The zoo hypothesis
speculates on the assumed behavior and existence of technologically advanced
extraterrestrial life
Extraterrestrial life, or alien life (colloquially, aliens), is life that originates from another world rather than on Earth. No extraterrestrial life has yet been scientifically conclusively detected. Such life might range from simple forms ...
and the reasons they refrain from contacting
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
. It is one of many theoretical explanations for the
Fermi paradox
The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. Those affirming the paradox generally conclude that if the conditions required ...
. The hypothesis states that extraterrestrial life intentionally avoids communication with Earth to allow for natural
evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
and
sociocultural development, and avoiding
interplanetary contamination
Interplanetary contamination refers to biological contamination of a planetary body by a space probe or spacecraft, either deliberate or unintentional.
There are two types of interplanetary contamination:
*''Forward contamination'' is the transf ...
, similar to people observing animals at a zoo. The hypothesis seeks to explain the apparent absence of extraterrestrial life despite its generally accepted plausibility and hence the reasonable expectation of its existence.
Extraterrestrial life forms might, for example, choose to allow contact once the human species has passed certain technological, political, and/or ethical standards. Alternatively, they may withhold contact until humans force contact upon them, possibly by sending a
spacecraft
A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...
to an extraterrestrial-inhabited planet. In this regard, reluctance to initiate contact could reflect a sensible desire to minimize risk. An extraterrestrial society with advanced remote-sensing technologies may conclude that direct contact with neighbors confers added risks to itself without an added benefit. A variant on the zoo hypothesis suggested by former MIT Haystack Observatory scientist John Allen Ball is the "laboratory" hypothesis, in which humanity is being subjected to experiments, with Earth serving as a giant laboratory.
Ball describes this hypothesis as "morbid" and "grotesque",
simultaneously overlooking the possibility that such experiments may be
altruistic
Altruism is the concern for the well-being of others, independently of personal benefit or reciprocity.
The word ''altruism'' was popularised (and possibly coined) by the French philosopher Auguste Comte in French, as , for an antonym of egoi ...
, i.e., designed to accelerate the pace of
civilization
A civilization (also spelled civilisation in British English) is any complex society characterized by the development of state (polity), the state, social stratification, urban area, urbanization, and symbolic systems of communication beyon ...
to overcome
a tendency for intelligent life to destroy itself, until a species is sufficiently developed to establish contact.
Assumptions
The zoo hypothesis assumes, first, that whenever the conditions are such that life can exist and evolve, it will, and secondly, there are many places where life can exist and a large number of extraterrestrial cultures in existence.
[ It also assumes that these extraterrestrials have great reverence for independent, natural evolution and development. In particular, assuming that intelligence is a physical process that acts to maximize the diversity of a system's accessible futures, a fundamental motivation for the zoo hypothesis would be that premature contact would "unintelligently" reduce the overall diversity of paths the universe itself could take.
These ideas are perhaps most plausible if there is a relatively universal cultural or legal policy among a plurality of extraterrestrial civilizations necessitating isolation with respect to civilizations at Earth-like stages of development. In a universe without a ]hegemonic
Hegemony (, , ) is the political, economic, and military predominance of one state over other states, either regional or global.
In Ancient Greece (ca. 8th BC – AD 6th c.), hegemony denoted the politico-military dominance of the ''hegemon'' ...
power, random single civilizations with independent principles would make contact. This makes a crowded universe with clearly defined rules seem more plausible.
If there is a plurality of extraterrestrial cultures, however, this theory may break down under the uniformity of motive concept because it would take just a single extraterrestrial civilization, or simply a small group within any given civilisation, to decide to act contrary to the imperative within human range of detection for it to be undone, and the probability of such a violation of hegemony increases with the number of civilizations. This idea, however, becomes more plausible if all civilizations tend to evolve similar cultural standards and values with regard to contact much like convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...
on Earth has independently evolved eyes on numerous occasions, or all civilizations follow the lead of some particularly distinguished civilization, such as the first civilization among them.
In this hypothesis, the problem of universal ethical homogeneity is solved because the acquisition of a persistent advanced level of civilization requires overcoming many problems, such as self-destruction, war, overpopulation, pollution, and scarcity. Managing to solve these problems could guide a civilization to adopt a responsible and wise behavior, otherwise they would disappear (involving other solutions to the Fermi paradox). In the zoo hypothesis, no contact would be possible until humanity had acquired a certain level of civilization and maturity (responsibility and wisdom), otherwise it would become a potential threat.
One estimate for when humanity might be able to test the zoo hypothesis, essentially by eliminating ways technological extraterrestrials within the galaxy may be able to hide, is some time within the next half century.
Fermi paradox
A modified zoo hypothesis is a possible solution to the Fermi paradox. The time between the emergence of the first civilization within the Milky Way
The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...
and all subsequent civilizations could be enormous. Monte Carlo simulation
Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be det ...
shows the first few inter-arrival times between emergent civilizations would be similar in length to geologic epochs on Earth. The zoo hypothesis assumes a civilization may have a ten-million, one-hundred-million, or half-billion-year head start on humanity, i.e., it may have the capability to completely negate our best attempts to detect it.
The zoo hypothesis relies in part on applying the concept of hegemonic power to the Fermi paradox. Even if a first hegemonic non-interventionist
Non-interventionism or non-intervention is commonly understood as "a foreign policy of political or military non-involvement in foreign relations or in other countries' internal affairs". This is based on the grounds that a state should not inter ...
grand civilization ( first civilization) is long gone, their initial legacy could persist in the form of a passed-down tradition, or perhaps in an artificial lifeform ( artificial superintelligence) dedicated to a non-interventionist hegemonic goal without the risk of death. Thus, the hegemonic power does not even have to be the first civilization, but simply the first to spread its non-interventionist doctrine and control over a large volume of the galaxy. If just one civilization acquired hegemony in the distant past, it could form an unbroken chain of taboo against rapacious colonization in favour of non-interference in any civilizations that follow. The uniformity of motive concept previously mentioned would become moot in such a situation. The main problem would be how a galaxy-wide civilization would block Earth from receiving all intentional or unintentional communications.
Nonetheless, if the oldest civilization still present in the Milky Way has, for example, a 100-million-year time advantage over the next oldest civilization, then it is conceivable that they could be in the singular position of being able to control, monitor, influence or isolate the emergence of every civilization that follows within their sphere of influence. This is analogous to what happens on Earth within our own civilization on a daily basis, in that everyone born on this planet is born into a pre-existing system of familial associations, customs, traditions and laws that were already long established before our birth and which we have little or no control over.
METI (Messaging Extraterrestrial Intelligence)
Overcoming the zoo hypothesis is one of the goals of METI, an organization created in 2015 to communicate with extraterrestrials, an active form of the search for extraterrestrials (SETI). METI, however, has been criticized for not representing humanity's collective will and for potentially endangering humanity.
Criticism
Some critics of the hypothesis say that only a single dissident group in an extraterrestrial civilization, or alternatively the existence of galactic cliques instead of a unified galactic club, would be enough to break the pact of no contact. To Stephen Webb and others, it seems unlikely, taking humans and human intercivilizational politics as reference, that such prohibition would be in effect for millions of years or at least human existence without a single breach thereof. Others say that the zoo hypothesis, along with its planetarium
A planetarium (: planetariums or planetaria) is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation.
A dominant feature of most planetariums is ...
variation, is highly speculative and more aligned with theological
Theology is the study of religious belief from a religious perspective, with a focus on the nature of divinity. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of an ...
theories. One possible counterargument to the dissident (rogue) group argument is that extraterrestrial artificial superintelligences dominate space, including space occupied by biological intelligences; moreoever, separate artificial superintelligences are assumed to tend towards a network of merged superintelligencies, thereby dissuading rogue behaviour.
Appearance in fiction
The zoo hypothesis is a common theme in science fiction.
1930s
* 1937: In Olaf Stapledon's 1937 novel ''Star Maker
''Star Maker'' is a science fiction novel by British writer Olaf Stapledon, published in 1937. Continuing the theme of the author's previous book, ''Last and First Men'' (1930)—which narrated a history of the human species over two billion ...
'', great care is taken by the Symbiont race to keep its existence hidden from "pre-utopian" primitives, "lest they should lose their independence of mind.” It is only when such worlds become utopian-level space travellers that the Symbionts make contact and bring the young utopia to an equal footing.
1950s
* 1951: Arthur C. Clarke's '' The Sentinel'' (first published in 1951) and its later novel adaptation '' 2001: A Space Odyssey'' (1968) feature a beacon which is activated when the human race discovers it on the moon.
* 1953: In '' Childhood's End'', a novel by Arthur C. Clarke published in 1953, the alien cultures had been observing and registering Earth's evolution and human history for thousands (perhaps millions) of years. At the beginning of the book, when mankind is about to achieve spaceflight
Spaceflight (or space flight) is an application of astronautics to fly objects, usually spacecraft, into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such ...
, the aliens reveal their existence and quickly end the arms race
An arms race occurs when two or more groups compete in military superiority. It consists of a competition between two or more State (polity), states to have superior armed forces, concerning production of weapons, the growth of a military, and ...
, colonialism
Colonialism is the control of another territory, natural resources and people by a foreign group. Colonizers control the political and tribal power of the colonised territory. While frequently an Imperialism, imperialist project, colonialism c ...
, racial segregation
Racial segregation is the separation of people into race (human classification), racial or other Ethnicity, ethnic groups in daily life. Segregation can involve the spatial separation of the races, and mandatory use of different institutions, ...
and the Cold War
The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...
.
1960s
* In ''Star Trek
''Star Trek'' is an American science fiction media franchise created by Gene Roddenberry, which began with the Star Trek: The Original Series, series of the same name and became a worldwide Popular culture, pop-culture Cultural influence of ...
'', the Federation
A federation (also called a federal state) is an entity characterized by a political union, union of partially federated state, self-governing provinces, states, or other regions under a #Federal governments, federal government (federalism) ...
(including humans) has a strict Prime Directive
In the fictional universe of ''Star Trek'', the Prime Directive (also known as "Starfleet General Order 1", and the "non-interference directive") is a guiding principle of Starfleet that prohibits its members from interfering with the natural dev ...
policy of nonintervention with less technologically advanced cultures which the Federation encounters. The threshold of inclusion is the independent technological development of faster-than-light
Faster-than-light (superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light in vacuum (). The special theory of relativity implies that only particles with zero ...
propulsion. In the show's canon, the Vulcan race limited their encounters to observation until Humans made their first warp flight, after which they initiated first contact, indicating the practice predated the Human race's advance of this threshold. Additionally, in the episode " The Chase (TNG)", a message from a first (or early) civilization is discovered, hidden in the DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
of sentient
Sentience is the ability to experience feelings and sensations. It may not necessarily imply higher cognitive functions such as awareness, reasoning, or complex thought processes. Some writers define sentience exclusively as the capacity for ''v ...
species spread across many worlds, something that could only have been fully discovered after a race had become sufficiently advanced.
* In '' Hard to Be a God'' by Arkady and Boris Strugatsky
The brothers Arkady Strugatsky (28 August 1925 – 12 October 1991) and Boris Strugatsky (14 April 1933 – 19 November 2012) were Soviet and Russian science-fiction authors who collaborated through most of their careers. Their notable works in ...
, the (unnamed) medieval-esque planet where the novel takes action is protected by the advanced civilization of Earth, and the observers from Earth present on the planet are forbidden to intervene and make overt contact. One of the major themes of the novel is the ethical dilemma presented by such a stance to the observers.
1980s
* 1986: In ''Speaker for the Dead
''Speaker for the Dead'' is a 1986 science fiction novel by American writer Orson Scott Card, an indirect sequel to the 1985 novel ''Ender's Game''. The book takes place around the year 5270, some 3,000 years after the events in ''Ender's Game ...
'' by Orson Scott Card
Orson Scott Card (born August 24, 1951) is an American writer known best for his science fiction works. , he is the only person to have won a Hugo Award for Best Novel, Hugo Award and a Nebula Award for Best Novel, Nebula Award in List of joint ...
, the human xenobiologists and xenologers, biologists and anthropologists observing alien life are forbidden from giving the native species, the Pequeninos, any technology or information. When one of the xenobiologists is killed in an alien ceremony, they are forbidden to mention it. This happens again until Ender Wiggin, the main character of ''Ender's Game
''Ender's Game'' is a 1985 military science fiction novel by American author Orson Scott Card. Set at an unspecified date in Earth's future, the novel presents an imperiled humankind after two conflicts with an insectoid alien species they ...
'', explains to the Pequeninos that humans cannot partake in the ceremony because it kills them. While this is not exactly an example of the zoo hypothesis, since humanity makes contact, it is very similar and the humans seek to keep the Pequeninos ignorant of technology.
* 1987: In Julian May's 1987 novel '' Intervention'', the five alien races of the Galactic Milieu keep Earth under surveillance, but do not intervene until humans demonstrate mental and ethical maturity through a paranormal prayer of peace.
* 1989: Iain M. Banks' '' The State of the Art'' depicts the Culture
The Culture is a fictional interstellar post-scarcity civilisation or society created by the Scottish writer Iain Banks and features in a number of his space opera novels and works of short fiction, collectively called the ''Culture'' series.
...
secretly visiting Earth and then deciding to leave it uncontacted, watching its development as a control group
In the design of experiments, hypotheses are applied to experimental units in a treatment group.
In comparative experiments, members of a control group receive a standard treatment, a placebo, or no treatment at all. There may be more than one tr ...
, to confirm whether their manipulations of other civilizations are ultimately for the best (the laboratory hypothesis). Other works by Banks depict the Culture (or a Culture equivalent) routinely manipulating less advanced civilizations, including pre-industrial ones (e.g., '' Inversions''), both covertly and overtly, for philosophical or foreign policy purposes.
* 1989: Bill Watterson
William Boyd Watterson II (born July 5, 1958) is an American cartoonist who authored the comic strip ''Calvin and Hobbes''. The strip was syndicated from 1985 to 1995. Watterson concluded ''Calvin and Hobbes'' with a short statement to newspa ...
's ''Calvin and Hobbes
''Calvin and Hobbes'' is a daily American comic strip created by cartoonist Bill Watterson that was Print syndication, syndicated from November 18, 1985, to December 31, 1995. Commonly described as "the last great newspaper comic", ''Calvin a ...
'' comic strip for 8 November 1989 alludes to the possibility of an ethical threshold for first contact (or at least for the prudence of first contact) in Calvin's remark "Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us."
2000s
* 2000: In Robert J. Sawyer's SF novel '' Calculating God'' (2000), Hollus, a scientist from an advanced alien civilization, denies that her government is operating under the prime directive.
* 2003: In ''South Park
''South Park'' is an American animated sitcom created by Trey Parker and Matt Stone, and developed by Brian Graden for Comedy Central. The series revolves around four boysStan Marsh, Kyle Broflovski, Eric Cartman, and Kenny McCormickand the ...
'' inaugural episode of season seven, " Cancelled", aliens refrain from contacting Earth because the planet is the subject and setting of a reality television show. Unlike most variations of the zoo hypothesis where contact is not initiated in order to allow organic socioeconomic, cultural, and technological development, the aliens in this episode refrain from contact for the sole purpose of entertainment. In essence, the aliens treat all of Earth like the titular character in ''The Truman Show
''The Truman Show'' is a 1998 American Psychological film, psychological comedy-drama film written and co-produced by Andrew Niccol, and directed by Peter Weir. The film depicts the story of Truman Burbank (played by Jim Carrey), a man who is un ...
'' in order to maintain the show's integrity.
* 2008: In the video game ''Spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
'', which simulates the evolution and life of species on a fictional galaxy, intelligent species in the "Space Stage" cannot contact those in previous stages, which did not unify their planets, nor develop spaceflight
Spaceflight (or space flight) is an application of astronautics to fly objects, usually spacecraft, into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such ...
yet. However, they are allowed to abduct their citizens/members, to create crop circle
A crop circle, crop formation, or corn circle is a pattern created by flattening a crop, usually a cereal. The term was first coined in the early 1980s. Crop circles have been described as all falling "within the range of the sort of thing ...
s in their terrain and to place in their planets a tool called "monolith
A monolith is a geological feature consisting of a single massive stone or rock, such as some mountains. Erosion usually exposes the geological formations, which are often made of very hard and solid igneous or metamorphic rock. Some monolit ...
", which accelerates their technological evolution.
2010s
* 2012: In the sci-fi
Science fiction (often shortened to sci-fi or abbreviated SF) is a genre of speculative fiction that deals with imaginative and futuristic concepts. These concepts may include information technology and robotics, biological manipulations, space ...
video game ''Star Citizen
''Star Citizen'' is a multiplayer, space trading and combat simulation video game currently under development by Cloud Imperium Games for Windows. An extended retry of unrealized plans for ''Freelancer'' (2003), ''Star Citizen'' is led by dire ...
'', the zoo hypothesis is vaguely referenced in a lore point and is referred to as the Fair Chance Act. In the document, humans are generally forbidden from terraforming
Terraforming or terraformation ("Earth-shaping") is the hypothetical process of deliberately modifying the atmosphere, temperature, surface topography or ecology of a planet, moon, or other body to be similar to the environment of Earth to mak ...
, mining, and inhabiting planets if the world is found to harbor lifeforms capable of developing intelligence. Multiple planetary system
A planetary system is a set of gravity, gravitationally bound non-stellar Astronomical object, bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although ...
s are planned to be implemented as the game's active development continues that will feature planets protected under the Fair Chance Act.
* 2016: In the video game '' Stellaris'', players control an interstellar empire that can encounter less technologically advanced, non-space faring civilizations. Depending on player choices and their empire's organization, they can observe such "pre faster-than-light
Faster-than-light (superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light in vacuum (). The special theory of relativity implies that only particles with zero ...
" planets in a manner similar to the zoo hypothesis, using science stations with missions that can include passive observation, technological enlightenment, covert infiltration and indoctrination
Indoctrination is the process of inculcating (teaching by repeated instruction) a person or people into an ideology, often avoiding critical analysis. It can refer to a general process of socialization. The term often implies forms of brainwas ...
. Players can also discover "pre-sapient" species, which can be uplifted to sentience
Sentience is the ability to experience feelings and sensations. It may not necessarily imply higher cognitive functions such as awareness, reasoning, or complex thought processes. Some writers define sentience exclusively as the capacity for ''v ...
using scientific research projects.
See also
*Uncontacted peoples
Uncontacted peoples are groups of Indigenous peoples living without sustained contact with neighbouring communities and the world community. Groups who decide to remain uncontacted are referred to as indigenous peoples in voluntary isolation. Leg ...
References
{{Portal bar, Biology, Society, Astronomy, Stars, Spaceflight, Outer space, Solar System, Science
Extraterrestrial life
Hypotheses
Fermi paradox
Biological hypotheses
Search for extraterrestrial intelligence