Reaction to Oman-Reagan (2016)

In this popular science article on meta-SETI, Oman-Reagan voices his concern regarding how our physical presentation to an alien intelligence may come across as offensive in ways that we cannot yet imagine. This is referring to an actual physical encounter between humans and ET who come to visit us (though technically it also applies to cases of us visiting them, but our technology precludes this option presently.) Fanciful as it may sound, he does raise concerns that we perhaps have not up until now considered if such an occurrence were to take place. The problem is that, although we may attempt to take every precaution to present a benevolent outward persona, we are limited by our fundamental biology and hence may inadvertently trigger a negative response from the visitors. To illustrate this point, Oman-Reagan brings up scenarios where they view just our gaze or gaseous respirations as acts of aggression, even though they are critical aspects of our biology. There is even a possibility where the perception of time is different between them and us. The metabolism or rate of life of their species may be such that many of their generations will pass for a single human’s or vice versa. This complicates matters of communication between the “slow” and “fast” race. Alternatively, their social awareness may prohibit or require certain modes of behavior which we do not understand, as pointed out by Oman-Reagan. These differences in cultural mores compounded with biological evolution histories dramatically complicate the possibility for a positive first interaction.

This article reminded me of the situation presented in the recent first contact film “Arrival,” where the minds of the aliens operate significantly differently from ours. Warning: film spoilers ahead! Their perception of time is distinct from ours because their language allows them to convey complex ideas simultaneously. This idea is an extrapolation of the Sapir-Whorf hypothesis of anthropology, the idea that one’s perception of reality stems from the grammatical structure and vocabulary of their language, to the aliens. For example, if a people had no word for the color green, then the hypothesis suggests that would have no ability to conceptulize or discuss the idea of green, and thus perhaps may not even perceive it in nature. This is probably untrue in the case of humans however, since we all share the same wavelength coverage and responsiveness to pigments in the ocular cones and rods. Therefore each human has the opportunity to at least perceive green (excluding color-blindedness) regardless of whether or not there exists a word for green in their particular language. In the case of the heptapods of Arrival, their understanding of time is non-linear and enabled by their circular and atemporal representation of information. While this is a different kind of temporal distinction than what is talked about in this article, it does show how biological differences in cognition may adversely affect the first encounter.

Reaction to Gertz (2016)

Gertz composes a compelling document in which he expounds upon the shortcomings and nearsightedness of the METI initiative. In summary, Gertz is condemning the proponents of METI and justifies his position very effectively. I have a strong positive reaction to this document for reasons that I will explain.

Because the extent of our oldest radio leakage dates to only some 80 years ago, our radio bubble extends to a sphere with a radius of 80 lightyears. However, as Gertz points out, there are difficulties in detecting such low energy, isotropically radiated emissions that to overcome would require a truly colossal receiver, or some more exotic technology such as a stellar gravity lens telescope. Therefore, granting the existence of an advanced technology within our radio sphere with the desire to communicate with emerging civilizations, the furthest away they can be if we are to be receiving their return message presently is 40 light years. This is a 40 years light travel time each way, so that if they received our leakage from 1938 in our year 1978 and immediately replied, we would now be receiving them in the year 2018. However, since no evidence of such a return salutation has until now been detected, we are presented with only two possibilities: 1), there are no radio-communicative civilizations within 40 lightyears (they do not exist), or 2), they are listening and they have heard us, but for some reason they are perpetuating silence. (I exclude the case where they exist but are not listening by definining “intelligence” as radio-capability.)

In the section entitled “Someone has to be the first to transmit,” Gertz raises the point that METI-ists contend that civilizations would probably be much older than us, and therefore would have been transmitting early on. That they are not suggests that either they do not exist or again have some reason to not transmit. This reasoning is consistent with the second conclusion from above, and reading this called to my mind a novel that I read last year. Although suggesting a pattern of behavior is a sociological argument that fails on a universal level due to the requirement that every such civilization will have to remain radio-quiet for all time, there is some merit to consider it as a near term solution to the Fermi paradox. In the science fiction novel “The Dark Forest,” author Cixin Liu offers a hypothetical solution to the Fermi paradox on the sociological argument that all sufficiently realized intelligences will observe radio-silence. The argument is predicated on two basic “axioms” and observations. The two “axioms” are that 1) life will naturally seek to preserve itself, and 2) outward growth is a natural consequence of life. Then, the two observations are that 1) resources in the universe are finite, and 2) instantaneous communication is impossible. As far as physics is now understood, these assertions are sound. Therefore, applying these axioms and observations to the case of two nearby civilizations which have recently come into contact with one another, they can never know the other’s true intentions whether hostile or benevolent due to the constraint of time-delayed communication, what Liu calls the “chains of suspicion”. Therefore, they must prepare for the worst outcome and pre-emptively strike in order to ensure they preserve themselves and their future access to the other’s resources. While the suspicious behavior is somewhat anthropomorphic, many prominent scientists also hold similar beliefs.

For every two seconds that pass without a return message, the “null sphere“ within which there probably do not exist any radio-capable intelligences increases in radius by one lightsecond. Therefore, METI to very nearby stars is probably a waste of effort for now because if conclusion 1) from above is true, then there aren’t any civilizations in the null sphere. And if conclusion 2) from above is true, then it would be in our best interest to remain quiet, at least until we understand why.

Though it seems METI is not the most productive activity for us for now, I feel more forgiving towards Frank Drake’s original Arecibo message in 1974 because of multiple reasons. Firstly, the protocols and understandings that we have arrived at with regards to such activities had not yet been developed. Secondly, the message was short in duration and not repeated, so that the probability that anyone actually receives it in the remote future is very low. And thirdly, and probably most importantly, M13 is some 22,000ly distant, so the very soonest that we can realize this as being a mistake is some 44,000 years from now, and probably much longer than that. Though I won’t claim to know the future, I suspect that the human condition will be dramatically changed by the year 46,000CE in ways that we cannot yet conceptualize or understand but which may prepare us for encounters with extraterrestrials.

However, in the case of Shostak’s METI initiative, the goal seems to be to send messages to the nearest star systems. Gertz and others have shown why this is at best pointless or at worst very dangerous, but to compound the problems, as Gertz’s points out, there is no observing plan for follow-up at some time in the future equal to twice the light travel time when we could soonest expect a reply. This combined with all the other problems associated with being the first to transmit compels me to condemn the METI initiative, at least as it is currently formulated and for the near term future.

Reaction to Oliver (1979)

In this document, scientist Bernard M. Oliver, a scientist and founder of Hewlett-Packard company, motivates the need for international preservation and protection of what he perceived to be the optimal window from which we may receive signals from extraterrestrial intelligence, namely the “Water Hole.” Among his many contributions to the fields of radio and electronics, he also had an interest in the Search for Extraterrestrial Intelligence (SETI). Prior to 1979, previous studies had already shown that the region bounded by the spin-flip transition of Hydrogran at 1.42GHz and the hydroxyl line at 1.66MHz was a prime region of frequency space to search for pulsed signals. At the time, several navigational satellites had been planned who would operate within these frequencies and disrupt such a search. Therefore, as a prophylactic measure, Oliver suggested a re-examination of the merits of the water hole and of the radio search in general.

He presents a case for electromagnetic radiation being the medium through which an advanced intelligent society would aim to transmit their communications and beckons to lower societies based on its satisfaction of multiple criteria. Important among these criteria are the need for the signal to be of low power, to not be absorbed or deflected as it passes through interstellar media and their corresponding electromagnetic fields, travel very quickly, and exceed the background levels. These criteria mostly preclude massive particles and favors low energy electromagnetic radiation, hence lending support to the idea of interstellar radio communications. He also presents a case that the water hole is the best window into the microwave and radio based on the low amounts of background contamination from contributions to the spectral noise power density like synchrotron radiation (which dominates below 1GHz) and quantum spontaneous emission (dominating above 60GHz). From free space, the case could be made for the frequency space between these upper and lower limits, however, when moved to the terrestrial frame, it becomes clear that significant portions of window are obscured by atmospheric molecular absorption. He also takes into consideration the motion of the Earth and the resultant Doppler drift, which increases the noise by a factor ^1/2, which dramatically builds the case for the hydrogen-hydroxyl water hole.

He admits to the romanticism and chauvinism of holding such a perspective, that water-based lifeforms would convergently arrive at such a bandpass for their communications. He acknowledges these shortcomings but insists that water is likely to be a common solvent for biochemistry to take place in throughout the universe, and contends that romanticism may be an inherent feature of highly evolved, sentient beings akin to humans.



Reaction to Sagan & Newman (1983)

In this paper, Sagan & Newman respond to the faulty conclusions derived from the solipsist worldview and offer their response to the 1980 Tipler paper entitled “Extraterrestrial Intelligent Beings do not Exist.” In that paper, Tipler argues that the probability of the emergence of another intelligent civilization in our galaxy is so low as to have not possibly have occurred, and thus we are the only such example in the Milky Way. He justifies this assertion with a variety of lines of reasoning. Firstly, that the problem of interstellar colonization can be reduced to two components, namely: a) the development of rocket propulsion technology to the modern level, and b) the development of a universal assembler or von Neumann machine. Both of these he presumes are feats that ought to appear early on in the list of accomplishments of a mature technological society. Consequently, upon mastery of these technologies, the timescale for galactic colonization would only be some 300 million years, a value that is short relative to the age of the galaxy. Secondly, he uses Drake’s Equation to suggest that the probability of the development of spacefaring civilizations is something like 10^-11 based on biological arguments, and since there are something like 10^11 stars in the galaxy, it is reasonable to think that there may only be one. In response to this, Sagan & Newman point out that the inevitability and reproduction fidelity of von Neumann machines cannot be guaranteed. It must be either that the builders can guide the proliferation of the von Neumann machines or they cannot; in the former case, they could program them to obey a non-interventionist code and avoid systems where life has emerged, and in the latter their exponentiation will continue unchecked until they the dominate the matter of the galaxy.

Sagan & Newman also revisit a calculation performed relating galactic colonization timescale to the historical colonization time across North America. This paper and their previous work taken as a unit are valuable because they represent one of the earliest attempts to model the timescale for galactic colonization. Unfortunately, the glaring flaw in their simulation was to treat the stars in the galaxy as static entities and simply allow a bubble to expand outward from a localized region, similar to molecular diffusion. This ignores the dynamical shearing that occurs with a differentially rotating galactic plane, allowing the separations between the stars to vary, accelerating the mixing and hence shortening colonization time. A new model accounting for this feature would be a valuable step towards a more realistic estimate of t_col.

Nonetheless, they remain steadfastly neutral regarding the ETI question and denounce the conclusions of the solipsist viewpoint by insisting on an experimental radio search.

Reaction to Tipler (1981)

In this brief document, Tipler reviews the history and  development of the question of the plurality of worlds/extraterrestrial intelligence (ETI), from the earliest Greek thinkers through to the modern scientific era. This “meta” paper aims to justify the conclusion that the modern proliferation and acceptance of the ETI question is a consequence of developments in philosophical, theological, and empirical reasoning that been made throughout the centuries. He constructs a temporal chain linking advancements in thinking on the subject (supported by direct quotations of the primary sources), revised and modified with each new generation, that continues through to the current time. This paper is relevant to our discussion of SETI because it is one of few which attempt to comprehensively depict the status of thinking regarding the ETI question throughout history. In particular, the Greeks were separated into two schools, those who subscribed to plurality and plenitude, and those who objected; the Stoics, Pythagoreans, and Epicureans fell into the former camp, whereas the Platonists and Aristotelians the latter.  Since the cosmology of Aristotle was highly influential on the thought of the medieval scholars, the early Church Doctors concluded the concept of plurality to be antithetical to Christian theology. Not until the time of the Copernican Revolution and the emergence of the Principle of Mediocrity did the idea that other worlds could be inhabited reemerge,  and when it finally did, it did so with great force. One interesting feature of the history that this blogger did not as of yet know was the opinion held by the early Darwinists through to the modern evolutionary biologists, which turns out to be a pessimistic one on the grounds of the improbable series of millions of mutations which are requisite for the development of human-level intelligence. Tipler concludes the history at the end of the 20th century, when feelings regarding the ETI are positive due to advances in radio communication technology, theories of stellar and planetary formation and abiogenesis, and the contemporary cosmology which supported the thesis. Since this paper is not really a scientific paper in itself, but rather an exploration of the history of scientific and pre-scientific thought on the matter, it is fitting that a subsequent paper, to be written either presently or at some future point, should contain a continued account of the ETI question by way of a comprehensive treatment of SETI developments through the 21st century.

Reaction to Bracewell (1960)

This paper describes a new search method and suggests a Schelling point for contacting extraterrestrial civilizations through detection of their emissaries in our solar system. Bracewell discusses the difficulty with maintaining an array of radio transmitters beaming signals to all nearby star systems in the style of Cocconi & Morrison (1959). The method for handling this problem is primarily thought-based.  Bracewell argues that it would be more feasible to send probes to each system and wait for the emergence of a radio-capable technology in that system before relaying such information back to the advanced civilization. They further argue that due to the difficulties with sending macroscopic objects across interstellar distances, it would be worthwhile to outfit such a probe with advanced communicative and computational capabilities. This paper is novel for the suggestion that such “Bracewell” probes may exist and that it may be in our interest to search for evidence of them in our own solar system. He concludes that a null detection of such a probe would constitute evidence that either such probes are unfeasible or that the superior community is at such a distance that the possibility of successful contact with us is low. They admit the possibility of longer-lived, sustained civilizations which have bypassed the low mean lifespan they determine from their probability experiment. If we limit the search for Bracewell probes to simply searching for an object in the solar system with radio emission, it may be possible at some point in time to deem the search complete. However, advanced civilizations may have access to technologies which are unknown or undetectable to us, which would make their detection impossible to our instruments, thereby leading to an un-ending search with no definitive conclusion. Therefore, even in our modernity we cannot dislodge the primary idea of this paper. The obvious follow up to this paper would be targeted observational searches for the aforementioned radio emissions emerging anomalously and unnaturally within our own solar system. A Herculean project for the future would be a surface mapping of the majority of macroscopic objects in orbit around the Sun at high resolution and then employing machine-learning algorithms to hunt for sedentary, exposed Bracewell probes of perfect geometric dimension.