But simple reasoning suggests that there should be an abundance of alien civilizations. Maybe they're all out there, but they are keeping their distance. Welcome to the zoo (hypothesis).
来自MSN1 个月
The Fermi Paradox Zoo HypothesisThe Zoo Hypothesis is a Fermi Paradox solution that assumes extraterrestrial civilizations can't be detected by our SETI efforts because they keep our whole world in an Alien Zoo. Top 10 Best US ...
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