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%% Please note: this is a Useful Notes page, not a trope. Examples should be limited to works that explicitly discuss or reference the paradox itself. Examples which merely provide a particular solution should be listed on one of the trope pages; either AbsentAliens or InivisibleAliens.
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The Fermi Paradox is an observation/question by physicist Enrico Fermi: The universe is very old. Life (from a scientific viewpoint) seems to be relatively simple--simple enough that, given the unimaginable size of the universe, there should be millions of planets with life scattered out there. And even without Faster-than-Light Travel, an intelligent spacefaring species should be able to spread across the galaxy in a relatively short amount of time. So ''where are all the aliens?''

We should be able to see all kinds of signs for intelligent alien life when we look at the stars, or possibly even evidence of alien life visiting Earth. But we don't.

There are numerous proposed solutions to this question, which break down into two broad categories:

* AbsentAliens is [[OccamsRazor the simple solution]], and makes for a fairly straightforward story: the entire universe is essentially uninhabited, and out there for us to settle freely.

* InvisibleAliens is more tricky, as there may be all kinds of reasons we might not see the aliens that are out there. Even if life is common, ''intelligent'' life might be rare for any of a number of reasons. And even if intelligent life is common, it might be hiding, or it might not last very long. If they're bizarre StarfishAliens, we may simply not recognize what we're looking at. If they're SufficientlyAdvancedAliens, we may not even have discovered the technologies required to detect them. And if they're more than sufficiently advanced, their intelligence might have led to some sort of [[AscendedToAHigherPlaneOfExistence transcendence]] that we can't detect, even in theory. Alternatively, they may be perfectly visible already, but TheMenInBlack are making sure the general public doesn't realize it.

Related to the paradox is the [[http://en.wikipedia.org/wiki/Drake_equation Drake equation]], one attempt to quantify the elements required to actually discover other intelligent life forms out there -- unfortunately, most of its terms are unknown, and can never ''be'' known for sure until after we resolve the Fermi Paradox one way or the other: either by finally contacting an alien civilization, or by exploring enough of the universe to say convincingly that they don't exist.

TheOtherWiki has [[http://en.wikipedia.org/wiki/Fermi%27s_paradox more details]].
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!! Works that mention or discuss the paradox:
* ''WebVideo/ExtraCredits'' devotes [[MultiPartEpisode a two-parter]] to this subject and the Drake Equation. Available [[http://www.penny-arcade.com/patv/episode/funding-xcom-part-1 here]] and [[http://www.penny-arcade.com/patv/episode/funding-xcom-part-2 here.]]
* StephenBaxter's three ''Manifold'' novels investigate three different solutions (using the same characters in each novel):
** ''Literature/ManifoldTime'' assumes AbsentAliens.
** ''Literature/ManifoldSpace'' assumes intelligent races don't last long.
** ''Literature/ManifoldOrigin'' assumes each universe in a multiverse has its own unique intelligent race.
* The band Music/TubRing has albums named ''Fermi Paradox'' and ''Drake's Equation''.
* One strip of ''Webcomic/{{xkcd}}'' suggests that the solution to the paradox is that [[http://xkcd.com/962/ fun trumps survival]].
** [[http://xkcd.com/1377/ Another]] offers an alternative solution, [[spoiler: they're all hiding]]
* A favorite subject of Creator/DavidBrin's:
** [[http://www.davidbrin.com/xenology2.htm Xenology: The Science of Asking Who's Out There]] is an essay on the subject.
** ''Literature/{{Existence}}'' discusses the paradox at length, especially in the chapter headers.
* "The Fermi Paradox is Our Business Model" is the name of a short story by Charlie Jane Anders.
* Discussed by an astronomer and a possible answer provided in ''VariableStar''. [[spoiler: As a GenerationShip leaves Earth, the astronomer on the ship sees something odd about the sun. A quarter of the way through their trip, the sun explodes, destroying the entire solar system. The inhabitants of the ship conclude that this was done on purpose by an alien race, resolving the paradox AbusivePrecursors style.]]
* [[{{Comicbook/FantasticFour}} The Fantastic Four]]: OmnidisciplinaryScientist Reed Richards researched this problem once. The answer? [[spoiler: PlanetEater]] {{Galactus}}.
* ''MoreInformationThanYouRequire'' proposes a solution: that the aliens are merely very far away. Possibly even... ''on other planets''. It's also implied that [[BeethovenWasAnAlienSpy Fermi himself was an alien.]]
* ''Series/MassEffect'' Zig zags this. An EldritchAbomination species called the Reapers eliminates all space faring species once every 50,000 years but with the space transportation technology available, any number of species humanity does encounter could have visited us prior to our space age. In fact they did visit a pre-space age species and give them space travel so that they could help in a war, which led to disastrous results. So the reason we aren't visited is a combination of implied AlienNonInterferenceClause and EldritchAbomination.
* In ''Webcomic/AMiracleOfScience'' Mars re-established contact with the rest of humanity after going out into the universe and finding no aliens, [[spoiler: they were all dead.]]
* GeorgeCarlin half-jokingly suggested that we haven't discovered aliens because they know exactly how bad we are as a species and are actively avoiding us.
** ''ComicStrip/CalvinAndHobbes'' suggested the same thing, only on a more somber note.
-->'''Calvin:''' "I think the surest sign of intelligent life in the universe is that none of it has ever tried to contact us."
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