Enrico Fermi
Fermi wrote a paper "On the Origin of Cosmic Radiation" in which he proposed that cosmic rays arose through material being accelerated by magnetic fields in interstellar space, which led to a difference of opinion with Teller. Fermi examined the issues surrounding magnetic fields in the arms of a spiral galaxy. He mused about what is now referred to as the "Fermi paradox": the contradiction between the presumed probability of the existence of extraterrestrial life and the fact that contact has not been made.
Toward the end of his life, Fermi questioned his faith in society at large to make wise choices about nuclear technology. He said:
The Dark Forest
Back on Earth, Luo Ji and another contemporary, Da Shi, discover that star 187J3X1 has been destroyed, causing the UN to restore Luo Ji's Wallfacer status. Luo Ji explains to Da Shi the implications he derived from Ye Wenjie's two axioms of cosmic civilization: 1. Each civilization's goal is survival, and 2. Resources are finite. Like hunters in a "dark forest", a civilization can never be certain of an alien civilization's true intentions. The extreme distance between stars creates an insurmountable "chain of suspicion" where any two civilizations cannot communicate well enough to relieve mistrust, making conflict inevitable. Therefore, it is in every civilization's best interest to preemptively strike and destroy any developing civilization before it can become a threat, but without revealing their own location, thus explaining the Fermi paradox.