Editing Fermi paradox (section)

=== Willingness to communicate ===
==== Everyone is listening but no one is transmitting ====
Alien civilizations might be technically capable of contacting Earth, but could be only listening instead of transmitting.<ref name=webbwhere>{{cite book| last1=Webb| first1=Stephen| title=If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life| isbn=978-0-387-95501-8|url=https://books.google.com/books?id=Y111CQAAQBAJ&q=fermi+paradox+everybody+listening+nobody+sending&pg=PA148| access-date=June 21, 2015| date=2015| publisher=Springer}}</ref> If all or most civilizations act in the same way, the galaxy could be full of civilizations eager for contact, but everyone is listening and no one is transmitting. This is the so-called ''[[SETI]] Paradox''.<ref>{{cite arXiv |eprint=physics/0611283 |title=The SETI paradox |author=Alexander Zaitsev |date=2006}}</ref>

The only civilization known, humanity, does not [[Active SETI|explicitly transmit]], except for a few small efforts.<ref name=webbwhere /> Even these efforts, and certainly any attempt to expand them, are controversial.<ref>{{cite news |title=Should We Call the Cosmos Seeking ET? Or Is That Risky? |url=https://www.nytimes.com/aponline/2015/02/13/science/ap-us-sci-calling-the-cosmos.html |newspaper=The New York Times |author=The Associated Press |date=February 13, 2015 |access-date=March 1, 2017 |archive-url=https://web.archive.org/web/20150906144552/http://www.nytimes.com/aponline/2015/02/13/science/ap-us-sci-calling-the-cosmos.html |archive-date=September 6, 2015 |url-status=dead }}</ref> It is not even clear humanity would respond to a detected signal—the official policy within the SETI community<ref>{{cite web |url=http://www.seti.org/post-detection.html |title=Protocols for an ETI Signal Detection: Concerning Activities Following the Detection of Extraterrestrial Intelligence |publisher=SETI Institute |access-date=July 12, 2015 |archive-url=https://web.archive.org/web/20150718122415/http://www.seti.org/post-detection.html |archive-date=July 18, 2015 |url-status=dead }}</ref> is that "[no] response to a signal or other evidence of extraterrestrial intelligence should be sent until appropriate international consultations have taken place". However, given the possible impact of any reply,<ref>{{cite journal | last1 = Michaud | first1 = M. | title = Ten decisions that could shake the world | doi = 10.1016/S0265-9646(03)00019-5 | journal = Space Policy | volume = 19 | issue = 2 | pages = 131–950 | year = 2003 | bibcode = 2003SpPol..19..131M }}</ref> it may be very difficult to obtain any consensus on who would speak and what they would say.

==== Communication is dangerous ====
{{see also|Dark forest hypothesis}}
An alien civilization might feel it is too dangerous to communicate, either for humanity or for them. It is argued that when very different civilizations have met on Earth, the results have often been disastrous for one side or the other, and the same may well apply to interstellar contact.<ref>{{cite web |url=https://opinionator.blogs.nytimes.com/2011/10/05/will-the-aliens-be-nice-dont-bet-on-it/ |title=Will the Aliens Be Nice? Don't Bet On It |first=Gary |last=Gutting |date=October 5, 2011 |work=[[The New York Times]] |access-date=May 29, 2020 |archive-url=https://web.archive.org/web/20191001065131/https://opinionator.blogs.nytimes.com/2011/10/05/will-the-aliens-be-nice-dont-bet-on-it/ |archive-date=October 1, 2019 |url-status=live }}</ref> Even contact at a safe distance could lead to infection by computer code<ref>{{cite journal|title=Do potential SETI signals need to be decontaminated? |last=Carrigan |first=Richard A. |journal=Acta Astronautica |volume=58 |issue=2 |pages=112–117|date=2006 |doi=10.1016/j.actaastro.2005.05.004 |bibcode=2006AcAau..58..112C }}</ref> or even ideas themselves.<ref>{{cite journal| last=Marsden| first=P.| title=Memetics and social contagion: Two sides of the same coin| journal=Journal of Memetics-Evolutionary Models of Information Transmission| date=1998| volume=2| issue=2| pages=171–185| url=http://cfpm.org/jom-emit/1998/vol2/marsden_p.html| access-date=October 20, 2011| archive-url=https://web.archive.org/web/20111012004902/http://cfpm.org/jom-emit/1998/vol2/marsden_p.html| archive-date=October 12, 2011| url-status=live}}</ref> Perhaps prudent civilizations actively hide not only from Earth but from everyone, out of [[#It is the nature of intelligent life to destroy others|fear of other civilizations]].<ref name="HawkingFearTheologyAndScience">{{cite journal |last1=A. Vakoch |first1=Douglas |title=Hawking's fear of an alien invasion may explain the Fermi Paradox |journal=Theology and Science |date=3 April 2017 |volume=15 |issue=2 |pages=134–138 |doi=10.1080/14746700.2017.1299380 |s2cid=219627161 |url=https://www.tandfonline.com/doi/pdf/10.1080/14746700.2017.1299380 |access-date=18 October 2022}}</ref>

Perhaps the Fermi paradox itself—or the alien equivalent of it—is the reason for any civilization to avoid contact with other civilizations, even if no other obstacles existed. From any one civilization's point of view, it would be unlikely for them to be the first ones to make first contact. According to this reasoning, it is likely that previous civilizations faced fatal problems upon first contact and doing so should be avoided. So perhaps every civilization keeps quiet because of the possibility that there is a real reason for others to do so.<ref name="Brin" />

In 1987, science fiction author [[Greg Bear]] explored this concept in his novel ''[[The Forge of God]]''.<ref>{{cite news |last1=Cramer |first1=John |title=Self-Reproducing Machines From Another Planet : THE FORGE OF GOD by Greg Bear |url=https://www.latimes.com/archives/la-xpm-1987-09-20-bk-8862-story.html |work=Los Angeles Times |date=1987}}</ref> In ''The Forge of God'', humanity is likened to a baby crying in a hostile forest: "There once was an infant lost in the woods, crying its heart out, wondering why no one answered, drawing down the wolves." One of the characters explains, "We've been sitting in our tree chirping like foolish birds for over a century now, wondering why no other birds answered. The galactic skies are full of hawks, that's why. Planetisms that don't know enough to keep quiet, get eaten."<ref>{{Cite web |title=the_dark_forest |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/the_dark_forest/ |access-date=2024-03-25 |website=warwick.ac.uk}}</ref>

In [[Liu Cixin]]'s 2008 novel ''[[The Dark Forest]]'', the author proposes a literary explanation for the Fermi paradox in which many multiple alien civilizations exist, but are both silent and paranoid, destroying any nascent lifeforms loud enough to make themselves known.<ref name="ChinaFileCixinLiu">{{cite news |author=Kun Kun |others=Translated by Lucy Johnston |title=But Some of Us Are Looking at the Stars |url=https://www.chinafile.com/reporting-opinion/culture/some-us-are-looking-stars |access-date=18 October 2022 |work=ChinaFile |date=4 June 2012 |language=en}}</ref> This is because any other intelligent life may represent a future threat. As a result, Liu's fictional universe contains a plethora of quiet civilizations which do not reveal themselves, as in a "dark forest"...filled with "armed hunter(s) stalking through the trees like a ghost".<ref>{{cite book |last1=Liu |first1=Cixin |title=The dark forest |date=2015 |location=New York |isbn=9780765377081 |page=484 |edition=First}}</ref><ref name="Dark Forest Answer to Star Wars Optimism">{{Cite web |url=https://www.discovermagazine.com/the-sciences/chinas-dark-forest-answer-to-star-wars-optimism |title=China's 'Dark Forest' Answer to 'Star Wars' Optimism |work=Discover Magazine |first=Jeremy |last=Hsu |date=October 31, 2015}}</ref><ref name="Technology's dark forest">{{Cite web |url=https://techcrunch.com/2019/01/20/technologys-dark-forest/ |title=Technology's dark forest |work=TechCrunch |first=Jon |last=Evans |date=January 20, 2019}}</ref> This idea has come to be known as the [[dark forest hypothesis]].<ref name="UnivTodayDarkForest">{{cite news |last1=Williams |first1=Matt |title=Beyond "Fermi's Paradox" XVI: What is the "Dark Forest" Hypothesis? |url=https://www.universetoday.com/149410/beyond-fermis-paradox-xvi-what-is-the-dark-forest-hypothesis/ |access-date=18 October 2022 |work=Universe Today |date=7 January 2021}}</ref><ref name="NHPR">{{cite news |last1=Paradis |first1=Justine |title=Outside/In[box]: What is the Dark Forest Theory? |url=https://www.nhpr.org/environment/2022-02-18/what-is-the-dark-forest-theory-outside-in |access-date=18 October 2022 |work=New Hampshire Public Radio |date=18 February 2022 |language=en}}</ref><ref>{{cite news |last1=Kevra |first1=Derek |first2=Maurielle|last2=Lue|display-authors=etal|title=Dark Forest theory: should we try to contact aliens? |url=https://www.fox2detroit.com/news/dark-forest-theory-should-we-try-to-contact-aliens |access-date=18 October 2022 |work=FOX 2 Detroit |date=11 October 2022}}</ref>

==== Earth is deliberately being avoided ====
{{main|Zoo hypothesis}}
The [[zoo hypothesis]] states that intelligent extraterrestrial life exists and does not contact life on Earth to allow for its natural evolution and development.<ref name=":1">{{cite journal| last1=Ball| first1=J| title=The zoo hypothesis| journal=Icarus| volume=19|issue=3|pages=347–349|date=1973| doi=10.1016/0019-1035(73)90111-5| bibcode=1973Icar...19..347B}}</ref> A variation on the zoo hypothesis is the laboratory hypothesis, where humanity has been or is being subject to experiments,<ref name=":1" /><ref name=":0" /> with Earth or the Solar System effectively serving as a laboratory. The zoo hypothesis may break down under the [[uniformity of motive]] flaw: all it takes is a single culture or civilization to decide to act contrary to the imperative within humanity's range of detection for it to be abrogated, and the probability of such a violation of hegemony increases with the number of civilizations,<ref name=cr /><ref>{{Cite journal|last=Forgan|first=Duncan H.|date=2011-06-08|title=Spatio-temporal constraints on the zoo hypothesis, and the breakdown of total hegemony|journal=International Journal of Astrobiology|volume=10|issue=4|pages=341–347|doi=10.1017/s147355041100019x|arxiv=1105.2497|bibcode=2011IJAsB..10..341F|s2cid=118431252|issn=1473-5504}}</ref> tending not towards a "Galactic Club" with a unified foreign policy with regard to life on Earth but multiple "Galactic Cliques".<ref>{{Cite journal|last=Forgan|first=Duncan H.|date=2016-11-28|title=The Galactic Club or Galactic Cliques? Exploring the limits of interstellar hegemony and the Zoo Hypothesis|journal=International Journal of Astrobiology|volume=16|issue=4|pages=349–354|doi=10.1017/s1473550416000392|arxiv=1608.08770 |hdl=10023/10869|s2cid=59041278|issn=1473-5504|hdl-access=free}}</ref> However, if [[artificial superintelligence]]s dominate galactic life, and if it is true that such intelligences tend towards merged hegemonic behavior, then this would address the uniformity of motive flaw by dissuading rogue behavior.<ref>{{Cite journal |last=Visscher |first=Alex De |date=2020 |title=Artificial versus biological intelligence in the Cosmos: clues from a stochastic analysis of the Drake equation |url=https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/abs/artificial-versus-biological-intelligence-in-the-cosmos-clues-from-a-stochastic-analysis-of-the-drake-equation/7BC4932CD94887E338B2DA55488DE8C6 |journal=International Journal of Astrobiology |language=en |volume=19 |issue=5 |pages=353–359 |doi=10.1017/S1473550420000129 |arxiv=2001.11644 |bibcode=2020IJAsB..19..353D |s2cid=211003646 |issn=1473-5504}}</ref>

Analysis of the inter-arrival times between civilizations in the galaxy based on common astrobiological assumptions suggests that the initial civilization would have a commanding lead over the later arrivals. As such, it may have established what has been termed the ''zoo hypothesis'' through force or as a galactic or universal norm and the resultant "paradox" by a cultural [[founder effect]] with or without the continued activity of the founder.<ref>{{cite journal |last1=Hair |first1=Thomas W. |title=Temporal dispersion of the emergence of intelligence: an inter-arrival time analysis |journal=International Journal of Astrobiology |date=February 25, 2011 |volume=10 |issue=2 |pages=131–135 |doi=10.1017/S1473550411000024|bibcode=2011IJAsB..10..131H |s2cid=53681377 }}</ref> Some colonization scenarios predict spherical expansion across star systems, with continued expansion coming from the systems just previously settled. It has been suggested that this would cause a strong [[natural selection|selection]] process among the colonization front favoring cultural or biological [[adaptation]]s to living in starships or space habitats. As a result, they may forgo living on planets.<ref name="David Brin, 1983, abandonment of planet-dwelling">"The Great Silence: the Controversy Concerning Extraterrestrial Intelligent Life" (15-page paper), ''Quarterly J. Royal Astron. Soc.,'' David Brin, 1983, [http://adsbit.harvard.edu//full/1983QJRAS..24..283B/0000300.000.html p. 300 " ... abandonment of planet-dwelling ... "] {{Webarchive|url=https://web.archive.org/web/20190406165950/http://adsbit.harvard.edu//full/1983QJRAS..24..283B/0000300.000.html|date=April 6, 2019}}.</ref> This may result in the destruction of terrestrial planets in these systems for use as building materials, thus preventing the development of life on those worlds. Or, they may have an ethic of protection for "nursery worlds", and protect them.<ref name="David Brin, 1983, abandonment of planet-dwelling" />

It is possible that a civilization advanced enough to travel between solar systems could be actively visiting or observing Earth while remaining undetected or unrecognized.<ref>{{cite journal |title=What Role Will Extraterrestrials Play in Humanity's Future? |author=Tough, Allen |journal=Journal of the British Interplanetary Society |volume=39 |issue=11 |pages=492–498 |year=1986 |url=http://ww.w.ieti.org/articles/future.pdf |bibcode=1986JBIS...39..491T |access-date=June 27, 2015 |archive-url=https://web.archive.org/web/20150630051853/http://ww.w.ieti.org/articles/future.pdf |archive-date=June 30, 2015 |url-status=live }}</ref> Following this logic, and building on arguments that other proposed solutions to the Fermi paradox may be implausible, [[Ian Crawford (astrobiologist)|Ian Crawford]] and [[Dirk Schulze-Makuch]]<ref>{{cite journal|last1=Crawford|first1= Ian|last2=Schulze-Makuch|first2=Dirk|date=2024 |title=Is the apparent absence of extraterrestrial technological civilisations down to the zoo hypothesis or nothing?|url=https://www.nature.com/articles/s41550-023-02134-2|journal=Nature Astronomy|volume= 8|issue= 1|pages=44–49|doi= 10.1038/s41550-023-02134-2|bibcode=2024NatAs...8...44C }}</ref> have argued that technological civilisations are either very rare in the Galaxy or are deliberately hiding from us.

==== Earth is deliberately being isolated ====
{{Main|Planetarium hypothesis}}
A related idea to the zoo hypothesis is that, beyond a certain distance, the perceived universe is a [[simulated reality]]. The planetarium hypothesis<ref>{{cite journal|author=Baxter, Stephen|date=2001 |title=The Planetarium Hypothesis: A Resolution of the Fermi Paradox| journal=Journal of the British Interplanetary Society| volume= 54|issue=5/6|pages=210–216|bibcode = 2001JBIS...54..210B }}</ref> speculates that beings may have created this simulation so that the universe appears to be empty of other life.