The first image of a black hole

Scientific developments

Karl Schwarzschild solves Einstein's equations

Karl Schwarzschild (1873 – 1916) was a German physicist and astronomer.

Schwarzschild provided the first exact solution to the Einstein field equations of general relativity, for the limited case of a single spherical non-rotating mass, which he accomplished in 1915, the same year that Einstein first introduced general relativity. The Schwarzschild solution, which makes use of Schwarzschild coordinates and the Schwarzschild metric, leads to a derivation of the Schwarzschild radius, which is the size of the event horizon of a non-rotating black hole.

Schwarzschild accomplished this while serving in the German army during World War I. He died the following year from the autoimmune disease pemphigus, which he developed while at the Russian front.

— Wikipedia article on Schwarzschild

The first image of a black hole

On April 10, 2019, the first image ever captured of a black hole was presented to the public. But what were the events that lead to this discovery?