Caption: Karl Schwarzschild (1873--1916) at work.

Features:

1. Schwarzschild is the discoverer of the famous Schwarzschild solution in general relativity.

2. The Schwarzschild solution is one of the few top-level (i.e., general and important) exact analytic solutions in general relativity. How many such solutions exist depends on one's definition of "exact analytic solution" and what one judges to be top-level. By one expert's count, there are only 6 top-level ones (see McCallum, 2013, Exact solutions of Einstein's equations) and he counts the Schwarzschild solution only as a special case of the Kerr solution.

   As far as yours truly knows, Albert Einstein (1879--1955) himself only ever found only one exact analytic solution (the Einstein universe) and it is only a special case of one of the 6 general solutions: i.e., the Friedmann-Lemaitre-Robertson-Walker (FLRW) solution.

   An exact analytic solution is a solution which can be expressed as formulae you can just write down and has NO approximations

3. The Schwarzschild solution gives the curvature of space (and therefore gravitational field) for a spherically symmetric mass distribution isolated in physical space from everything else.

4. The Schwarzschild solution predicts the existence of black holes: to be precise, Schwarzschild black holes, the simplest kind of ideal black hole.

   Note Schwarzschild did NOT use the term black hole which was coined in the 1960s. For the coinage, see Astronomer file: ann_ewing.html.

5. Schwarzschild himself thought the black hole feature of the Schwarzschild solution was physically meaningless: i.e., it was pushing general relativity beyond its realm of validity.

   However, Schwarzschild did NOT have a lot of time to think about the meaning of black holes. He found his eponymous exact analytic solution while serving in the Imperial German Army in 1915 at the Russian front. He was soon invalided out of active duty by a rare autoimmune disease and died in 1916. Schwarzschild was such a brilliant general relativist that it plausible to think that he would have anticipated some of the general-relativity results of others if he had lived longer: e.g., some of the early cosmological models that fall into the class of the Friedmann-Lemaitre-Robertson-Walker (FLRW) models.