Black holes are among the most paradoxical objects ever conceived by humans. They swallow everything that crosses their path and do not even let the light escape from their insides. But instead of constantly growing, they can also become smaller once more over time, until they even disappear once more at some point. This is reminiscent of a joke by cabaret artist Alf Pojer, who warns of the dangers of population growth: It creates more and more people until at some point there aren’t any more.