Zoo Hypothesis Research Articles

Is the apparent absence of extraterrestrial technological civilizations down to the zoo hypothesis or nothing?

Is the apparent absence of extraterrestrial technological civilizations down to the zoo hypothesis or nothing?

‘Oumuamua Is Not a Probe Sent to Our Solar System by an Alien Civilization

'Oumuamua, the first known object of extrasolar origin seen to enter our Solar System, has multiple unusual characteristics that, taken together, are very difficult to explain with conventional astronomical entities like asteroids and comets. Consequently, it has been hypothesized that 'Oumuamua is an interstellar probe that was constructed by an alien civilization. We demonstrate that the accomplishments that can be achieved with large space telescopes/interferometers in the alien's planetary system will completely quench any motivation for construction and launch of an 'Oumuamua-like probe. The absence of any such motivation attests that 'Oumuamua is not an alien creation. The existence of large space telescopes has important implications for a range of topics that include interstellar space travel, the Zoo Hypothesis, METI, and UFOs.

The Galactic Club or Galactic Cliques? Exploring the limits of interstellar hegemony and the Zoo Hypothesis

AbstractThe Zoo solution to Fermi's Paradox proposes that extraterrestrial intelligences (ETIs) have agreed to not contact the Earth. The strength of this solution depends on the ability for ETIs to come to agreement, and establish/police treaties as part of a so-called ‘Galactic Club’. These activities are principally limited by the causal connectivity of a civilization to its neighbours at its inception, i.e. whether it comes to prominence being aware of other ETIs and any treaties or agreements in place. If even one civilization is not causally connected to the other members of a treaty, then they are free to operate beyond it and contact the Earth if wished, which makes the Zoo solution ‘soft’. We should therefore consider how likely this scenario is, as this will give us a sense of the Zoo solution's softness, or general validity. We implement a simple toy model of ETIs arising in a Galactic Habitable Zone, and calculate the properties of the groups of culturally connected civilizations established therein. We show that for most choices of civilization parameters, the number of culturally connected groups is >1, meaning that the Galaxy is composed of multiple Galactic Cliques rather than a single Galactic Club. We find in our models for a single Galactic Club to establish interstellar hegemony, the number of civilizations must be relatively large, the mean civilization lifetime must be several millions of years, and the inter-arrival time between civilizations must be a few million years or less.

A direct communication proposal to test the Zoo Hypothesis

Whether we are alone in the universe is one of the greatest mysteries facing humankind. Given the >100 billion stars in our galaxy, many have argued that it is statistically unlikely that life, including intelligent life, has not emerged anywhere else. The lack of any sign of extraterrestrial intelligence, even though on a cosmic timescale extraterrestrial civilizations would have enough time to cross the galaxy, is known as Fermi's Paradox. One possible explanation for Fermi's Paradox is the Zoo Hypothesis which states that one or more extraterrestrial civilizations know of our existence and can reach us, but have chosen not to disturb us or even make their existence known to us. I propose here a proactive test of the Zoo Hypothesis. Specifically, I propose to send a message using television and radio channels to any extraterrestrial civilization(s) that might be listening and inviting them to respond. Even though I accept this is unlikely to be successful in the sense of resulting in a response from extraterrestrial intelligences, the possibility that extraterrestrial civilizations are monitoring us cannot be dismissed and my proposal is consistent with current scientific knowledge. Besides, issuing an invitation is technically feasible, cheap and safe, and few would deny the profound importance of establishing contact with one or more extraterrestrial intelligences. A website has been set up (http://active-seti.info) to encourage discussion of this proposal and for drafting the invitation message.

The transcension hypothesis: Sufficiently advanced civilizations invariably leave our universe, and implications for METI and SETI

The emerging science of evolutionary developmental (“evo devo”) biology can aid us in thinking about our universe as both an evolutionary system, where most processes are unpredictable and creative, and a developmental system, where a special few processes are predictable and constrained to produce far-future-specific emergent order, just as we see in the common developmental processes in two stars of an identical population type, or in two genetically identical twins in biology. The transcension hypothesis proposes that a universal process of evolutionary development guides all sufficiently advanced civilizations into what may be called "inner space," a computationally optimal domain of increasingly dense, productive, miniaturized, and efficient scales of space, time, energy, and matter, and eventually, to a black-hole-like destination. Transcension as a developmental destiny might also contribute to the solution to the Fermi paradox, the question of why we have not seen evidence of or received beacons from intelligent civilizations. A few potential evolutionary, developmental, and information theoretic reasons, mechanisms, and models for constrained transcension of advanced intelligence are briefly considered. In particular, we introduce arguments that black holes may be a developmental destiny and standard attractor for all higher intelligence, as they appear to some to be ideal computing, learning, forward time travel, energy harvesting, civilization merger, natural selection, and universe replication devices. In the transcension hypothesis, simpler civilizations that succeed in resisting transcension by staying in outer (normal) space would be developmental failures, which are statistically very rare late in the life cycle of any biological developing system. If transcension is a developmental process, we may expect brief broadcasts or subtle forms of galactic engineering to occur in small portions of a few galaxies, the handiwork of young and immature civilizations, but constrained transcension should be by far the norm for all mature civilizations.The transcension hypothesis has significant and testable implications for our current and future METI and SETI agendas. If all universal intelligence eventually transcends to black-hole-like environments, after which some form of merger and selection occurs, and if two-way messaging (a send–receive cycle) is severely limited by the great distances between neighboring and rapidly transcending civilizations, then sending one-way METI or probes prior to transcension becomes the only real communication option. But one-way messaging or probes may provably reduce the evolutionary diversity in all civilizations receiving the message, as they would then arrive at their local transcensions in a much more homogenous fashion. If true, an ethical injunction against one-way messaging or probes might emerge in the morality and sustainability systems of all sufficiently advanced civilizations, an argument known as the Zoo hypothesis in Fermi paradox literature, if all higher intelligences are subject to an evolutionary attractor to maximize their local diversity, and a developmental attractor to merge and advance universal intelligence. In any such environment, the evolutionary value of sending any interstellar message or probe may simply not be worth the cost, if transcension is an inevitable, accelerative, and testable developmental process, one that eventually will be discovered and quantitatively described by future physics. Fortunately, transcension processes may be measurable today even without good physical theory, and radio and optical SETI may each provide empirical tests. If transcension is a universal developmental constraint, then without exception all early and low-power electromagnetic leakage signals (radar, radio, television), and later, optical evidence of the exoplanets and their atmospheres should reliably cease as each civilization enters its own technological singularities (emergence of postbiological intelligence and life forms) and recognizes that they are on an optimal and accelerating path to a black-hole-like environment. Furthermore, optical SETI may soon allow us to map an expanding area of the galactic habitable zone we may call the galactic transcension zone, an inner ring that contains older transcended civilizations, and a missing planets problem as we discover that planets with life signatures occur at a much lower frequencies in this inner ring than in the remainder of the habitable zone.

Spatio-temporal constraints on the zoo hypothesis, and the breakdown of total hegemony

AbstractThe Zoo Hypothesis posits that we have not detected extraterrestrial intelligences (ETIs) because they deliberately prevent us from detecting them. While a valid solution to Fermi's Paradox, it is not particularly amenable to rigorous scientific analysis, as it implicitly assumes a great deal about the sociological structure of a plurality of civilizations. Any attempt to assess its worth must begin with its most basic assumption – that ETIs share a uniformity of motive in shielding Earth from extraterrestrial contact. This motive is often presumed to be generated by the influence of the first civilization to arrive in the Galaxy. I show that recent work on inter-arrival time analysis, while necessary, is insufficient to assess the validity of the Zoo Hypothesis (and its related variants). The finite speed of light prevents an early civilization from exerting immediate cultural influence over a later civilization if they are sufficiently distant. I show that if civilization arrival times and spatial locations are completely uncorrelated, this strictly prevents the establishment of total hegemony throughout the Galaxy. I finish by presenting similar results derived from more realistic Monte Carlo Realization (MCR) simulations (where arrival time and spatial locations are partially correlated). These also show that total hegemony is typically broken, even when the total population of civilizations remains low. The Zoo Hypothesis is therefore only justifiable on weak anthropic grounds, as it demands total hegemony established by a long-lived early civilization, which is a low probability event. In the terminology of previous studies of solutions to Fermi's Paradox, this confirms the Zoo Hypothesis as a ‘soft’ solution. However, an important question to be resolved by future work is the extent to which many separate hegemonies are established, and to what extent this affects the Zoo Hypothesis.

Asymmetry in Active SETI: A case for transmissions from Earth

The Search for Extraterrestrial Intelligence (SETI) typically presupposes contact with extraterrestrial civilizations much longer lived than humanity. Many have argued that given humanity's “youth,” the burden of transmitting should be placed on the extraterrestrial civilizations, which presumably possess more advanced technologies. These assumptions have contributed to the current emphasis on Passive SETI. Complementing this existing stress on Passive SETI with an additional commitment to Active SETI, in which humankind transmits messages to other civilizations, would have several advantages, including (1) addressing the reality that regardless of whether older civilizations should be transmitting, they may not be transmitting; (2) placing the burden of decoding and interpreting messages on advanced extraterrestrials, which may facilitate mutual comprehension; and (3) signaling a move toward an intergenerational model of science with a long-term vision for benefiting other civilizations as well as future generations of humans. Technological requirements for Active SETI are considered, and a case is made for Active SETI as a means for experimentally testing variants of the Zoo Hypothesis. Recommendations are provided for sustaining Passive and Active SETI and the communities that conduct these searches.

The zoo hypothesis

Extraterrestrial intelligent life may be almost ubiquitous. The apparent failure of such life to interact with us may be understood in terms of the hypothesis that they have set us aside as part of a wilderness area or zoo.