Fermi Paradox Research Articles

Formalizing the Fermi paradox and combining consistent explanatory hypotheses

AbstractA formalization of Fermi paradox inside the environment of classical propositional logic is proposed. The notion of Silentium Universi set is launched in order to establish that the Fermi paradox is truly paradoxical. Combining consistent explanatory hypotheses is taken into consideration and discussed inside this framework explaining what would count as a solution to the paradox. By the end, it is argued that Fermi paradox is an unsolvable problem in the domain of science.

The ethics of astrobiology: Humanity’s place in the cosmos and the extinction problem

Western philosophy has always stressed the importance of understanding the very nature of the universe and the relationship between humanity and the cosmos. Nowadays, astrobiology is used to shed light on that issue through a set of empirical data. Also, the Fermi paradox and the Rare Earth hypothesis could offer a suitable ground to properly interpret the proofs emerging from space exploration and direct and indirect observations from astronomers, that is, “we are likely the only intelligent species within the universe.” From this, we can say that maybe we are confronted with a cosmic bet. We should better wager on our cosmic importance as a species, otherwise the loss could be immense: the disappearance of the only species through which the universe enabled itself to understand its own secrets and cosmic treasures.

The Fermi paradox: impact of astrophysical processes and dynamical evolution

AbstractThe Fermi paradox has given rise to various attempts to explain why no evidence of extraterrestrial civilizations was found so far on Earth and in our Solar System. Here, we present a dynamical model for the development of such civilizations, which accounts for self-destruction, colonization and astrophysical destruction mechanisms of civilizations including gamma-ray bursts, type Ia and type II supernovae as well as radiation from the supermassive black hole. We adopt conservative estimates regarding the efficiency of such processes and find that astrophysical effects can influence the development of intelligent civilizations and change the number of systems with such civilizations by roughly a factor of $2$; potentially more if the feedback is enhanced. Our results show that non-equilibrium evolution allows for solutions in-between extreme cases such as ‘rare Earth’ or extreme colonization, including scenarios with civilization fractions between $10^{-2}$ and $10^{-7}$. These would imply still potentially large distances to the next such civilizations, particularly when persistence phenomena are being considered. As previous studies, we confirm that the main uncertainties are due to the lifetime of civilizations as well as the assumed rate of colonization. For SETI-like studies, we believe that unbiased searches are needed considering both the possibilities that the next civilizations are nearby or potentially very far away.

Self-replicating probes are imminent – implications for SETI

AbstractIn the early 1980s, the Sagan-Tipler debate raged regarding the interpretation of the Fermi paradox but no clear winner emerged. Sagan favoured the existence of ETI on the basis of the Copernican principle and Tipler favoured the non-existence of ETI on the basis of the Occam's razor principle. Tipler's stance was an expansion of the similar but earlier Hart declaration. However, crucial to the Tipler argument was the role played by self-replicating interstellar robot probes. Any technologically capable species will develop self-replication technology as the most economical means of exploring space and the Galaxy as a whole with minimal investment. There is no evidence of such probes in our solar system including the asteroid belt, ergo, ETI do not exist. This is a powerful and cogent argument. Counter-arguments have been weak including Sagan's sociological explanations. We present a Copernican argument that ETI do not exist – humans are developing self-replication technology today. We are developing the ability to 3D print entire robotic machines from extraterrestrial resources including electric motors and electronics as part of a general in-situ resource utilization (ISRU) capability. We have 3D-printed electric motors which can be potentially leveraged from extraterrestrial material that should be available in every star system. From a similar range of materials, we have identified a means to 3D print neural network circuitry. From our industrial ecology, self-replicating machines and indeed universal constructors are feasible. We describe in some detail how a self-replicating interstellar spacecraft may be constricted from asteroidal resources. We describe technological signatures of the processing of asteroidal material (which is expected to be common to most star systems), and the excess production of certain types of clay and other detritus materials. Self-replication technology is under development and imminent – if humans are pursuing self-replication technology, then by the Copernican principle, so would any technologically savvy species elsewhere. There is no evidence that they have.

Astrophysical existential threats: a comparative analysis

AbstractUsing a simple, coarse-grained Poisson process model, we calculate – for seven types of astrophysical catastrophe – both their individual and combined threat to complex lifeforms (extraterrestrial intelligences (ETIs)) throughout the Milky Way Galaxy. In terms of cumulative effects, we calculate that ETIs are likely to be astrophysically driven extinct on timescales of roughly once every 100 million years. In terms of comparative effects, large bolide impactors represent the most significant type of astrophysical contribution to the galaxy-wide debilitation of hypothesized ETI civilizations. Nonetheless, we conclude that astrophysical existential threats – whether taken singly or in combination – are likely insufficient, alone, to explain the Fermi Paradox. Astrophysical catastrophes, while both deadly and ubiquitous, do not appear to be frequent enough to wipe out every species in the Galaxy before they can attain or utilize spacefaring status.

Law of Gravity Blurred by Perturbed Planetary Orbits for Alien Observers

The Fermi paradox is the contradiction between the high probability for aliens and its lack of evidence. This is perhaps the most significant of all questions in astronomy. Nowadays, thousands of exoplanets have been detected, providing us more information directly from alien planets to revisit Fermi paradox. Over recent years, the detection of habitable exoplanets has grown rapidly, and most of them in multi-planet system with fairly compact structures, which is partly due to our observational techniques. In such systems, planets’ orbits are significantly perturbed by gravitational interactions from each other. To travel within or out of a planetary system, one must understand the law governing planetary motion, but can extraterrestrials deduce the universal law of gravitation by observing planets in their system, as Johannes Kepler and Isaac Newton had done? Here we show that due to the close planetary orbits in systems hosting habitable exoplanets, planetary orbits significantly deviate from the Keplerian orbit. In our N-body simulation over a period of 300 days, out of the ten planetary systems which all include habitable exoplanets in our sample, the mean anomaly deviates from a Keplerian orbit by more than 5 degrees while the system remains stable as the semi-major axis remains relatively constant. This would significantly complicate what the observers on those planets observe as the motion in the system would not appear to have a pattern periodically. Although planets indeed affect each other in all systems, the compact nature of these systems have magnified the effect and provide no way for the extraterrestrials inhabiting those planets to discover the universal law of gravitation. Extraterrestrials lacking the law of gravity definitely cannot facilitate traveling beyond their planets. That could be one possible resolution of Fermi paradox, reducing the population of high-developed civilization in Universe.

SETI From the Perspective of Intercivilizational Politics

The possibility of SETI finding extraterrestrial biological or technological signatures is becoming less hypothetical. Social science scholarship has responded with a growing literature that examines the possible social, cultural, and political implications of a major SETI discovery. This article extends this social science perspective by speculating about politics at the other end of contact. I argue that the questions of whether another civilization would apply resources to SETI like efforts, who they would wish to contact, and their motivations for searching for intelligent life, are essentially questions about the politics of possible but unknown societies.I attempt to show the utility of this comparative politics perspective by applying it to Fermi's Paradox. The perspective of intercivilizational politics reframes the paradox as a problem of collective action and avoids two problematic assumptions widely found in the literature. First, it is probably impossible to predict what would be rational for extraterrestrial intelligence without knowing their appetite for risk. Second, if an extraterrestrial civilization shares similar patterns to our development, then many proposed solutions to Fermi's Paradox fall into the trap of assuming a unified rational actor. Instead, it is likely that possible interlocutors represent different political and social institutions from across an exocivilization.In addition, many famous commentators have argued that contact with another civilization would likely be disastrous for the less developed party, presumably us. So far, political scientists have added to this discussion by elaborating further on the possible dangers of a SETI discovery. However, I argue that reframing SETI efforts within the context of intercivilizational politics mitigates some of these concerns.

Asymptotic burnout and homeostatic awakening: a possible solution to the Fermi paradox?

Previous studies show that city metrics having to do with growth, productivity and overall energy consumption scale superlinearly, attributing this to the social nature of cities. Superlinear scaling results in crises called ‘singularities’, where population and energy demand tend to infinity in a finite amount of time, which must be avoided by ever more frequent ‘resets’ or innovations that postpone the system's collapse. Here, we place the emergence of cities and planetary civilizations in the context of major evolutionary transitions. With this perspective, we hypothesize that once a planetary civilization transitions into a state that can be described as one virtually connected global city, it will face an ‘asymptotic burnout’, an ultimate crisis where the singularity-interval time scale becomes smaller than the time scale of innovation. If a civilization develops the capability to understand its own trajectory, it will have a window of time to affect a fundamental change to prioritize long-term homeostasis and well-being over unyielding growth—a consciously induced trajectory change or ‘homeostatic awakening’. We propose a new resolution to the Fermi paradox: civilizations either collapse from burnout or redirect themselves to prioritizing homeostasis, a state where cosmic expansion is no longer a goal, making them difficult to detect remotely.

Where will they be: hidden implications of solutions to the Fermi paradox

AbstractSolutions to the Fermi paradox either deny the existence of extraterrestrials or offer alternative reasons to explain the non-occurrence of a first contact. While the latter, more optimistic approaches generally assume the existence of extraterrestrials, they simultaneously hint to limited future detectability. If solutions to the Fermi paradox are accepted as true, they must be evaluated in terms of how they affect the likelihood of success of future SETI efforts. Some solutions may lead to the so-called Fermi constraint: in order to explain why there has not been any contact so far, optimistic solutions to the Fermi paradox have to accept assumptions that, if the solution is assumed to be correct, indicate a very low probability of future contact. In other words: they are not here, and that is why they may never appear.

Catastrophe risk can accelerate unlikely evolutionary transitions.

Intelligent life has emerged late in Earth’s habitable lifetime, and required a preceding series of key evolutionary transitions. A simple model (the Carter model) explains the late arrival of intelligent life by positing these evolutionary transitions were exceptionally unlikely ‘critical steps’. An alternative model (the neocatastrophism hypothesis) proposes that intelligent life was delayed by frequent catastrophes that served to set back evolutionary innovation. Here, we generalize the Carter model and explore this hypothesis by including catastrophes that can ‘undo’ an evolutionary transition. Introducing catastrophes or evolutionary dead ends can create situations in which critical steps occur rapidly or in clusters, suggesting that past estimates of the number of critical steps could be underestimated. If catastrophes affect complex life more than simple life, the critical steps will also exhibit a pattern of acceleration towards the present, suggesting that the increase in biological complexity over the past 500 Myr could reflect previously overlooked evolutionary transitions. Furthermore, our results have implications for understanding the different explanations (critical steps versus neo-catastrophes) for the evolution of intelligent life and the so-called Fermi paradox—the observation that intelligent life appears rare in the observable Universe.

Cosmic Queries: StarTalk's Guide to Who We Are, How We Got Here, and Where We’re Going

Cosmic Queries: StarTalk's Guide to Who We Are, How We Got Here, and Where We’re Going

Is Blackout the Cause of Fermi's Paradox?

Is Blackout the Cause of Fermi's Paradox?

Lotka-Volterra models for extraterrestrial self-replicating probes.

A sufficiently advanced extraterrestrial civilization can send out a swarm of self-replicating probes for space exploration. Given the fast-growing number of such a probe, even if there is only one extraterrestrial civilization sending out such probes in the Milky Way galaxy, we should still expect to see them. The fact that we do not consist part of the Fermi paradox. The suggestion that self-replicating probes will eventually mutate to consume their progenitors and therefore significantly reduce the number of total probes has been investigated and dismissed in the literature. In this work, we revisit this question with a more realistic Lotka–Volterra model and show that mutated probes would drive the progenitor probes into “extinction,” thereby replacing them to spread throughout the galaxy. Thus, the efficiency of mutated probes in reducing the total number of self-replicating probes is even less than previously thought. As part of the analysis, we also suggest that, somewhat counter-intuitively, in designing self-replicating probes, one should not program them to stop replicating when sufficient mutation causes the probes to fail to recognize the progenitor probes as “self.”

Self-conscious intelligent technological societies in the universe: a simple direct approach to probable astrosociological realistic scenarios

AbstractWe present an alternative equation to estimate the probable numberNof self-conscious intelligent technological societies (SCITSs) within the radius of the observable universe. This equation has only one poorly-known factor,Pc, the SCITS's formation probability, which can be estimated within an uncertainty by a factor of 102(10−11≤Pc≤ 10−9) by applying the restriction imposed by Fermi's Paradox. The SCITS's formation rate for a typical spiral galaxy is then estimated as ≈1 civ Gyr−1. For a very optimistic maximum life expectancy ≈108yr, the conclusion is that two civilizations never coexist in the same galaxy. Our estimated values forPcare compatible with current biological and astrophysical evidences. We also propose an alternative astrosociological classification scheme which enables us to speculate about possible evolutionary paths for SCITSs in the universe. The so-called ‘Closed Bottle Neck’ (CBN) scenario suggests that civilizations are no exit evolutionary ways. We argue that simply there would not be interstellar travels nor Galaxy colonization or a Galactic Club. Thus Fermi's Paradox results eliminated, and the perspectives about the future of our own civilization may not be positive.

Jules Verne's Formulation of the Fermi Question

Abstract Jules Verne's novel Around the Moon envisions the circumlunar flight of a crewed projectile around the lunar farside ending with a safe return to Earth. The novel is justifiably famous, partly because of certain parallels it contains to the U.S. Apollo program a century later. What is less appreciated is that the novel contains a rather direct statement of what would later become known as the Fermi Question or Fermi Paradox.

History and future of life on Earth - a synthesis of natural science and theology

"A synthesis of research results of modern natural sciences and fundamental statements of the Christian faith is attempted. The creation of the universe is addressed. Four important events in the history of the Earth as well as the diversity of living beings are shortly discussed. There are good reasons to believe that the universe was created by a transcendent superior being, which we call God, and that this superior being intervened in evolution and Earth history to promote the development of intelligent life. Furthermore, it can be concluded that intelligent life is very rare in the universe. This is the explanation for the “Fermi paradox”. Intelligent life on planet Earth has cosmic significance. The overabundance of this universe inspires the hope for participating in the fulfilled eternity of the Creator in transcendence. Prehistoric humans had long had hope for life after biological death. While scientific speculation about the end of the universe prophesies scenarios of destruction, the Christian faith says that humanity is destined to be united with Jesus Christ. Furthermore, all evolution will be completed with the Creator in transcendence. Then the whole of creation will “obtain the freedom of the glory of the children of God”. From the first primitive living cell, an abundance of the most diverse living beings has evolved. Comparably, humanity has differentiated into a plethora of different cultures. This entire abundance will find its unification and fulfilment in transcendence with the Creator of the universe, without its diversity being erased."

On the Resolution of a Weak Fermi Paradox

In this paper we consider the Fermi's paradox (FP) and propose a possible resolution in the context of super-advanced alien civilizations. In this sense it can be regarded as to be the weak Fermi paradox (WFP). By assuming that super advanced extraterrestrials (ET) exist and are capable of constructing a huge ring-like megastructure around a pulsar or a main sequence star (MSS) to consume its emitted energy, we consider the stability problem of the ring, studying the out of plane dynamics.

Formulation and resolutions of the red sky paradox

Most stars in the Universe are red dwarfs. They outnumber stars like our Sun by a factor of 5 and outlive them by another factor of 20 (population-weighted mean). When combined with recent observations uncovering an abundance of temperate, rocky planets around these diminutive stars, we are faced with an apparent logical contradiction-Why do we not see a red dwarf in our sky? To address this "red sky paradox," we formulate a Bayesian probability function concerning the odds of finding oneself around an F/G/K-spectral type (Sun-like) star. If the development of intelligent life from prebiotic chemistry is a universally rapid and ensured process, the temporal advantage of red dwarfs dissolves, softening the red sky paradox, but exacerbating the classic Fermi paradox. Otherwise, we find that humanity appears to be a 1-in-100 outlier. While this could be random chance (resolution I), we outline three other nonmutually exclusive resolutions (II to IV) that broadly act as filters to attenuate the suitability of red dwarfs for complex life. Future observations may be able to provide support for some of these. Notably, if surveys reveal a paucity of temperate rocky planets around the smallest (and most numerous) red dwarfs, then this would support resolution II. As another example, if future characterization efforts were to find that red dwarf worlds have limited windows for complex life due to stellar evolution, this would support resolution III. Solving this paradox would reveal guidance for the targeting of future remote life sensing experiments and the limits of life in the cosmos.

Reconfiguring SETI in the microbial context: Panspermia as a solution to Fermi's paradox

All SETI (Search for Extraterrestrial Intelligence) programmes that were conceived and put into practice since the 1960s have been based on anthropocentric ideas concerning the definition of intelligence on a cosmic-wide scale. Brain-based neuronal intelligence, augmented by AI, are currently thought of as being the only form of intelligence that can engage in SETI-type interactions, and this assumption is likely to be connected with the dilemma of the famous Fermi paradox. We argue that high levels of intelligence and cognition inherent in ensembles of bacteria are much more likely to be the dominant form of cosmic intelligence, and the transfer of such intelligence is enabled by the processes of panspermia. We outline the main principles of bacterial intelligence, and how this intelligence may be used by the planetary-scale bacterial system, or the bacteriosphere, through processes of biological tropism, to connect to any extra-terrestrial microbial forms, independently of human interference.

Новая гипотеза разрешения парадокса Ферми

The study aims to formulate a new hypothesis to explain the Fermi paradox. The article considers development of civilisations with respect to electronic virtual reality (EVR). Special attention is paid to shifting the research from physical space to the world of EVR. The study is novel in that it puts forward the author’s hypothesis to solve the Fermi paradox based on the ontological and existential approach to the level of civilisation development. On the premise of such a prominent essential characteristic of human beings as freedom, the authors distinguish between the “hard” and “soft” world. The result of the study amounts to introducing the idea that civilisations which achieved a certain level of intellectual and moral development make a transition to EVR.