According to the novel The Coming Race (1871) by Vril derived their Vril Energy from the Black Sun, a ball of Prima Materia.” Some suspect that the Nazis used this power source for the UFOs.
Book:
Black Sun: Aryan Cults, Esoteric Nazism and the Politics of Identity by Nicholas Goodrick-Clarke New York University Press, 2002, ISBN 0-8147-3124-4
also:
Sol Nigredo, the part of the alchemical process where the materials used to make the Philosopher’s Stone are allowed to ferment in darkness.
also:
Revelations 6:12
also:
Black Sun is the elite bar in the virtual world of the novel Snow Crash.