UFOs are a product of a massive conspiracy unrelated to non-human entities
Aliens
EY's mind changes such that a boring explanation is worldview-shattering
EY suffers severe mental degeneration leading to delusions
Eliezer knows aliens are real and will be disclosed soon. He's rallying people to dump money into a bet he is secretly betting against to teach them about the fallacy of appeal to authority.
Simulation Hypothesis
UFOs are time travelers
Holographic Principle
UFOs are angels
UFOs are psychic manifestations
Other
Demons (as in a traditional Abrahamic religion)
Ultraterrestrials (home-grown, advanced non-human civs, hidden from us)
