The finale of the first season, (S1E10), centers heavily on the Bootstrap Paradox .
The episode concludes with the revelation that the loop is seemingly unbreakable, as characters receive letters and objects from their future selves that have no clear origin point (a classic causal loop). 3. Revisionist History (Podcast)
Paradox was a 1950s scientist accidentally sucked into a rift in time and space, where he spent eons learning everything about the universe before gaining the ability to travel through time at will.
It is the contradiction between the high probability of extraterrestrial life and the complete lack of evidence for or contact with such civilizations.