Fermi's Paradox: Hypotheses, Optimism, and the Quest for Extraterrestrial Contact
To the point
People explore why no intelligent aliens have been detected despite many stars and habitable planets, summarizing ideas that life might be rare or short‑lived, civilizations hide or are dangerous, self‑replicating probes could spread, and life could be common with slow interstellar travel, all seen through both science and science fiction.