Dark forest hypothesis
The dark forest hypothesis is the idea that extraterrestrial civilizations may exist in abundance across the universe, but remain silent and hidden out of fear that revealing themselves would lead to destruction by a more technologically advanced and hostile civilization. It is one of several proposed explanations of the Fermi paradox, which contrasts the apparently high probability of extraterrestrial life with the lack of evidence for it. The hypothesis derives its name from Liu Cixin's 2008 novel The Dark Forest although similar concepts predate the work.