The Fermi paradox
The Fermi paradox is the seeming inconsistency between the lack of evidence of extraterrestrial civilizations and the apparently high likelihood of their existence. Given that there are an estimated 200–400 billion stars in the Milky Way and 70 sextillion in the observable universe, it seems probable that intelligent life should exist elsewhere. Yet there is no convincing evidence that alien civilizations have visited Earth or left detectable traces. This paradox matters because it challenges our assumptions about life in the universe. Are intelligent beings extremely rare? Do civilizations die out quickly? Or do they exist but remain undetected? The paradox, famously posed by physicist Enrico Fermi with the question "But where is everybody?" in 1950, continues to spark scientific debate about the nature and frequency of life beyond Earth.
Sources
- en.wikipedia.org: “The Fermi paradox is the seeming inconsistency between the lack of evidence of extraterrestrial civilizations and the apparently high likelihood of their existence.”
- en.wikipedia.org: “there are an estimated 200–400 billion stars in the Milky Way (2–4 × 1011) and 70 sextillion (7×1022) in the observable universe.”
- en.wikipedia.org: “However, there is no convincing evidence that this has happened.”
- en.wikipedia.org: “Enrico Fermi was a Nobel Prize-winning physicist who was known to pose simple but seemingly unanswerable questions”