Active SETI Research Articles

Saved by the Dark Forest: How a Multitude of Extraterrestrial Civilizations Can Prevent a Hobbesian Trap

Abstract The possibility of extraterrestrial intelligence (ETI) exists despite no observed evidence, and the risks and benefits of actively searching for ETI (Active SETI) have been debated. Active SETI has been criticized for potentially exposing humanity to existential risk, and a recent game-theoretical model highlights the Hobbesian trap that could occur following contact if mutual distrust leads to mutual destruction. We argue that observing a nearby ETI would suggest the existence of many unobserved ETI. This would expand the game and implies that there may be a mechanism that prevents ETI from attacking us. As a result, the Hobbesian trap would be avoided if both parties assumed the other is not likely to attack.

Intentional astrobiological signaling and questions of causal impotence

My focus is on the contemporary astrobiological activity of Messaging ExtraTerrestrial Intelligence (METI). This intentional astrobiological signaling typically involves embedding digital communications in powerful radio signals and transmitting those signals out into the cosmos in an explicit effort to make contact with extraterrestrial others. Some who criticize METI express concern that contact with technologically advanced extraterrestrial life could be seriously harmful to Earth or humanity. One popular response to this critique of messaging is an appeal to causal impotence sometimes referred to as the ‘Barn Door’ Argument—we are already engaged in many other detectable activities not intended for cosmic communication. If the Barn Door Argument is correct, then those who engage in messaging arguably have a moral excuse. They are permitted to continue messaging because there is no point in abstaining. I develop three ways in which the claim of causal impotence in the Barn Door Argument could be understood. I evaluate each of these in turn and demonstrate that only one is appropriate to contemporary messaging. However, this interpretation does not generate the moral excuse on which the proponents of the Barn Door Argument rely; thus, the argument fails. Finally, I entertain and respond to candidate objections.

Identifying optimal decision-making strategies and determining effective messaging to maximize the expected outcomes of potential human–extraterrestrial encounters

Abstract The question of whether extraterrestrials exist has driven both the search for extraterrestrial intelligence (SETI) and some attempts of messaging to extraterrestrial intelligence (METI). Nevertheless, no data-driven or theory-based behavioural policy has been suggested. Here we simulate a comprehensive set of human–extraterrestrial strategic interactions, modelled as two-by-two game-theoretic matrices. We examine a sample of possible outcomes by relying on the theory of subjective expected relative similarity (SERS), which takes into account both the expected payoffs and the extent of strategic similarity – the prospects of the opponent making identical choices. Simulation results suggest: focusing messaging efforts on signalling of complete strategic similarity, monitoring potential alien communications for similarity-indicating signals, and using risk-averse decision rules for policy planning and decision-making. The discussion puts forward three guidelines for METI initiatives and addresses the relevance of the findings to human conflict management.

We Come in Peace? A Rational Approach to METI

Even if our messages are unlikely to be heard, the threat to our species that contact with extrasolar entities poses means that determining what content to include in Messaging Extraterrestrial Intelligence (METI) messages presents serious ethical questions. I tackle one of those questions: Should our opening move in interstellar diplomacy be a peaceful overture or a belligerent warning?Those in favor of broadcasting peaceful overtures sometimes argue that the ability to interpret a METI message requires advanced technology and communicative skills, which in turn depends on a suite of social capacities and prosocial attitudes. We can thus assume that any species which receives our message will at least be open to peaceful coexistence.I show that this argument does not hold up under scrutiny because it seriously underestimates just how different an advanced alien intelligence could be from Earth life. An extraterrestrial entity might be similar to us: a society composed of cooperating autonomous individuals. But it could also be an instance of eusocial hive cooperation, or an evolving superindividual, which develops not through natural selection but through learning. These possibilities blow some of the premises of the argument for peaceful overture out of the water.I conclude by making a case that, if we send any message at all, defensive belligerence is the more prudent diplomatic tactic, even in case of serious technological asymmetry.

Mutual Detectability: A Targeted SETI Strategy That Avoids the SETI Paradox

Abstract As our ability to undertake searches for extraterrestrial intelligence (SETI) grows, so does interest in the controversial endeavor of messaging extraterrestrial intelligence (METI). METI proponents point to the SETI Paradox—if all civilizations refrain from METI then SETI is futile. I introduce mutual detectability as a game-theoretic strategy to increase the success potential of targeted SETI. Mutual detectability comprises four laws that establish how SETI participants can engage each other based on mutual evidence of mutual existence. I argue that the party whom both SETI participants can judge to have better quality evidence, or common denominator information (CDI), has an onus to transmit to avoid the SETI Paradox. Transiting exoplanets within the Earth Transit Zone form a target subset that satisfies mutual detectability requirements. I identify the intrinsic time-integrated transit signal strength, which for Earth is 103 L ⊙ ppm hours yr−1, as suitable CDI. Civilizations on habitable-zone planets of radius have superior CDI on us, and so under the mutual detectability framework have game-theory incentive (onus) to transmit. While the onus to transmit falls on us for habitable planets around L * > L ⊙ stars, considerations of relative stellar frequency, main-sequence lifetime and planet occurrence rates mean that such systems are likely to be in a small minority. Surveys of the Earth Transit Zone for Earth-analog transiting planets around subsolar luminosity hosts would facilitate targeted SETI programs for civilizations who have game-theory incentive to transmit signals to us. A choice to remain silent, by not engaging in METI toward such systems, does not in this case fuel concerns of a SETI Paradox.

Some Culturological Aspects of METI Problems with EM Radiation

Until the beginning of 2020, from 1974 to 2017, sixteen interstellar radio messages were sent to hypothetical extra-terrestrial civilizations. They were sent from different radio telescopes and had different contents. The METI (Messaging Extraterrestrial Intelligence) projects had different concepts, some of which seem highly controversial. Therefore, a short list of criteria for future METI projects is proposed. As an example, we suggest an interstellar message in the radio frequen-cy range of the electromagnetic spectrum that we call “Golden Wings of a Lemniscate” (GWL). The GWL project is a sim-ple message from Earthlings about their intelligence and readiness for interstellar contact. The digital part of the message contains ten images of lemniscates. The right half of the lemniscate includes the Golden Ratio concept with graphical drawings; the left parts of the lemniscate remain empty for ET reply messages. The experience of developing new projects of interstellar messages, initiative or response, is valuable. In the process of this work, various aspects of METI will be in-vestigated: scientific, technical, informational, cultural, ethical, educational, sociological, psychological, historical, etc.

The Search for Extraterrestrial Intelligence: A Realpolitik Consideration

In the vigorous academic debate over the risks of the Search for ExtraTerrestrial Intelligence (SETI) and active Messaging ExtraTerrestrial Intelligence (ETI) (METI), a significant factor has been largely overlooked. Specifically, the risk of merely detecting an alien signal from passive SETI activity is usually considered to be negligible. The history of international relations viewed through the lens of the realpolitik tradition of realist political thought suggests, however, that there is a measurable risk of conflict over the perceived benefit of monopoly access to ETI communication channels. This possibility needs to be considered when analyzing the potential risks and benefits of contact with ETI.

SETI & METI: An Indian Perspective

ABSTRACTCritiques consider Search for Extraterrestrial Intelligence (SETI) and Messaging Extraterrestrial Intelligence (METI) immoral for various reasons. This article is a response to SETI-METI from an Indian perspective, both classical Hindu and Roman Catholic. The article begins with a brief account of what the space programme in India looks like today. Then this article makes two claims: (1) the existence or non-existence of extraterrestrials is not a threat to the Indian mind as the Indian worldview provides sufficient tools to accommodate extraterrestrials; plus (2) Roman Catholic moral theology should reframe its ethical thinking with an inclusive cosmic paradigm to embrace the extraterrestrials.

Active SETI and the Problem of Research Ethics

ABSTRACTThis article argues that research involving active SETI, or sending messages toward possible extraterrestrial intelligence (METI), is not ethically justifiable. As a way of working some of the ethical problems associated with METI, I approach the sending of a message from the perspective that it represents a research endeavor involving sentient beings and therefore, should undergo review by a university institutional review board (IRB). As such, METI should be expected to meet several criteria expected by IRBs as being necessary components of ethically justifiable research. By considering issues of proportionality, justice, informed consent, the likely success of obtaining desired results, and necessity and considering risks and benefits to research subjects, as well as the mandate to do no harm, it is evident that METI does not meet the requirements for ethical research on human subjects and, thus, should not be considered ethical when it comes to nonhuman sentient beings.

The “Barn Door” Argument, The Precautionary Principle, and METI as “Prayer”—an Appraisal of the Top Three Rationalizations for “Active SETI”

ABSTRACTProponents of Active SETI, or METI, defend their messaging-to-aliens agenda with fallacious arguments like the Barn Door Excuse, that technologically advanced extraterrestrials must have already listened to our radio leakage, (e.g. “I Love Lucy”), hence more direct beaming will not betray Earth’s location. Further, sending pinpointed, collimated messages will only lead to positive outcomes. In fact, laser-like “messages” are far more powerful at great distances than old-time television, and those concerns about potential downsides should be appraised by scientific risk-assessment. It is argued that METI is psychologically driven as a version of the ancient human practice of prayer.

Active SETI in Solar system neighborhood

In the search for habitable planets, the ultimate aspiration is finding an extraterrestrial technical civilization. We already lost a half of century for an active search for extraterrestrial civilizations. Should we lose another half? If all civilizations in the Universe are only recipients and not message-sending civilizations, then no SETI (Search for Extraterrestrial Intelligence) searches make any sense. Detecting only leaked radio signals is a hard job with present resources. Fear from the extraterrestrials is unfounded, having in mind physical difficulties and requirements of the interstellar travel. If possible extraterrestrial civilizations are more advanced than ours then they can pick up life signs from Earth easier than we can from their planets at present. Here we propose a scientifically based METI (Messaging to Extraterrestrial Intelligence) program.

Cargo Cults and the Ethics of Active SETI

The story of the cargo cult is one of contact between different groups of people with different types of technologies who interpret and construct a framework of interaction and communication that involves colonial officials, indigenous people, anthropologists, and military personnel. In this article, I use the idea of the cargo cult as a way of thinking about contact with an advanced extraterrestrial civilization. The cargo cult idea represents a useful tool in thinking about how contact with a civilization from another planet might unfold, particularly if we assume that there is some level of commonality in the epistemological frameworks guiding thoughts and behaviors on both sides. I conclude that careful consideration of the cargo cult phenomenon suggests that from a policy perspective groups interested in active SETI should be cautious about both the construction and sending of interstellar messages and that from a moral perspective it may be prudent to refrain from active SETI for the time being. Given the fact that a variety of groups and individuals are undertaking active SETI projects, this is a topic that needs to enter the radar of government organizations.

Policy options for the radio detectability of Earth

The METI risk problem refers to the uncertain outcome of sending transmissions into space with the intention of messaging to extraterrestrial intelligence (METI). Here, I demonstrate that this uncertainty is undecidable by proving that that the METI risk problem reduces to the halting problem. This implies that any proposed moratorium on METI activities cannot be based solely on the requirement for new information. I discuss three policy resolutions to deal with this risk ambiguity. Precautionary malevolence assumes that contact with ETI is likely to cause net harm to humanity, which remains consistent with the call for a METI moratorium, while assumed benevolence states that METI is likely to yield net benefits to humanity. I also propose a policy of preliminary neutrality, which suggests that humanity should engage in both SETI (searching for extraterrestrial intelligence) and METI until either one achieves its first success.

The Evolutionary Psychology of Extraterrestrial Intelligence: Are There Universal Adaptations in Search, Aversion, and Signaling?

To understand the possible forms of extraterrestrial intelligence (ETI), we need not only astrobiology theories about how life evolves given habitable planets, but also evolutionary psychology theories about how intelligence emerges given life. Wherever intelligent organisms evolve, they are likely to face similar behavioral challenges in their physical and social worlds. The cognitive mechanisms that arise to meet these challenges may then be copied, repurposed, and shaped by further evolutionary selection to deal with more abstract, higher-level cognitive tasks such as conceptual reasoning, symbolic communication, and technological innovation, while retaining traces of the earlier adaptations for solving physical and social problems. These traces of evolutionary pathways may be leveraged to gain insight into the likely cognitive processes of ETIs. We demonstrate such analysis in the domain of search strategies and show its application in the domains of emotional aversions and social/sexual signaling. Knowing the likely evolutionary pathways to intelligence will help us to better search for and process any alien signals from the search for ETIs (SETI) and to assess the likely benefits, costs, and risks of humans actively messaging ETIs (METI).

Universal Biology Does Not Prescribe Planetary Isolationism

ABSTRACTStephen Hawking’s caution against messaging extraterrestrial intelligence is a claim of universal biology and is probably false.

Toward understanding the active SETI debate: Insights from risk communication and perception

Insights from the robust field of risk communication and perception have to date been almost totally absent from the policy debate regarding the relative risks and merits of Active SETI or Messaging to Extraterrestrial Intelligence (METI). For many years, the practice (or proposed practice) of Active SETI has generated a vigorous and sometimes heated policy debate within the scientific community. There have also been some negative reactions in the media toward the activities of those engaged in Active SETI. Risk communication is a scientific approach to communication regarding situations involving potentially sensitive or controversial situations in which there may be high public concern and low public trust. The discipline has found wide acceptance and utility in fields such as public health, industrial regulation and environmental protection. Insights from the scientific field of risk communication (such as omission bias, loss aversion, the availability heuristic, probability neglect, and the general human preference for voluntary over involuntary risks) may help those who have participated in either side of the debate over Active SETI to better understand why the debate has taken on this posture. Principles of risk communication and risk perception may also help those engaged in Active SETI to communicate more effectively with other scientists, the public, with the media, and with policy makers regarding their activities and to better understand and respond to concerns expressed regarding the activity.

Clicks, whistles and pulses: Passive and active signal use in dolphin communication

The search for signals out of noise is a problem not only with radio signals from the sky but in the study of animal communication. Dolphins use multiple modalities to communicate including body postures, touch, vision, and most elaborately sound. Like SETI radio signal searches, dolphin sound analysis includes the detection, recognition, analysis, and interpretation of signals. Dolphins use both passive listening and active production to communicate. Dolphins use three main types of acoustic signals: frequency modulated whistles (narrowband with harmonics), echolocation (broadband clicks) and burst pulsed sounds (packets of closely spaced broadband clicks). Dolphin sound analysis has focused on frequency-modulated whistles, yet the most commonly used signals are burst-pulsed sounds which, due to their graded and overlapping nature and bimodal inter-click interval (ICI) rates are hard to categorize. We will look at: 1) the mechanism of sound production and categories of sound types, 2) sound analysis techniques and information content, and 3) examples of lessons learned in the study of dolphin acoustics. The goal of this paper is to provide perspective on how animal communication studies might provide insight to both passive and active SETI in the larger context of searching for life signatures.

The Benefits and Harm of Transmitting Into Space

Deliberate and unintentional radio transmissions from Earth propagate into space. These transmissions could be detected by extraterrestrial watchers over interstellar distances. Here, we analyze the harms and benefits of deliberate and unintentional transmissions relevant to Earth and humanity. Comparing the magnitude of deliberate radio broadcasts intended for messaging to extraterrestrial intelligence (METI) with the background radio spectrum of Earth, we find that METI attempts to date have much lower detectability than emissions from current radio communication technologies on Earth. METI broadcasts are usually transient and several orders of magnitude less powerful than other terrestrial sources such as astronomical and military radars, which provide the strongest detectable signals. The benefits of radio communication on Earth likely outweigh the potential harms of detection by extraterrestrial watchers; however, the uncertainty regarding the outcome of contact with extraterrestrial beings creates difficulty in assessing whether or not to engage in long-term and large-scale METI.

The benefits and harm of transmitting into space

Deliberate and unintentional radio transmissions from Earth propagate into space. These transmissions could be detected by extraterrestrial watchers over interstellar distances. This article analyzes the harm and benefits of deliberate and unintentional transmissions relevant to Earth and humanity. Comparing the magnitude of deliberate radio broadcasts intended for messaging to extraterrestrial intelligence (METI) with the background radio spectrum of Earth, we find that METI attempts to date have much lower detectability than emissions from current radio communication technologies on Earth. METI broadcasts are usually transient and several orders of magnitude less powerful than other terrestrial sources, such as astronomical and military radars, which provide the strongest detectable signals. The benefits of radio communication on Earth most probably outweigh the potential harm of detection by extraterrestrial watchers; however, the uncertainty regarding the outcome of contact with extraterrestrial beings creates difficulty in assessing whether or not to engage in long-term and large-scale METI.

The problem of active SETI: An overview

In the present paper (originally presented at the First IAA Symposium on Searching for Life Signatures hold at the UNESCO on 22–26 September 2008) I try to summarize the results of all my previous studies on active SETI and its possible dangers for us, also considering some new topics, in order to provide a possibly complete overview of the whole matter. First, I try to evaluate the possible risks of an indirect contact with aliens, from the social, cultural, and religious point of view; then, the possible risks related with receiving information about alien science and technology; finally, the risk that active SETI could increase the probability of a physical contact with hostile aliens. My conclusion is that active SETI is very unlikely to be dangerous for us, but, at present, such a possibility cannot be completely excluded. Surprisingly, it turns out that a very important point to be assessed in order to improve our evaluation of active SETI is the pace of our technological progress. Some suggestions about the policy that international community should adopt towards active SETI are also included.