Tsenamica

Essay on «Why might the Universe «need» Living Matter?

Essay on «Why might the Universe «need» Living Matter?

Vlad .V. Kamakin, Dr. Eng. 12.01.2022. Moscow, Russia.

                                                                             «If they have a mind, there is something
                                                                             in common with us, even though that mind
                                                                               evolved  on another planet».
From H.G. Wells.

At least two points of view on the role of Life in the Universe are possible. One is based on the idea of life as an accidental phenomenon not influencing the fate of the Universe, existing according to the principle: «The meaning and purpose of Life is only Life itself». The other, on the contrary, leaves living matter (LM), or more precisely, sentient LM, with the prospect of fulfilling some kind of universal mission. Let us consider the data sources on which our choice between these positions may be based. Today it is possible to make any kind of reasonable judgment about LM only relying on information about the Earth’s biosphere, because there is no data about Life outside of it. Meanwhile, there are publications on so-called «viable exoplanets», their number in galaxies, black holes, epochs of the Universe development, etc. In addition, since there is an intelligent LM on Earth in the form of a civilization, we can expect the same on the mentioned exoplanets. Rather, sharing the second point of view on the role of LM, we use the noted materials as an argument, understanding all their conventionality and leaving it to the reader to evaluate our position. The chosen genre of essays allows us to use sources ranging from scientific articles to information from Wikipedia. Note that by the Universe we mean its visible part — the Metagalaxy, containing ~ 5∙1011 galaxies with a total mass M ~1053 kg [1].

With no data on LM outside Earth, we conventionally assume its presence on a number of exoplanets, the presence of 60 of which has been confirmed as of October 2020. [2]. It is assumed that their number ~ 3∙108 in our spiral galaxy [3], typical for galaxies of this type. Let us estimate the expected mass Mv of an intelligent LM in the Universe, assuming that the possibilities for the development of life on exoplanets are close to those on the Earth. Earth’s biomass is ~ 2.4∙1032 kg, with an intelligent component — humans, in living weight ~ 3.5∙108 kg [4]. With the same fraction of this component in all viable exoplanets, multiplying the last value by their number ~ 3∙108, we get a possible mass of intelligent living-weight in the Galaxy on the order of 1017 kg. The Universe, as noted earlier, consists of 5∙1011 galaxies. About half of them are spiral galaxies, like our Galaxy [5]. With similar conditions of LM development in stellar systems of this type, the expected mass Mv of a reasonable LM would be 1028 kg. With the mass of the Universe M ~ 1053 kg, its possible fraction μ:  

                                                                              μ =  Mv / M  = 1028 / 1053 ~ 10-25

For comparison, the mass of the tobacco mosaic virus is 6.64∙10-20 kg. It can be seen that in the Universe a reasonable LM takes the same place by mass as a couple or three viruses in 105 kg, in a hundred cubic meters of water — a whole water basin! Of course, the approach itself and the given calculation results are not flawless. For example, the calculations greatly underestimate the value of the M mass of the Metagalaxy, because the presence of the so-called hidden mass is not taken into account. However, even without that it is clear that the share of LM and even more so of the reasonable one is so insignificant that we have a choice: to share the opinion that Life is accidental and valuable only for the living, or to leave on some conditions for LM the prospect of performing the universal mission. The second would be possible with the adoption of the following postulate:

«Living intelligent matter can become a necessary participant in processes on a universal scale, provided that, having the necessary properties for this, it creates certain factors that are significant to the Universe»

For the sake of certainty, let’s call this postulate Vital, and the factors mentioned are the product of LM’s activity, for which the term «significant» defines something that affects the Universe as a whole. Are there any variants of such something related to living matter in the literature? Alas, there are not many. For example, here is a quote from the Wikipedia article «The Meaning of Life»: «In terms of systems analysis, all goals considered as the meaning of life form the set of all possible goals. These goals can be compared to one another, giving us the ability to rank all the goals in sequence. The goal that will have the most weight can claim to be the true meaning of life. In practice, the result of such modeling is the theory that the meaning of life is to slow down the rate of growth of entropy [6]. The question is whether this slowing down of the rate of entropy growth in lumps of living matter on insignificant (on the scale of the Universe) dust particles — planets circling their stars, which can incinerate them at the stage of red giants, turning the structured LH into a chaotic cloud of gas — is a universally significant product. It is up to the reader to judge, but it seems that the version of the product presented in this paper is more consistent with the term «meaningful to the universe». As for the term «reasonable», it is assumed that if a WB is capable of producing something of the universal level, then only if it possesses a mind. Therefore, further in the text we understand by LM only its reasonable form. It is possible to judge about the favorable period for LW activity by the works where the total time T of the Universe development is divided into epochs [7].

For the known reasons (the accumulation of constituent elements, creation of habitats, etc.), life does not arise before the so-called Age of                                                                                                                                                                                                                                         (106 Т < 1014) years.

Most likely, for the existence and activity of LMs, the current period of active star birth is the most likely time, which will end when the galaxies have exhausted all of their interstellar gas reserves. Thus, if the LM is destined to some mission, it is in the Stars Age that it will have to be fulfilled. Using the example of the Earth, it is obvious that today our civilization is not capable of influencing universal processes in any way. However, things may change in the future. Since there is no information about Intelligence outside of Earth, we will rely on available knowledge (or misconceptions) as well as logic, common sense, and the assumption based on it to predict the possibility of creating a significant product for the Universe: 

                                                                    expectedly what is demanded, permissible, and motivated.

A little about terms: 

Demanded is something that is presumed to be vital for the entire LM, but it can also be something related to the interests of a group of its representatives who have the means to achieve the desired goal. Other grounds for demand are also possible.

                                                                                                                                                                                                  Motivated — first of all, it is something conditioned by intentions and the possibility to provide financially for the creation of a demanded product. But not only that. The motive may be scientific interest, competitive spirit, curiosity, and even feelings such as hatred, envy, despair, or other passions of intelligent subjects manifested at the critical moment, depending on the type of product being created.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Permissible — anything that the known laws of nature allow. New knowledge in the future will undoubtedly change the boundaries of what is acceptable. 

Let us demonstrate this way of predicting on two examples:

Example 1. Is it possible to create a permanent human colony on Mars.

In demand? It’s not quite clear yet, but let’s assume it is.                                                                                                                                                                                                                                                                                                         Motivated? It seems so (NASA, I. Musk, Roscosmos, China, etc.). For example, in the document titled «NASA’s Plans for Exploration Beyond Low Earth Orbit», the cost of the «Martian» missions was estimated based on the Jet Propulsion Laboratory (JPL) study which foresees a manned flight to Phobos in 2033, a landing on Mars in 2037 and a one-year stay on the red planet in 2041 and 2046. According to calculations of JPL specialists, at least 430 billion dollars will have to be spent on this in 2016-2046 [8].                                                                                                                                                                                                                                                                                                                 Is it permissible? According to science as of today, apparently not. If only because there is no perceptible magnetic field on Mars, without which in half a year humans and all living things will surely have very serious problems [9].                                                                                                                                                                               Conclusion: in our opinion, taking into account this circumstance already, a colony on Mars with a long stay of people is most likely impossible.  However, with the reduction of flight time there and back, it is possible to explore Mars (as well as the Moon) on a rotational basis. Creation of a global magnetic field or its analogs is not excluded in the future. However, the very fact of creation of such colonies for the Universe as a whole is of no importance.

Example 2. Is it possible to create an artificial black hole on Earth?

There is enough information about so-called black holes (BH) in the same Wikipedia. At the modern level of understanding, a BH is an object, powerful gravitational field of which creates a surrounding surface called «horizon» and everything that crosses this boundary (even light) cannot return back and this singularity seems black. In nature, the formation of BHs is accompanied by enormous flows of energy and leads to the death of everything that falls beyond its horizon. As for artificial BHs, it is assumed that microscopic, so-called quantum BHs can arise from nuclear reactions. Recently, experiments have been proposed to find evidence of the appearance of BHs in nuclear reactions. However, for the synthesis of BHs, the currently unattainable energy ~ 1026 eV is required [10]. 

In demand? Not yet, but projects of engines, energy sources (singular reactor) and even a bomb using BH are being discussed [11]. Of course, all this is not feasible now, but specialists are actively studying this topic.                                                                                                                                                                                                                                       Permissible? Today we cannot create a BH, at least for energy reasons. And then? For example, in [12] it is allowed in the future the appearance in the center of the Earth of a safe artificial micro BH slowly gaining mass at the level of 1 kg per 1012 years, which, in principle, fits into the interval of the Stellar Age (up to 1014 years). Meanwhile, when the Sun becomes a red giant with a diameter up to the Earth’s orbit, the matter of the star will get into the event horizon, which may lead to a more rapid growth of the mass of this BH.                                                                                                                                                                                                                                                                              Motivated? Probably not today. Except as an excuse for financial machinations. What will happen next is unknown, but very likely — yes, given the inherent search 

Conclusion: In the future, a fatal BH could theoretically appear on Earth due to mistakes made in the work on the creation of BHs.             

The variant proposed in [12] says that in this case our planet will not disappear and this object will be harmless, no matter how many laws of physics we do not discover and revise. Let’s not argue and hope that it will turn out so. However, let’s note that even nuclear physics was a safe science until 1940. For example, the physicist E. Rutherford stated in a letter to the British Scientific Association in 1937 that it would never be possible to obtain nuclear energy in any significant quantities sufficient for practical use [13]. As you know, a few years later the nuclear bombing of Japanese cities proved this opinion wrong.

Of course, a fatal BH, if it leads to the destruction of our planet in the future, will not be a noticeable phenomenon on the scale of the Universe. But assuming that the development paths of the LM are more or less similar on the Earth and exoplanets, we can also expect the appearance of BHs on some of them. This is important because it is the artificial BHs that may turn out to be a meaningful product for the Universe, unavailable (fortunately!) to us today, but which may be produced by more advanced civilizations outside Earth if for some reason [14], the created BHs, like their natural analogues, will absorb the matter within the event horizon, unlimitedly  increasing the mass of this kind of objects. Recall that after the Stellar Age and the following Age of Decay, as it is believed, will come the Black Hole Age [8]                         

                                                                  (1040  <  Т < 10100) years

At this stage, the matter is a sea of elementary particles and BHs come to the fore. The conditions (mainly, mass), under which the final state of star evolution is a BH, are not well studied, because it is necessary to know the behavior and states of matter at extremely high densities, inaccessible for experimental study. Modeling of stars in the late stages of their evolution presents additional difficulties because of the complexity of the arising chemical composition and the sharp decrease of the characteristic time of the processes. Suffice it to mention that some cosmic catastrophes, such as supernova explosions, occur precisely at these stages of stellar evolution. Various models estimate the mass of a BH arisen from cosmic matter in a natural way from 2.5 to 5.6 solar masses. Subsequently, the BH may expand due to the absorption of matter — as a rule, it is the gas of the neighboring star in binary stellar systems. During the previous period, BHs have collected all matter on themselves, and in this epoch they only radiate. There are two main mechanisms: when BHs collide and merge, gravitational energy is released, carried away by gravitational waves. The second mechanism is the Hawking radiation [15]. Further, fundamentally different variants of development are possible for the Universe: stationary (1) and cyclic (2):

  1. BHs merging into clusters and superclusters will merge. As a result, a single stationary Giant Black Hole (GBH) with the resulting mass M appears, which will exist practically forever.
  2. Perhaps, at a certain critical mass M = M*, the GBH will reach the Planck density, under the action of gravity will heat up to the Planck temperature and will cause another Big Bang, giving rise to a new Universe [16].

    Some theories say that the Universe can shrink to the state from which it began, and then a new Big Bang will occur, and such cycles of contraction-expansion will occur forever [17], as far as the concept «forever» is applicable at all outside the space-time continuum. Recent experimental data (namely the observation of distant supernovae as objects of standard luminosity, as well as a careful study of relic radiation) lead to the conclusion that the expansion of the Universe is not slowed down by gravity, but on the contrary, is accelerated. However, due to the unknown nature of dark energy it is still possible that someday the acceleration will change the sign and cause compression [18].                                                                                                                                                                                                                                                                                      In a world without LM, all BHs arise naturally as a result of stellar collapses. Let the mass of the GBH formed at the merger of all «natural» BHs (taking into account the radiation losses at absorption) be equal to Mo. If this value is less than some critical value M*, the GBH is in stationary mode indefinitely long and the cyclic development of the Universe becomes impossible. The presence of an intelligent LM can change the situation. As noted, only in our Galaxy the probable number of Earth-type planets may be at the level of ~ 3∙108. With a similar state of affairs in 1011 of the same spiral galaxies, the number of exoplanets in the Universe would be ~ 1019. Let the subjects of civilizations create BHs on some of them. At their absorption by the BH, the mass of the latter will exceed Mo by the value m equal to the mass of all created BHs (taking into account the ray losses during capture).  If the Universe is cyclic, then, as a hypothesis, we can put forward the assumption that the mission of the LM is exactly to create the «addition» m necessary to reach the mass M of the GBH mass of the critical value M*:   

                                                                                      М = Мо + m = M*

    Let our hypothesis be true and Life arose (no matter where, when, or how) to that a part of its intelligent form produced a mass of BHs and died. Since everything in the Universe has a set of properties corresponding to its purpose (e.g., for the electron this is mass, charge, spin, etc.), objects of LM must also be observed characteristic features to fulfill this role. Having detected these features in representatives of one civilization (for example, ours), we assume their presence in other, if not all, representatives of intelligent LW. This is how we deal with other objects of the Universe, say, the same electrons, whose properties, measured on the Earth, are assumed to be the same everywhere for all these particles.

    By the way, this approach to biogenic (living or created by living organisms) and abiogenic (products of cosmic matter) objects from common positions is demonstrated by the science of cenology [19], created by Prof. B.Kudrin (1934-2020), the subject of its studies being cenosis-systems of elements with hyperbolic distribution of any attribute. From the point of view of this science A.S. Pushkin’s «Eugene Onegin» and the elliptical galaxy are one and the same — cenosis. The only difference is that the former is a biogenic linguocenosis with a hyperbolic distribution of words by frequency of use [20], and the latter is an abiogenic astrocenosis with the same distribution of stars by luminosity [21].

     Of this kind of expected qualities of the LM, most likely, the main one is the ultimate ability to adapt under any conditions and evolve towards the formation on their planet of the basis for the creation of the BHs — an advanced civilization, which is actually happening, for example, on the Earth [22]. In a number of publications it is also possible to identify the properties, in our opinion, necessary for an intelligent LM to create a BH. In a number of publications we can also identify the properties that we believe are necessary for a reasonable LM to create a BH.For example, the article: «Megastructures of the Future: Dyson’s Sphere, Stellar Engine and «Black Hole Bomb» [23]. Quote:«Black holes can be rightfully called the largest accumulators of energy in the Universe. It is true that today it is impossible to get this energy, because a black hole is not just an accumulator, but a vacuum cleaner that absorbs everything around it. And yet there is the idea of creating a mega-building, which, in theory, would allow to extract gigantic amounts of energy from a black hole. The nuance is that because of this mega structure the BH turns into a bomb of colossal power, which can explode in case of an error». 

    To carry out such global undertakings, the objects of the LM must be characterized by an observable (for example, among us) capacity for collective work involving both leaders and ordinary workers with a certain and, it should be said, known (approximately 1:20) ratio of the number of objects of these categories [24].  This applies both to the sphere of production, scientific development, and other types of activity. 

    Most likely, the tact, intelligence, and prudence of Mind carriers suitable for ordinary collective work is not enough to create a fatal BH. Here it is «useful» (for the Universe) that some LM objects possess such habitual character traits as negligence, authoritarianism, vindictiveness, headstrongness, vindictiveness, envy, etc. On the one hand, such qualities inherent to a certain part of the team members lower the cumulative creative potential necessary for working with the BHs. On the other hand, a dosed number of carriers of negative traits promotes the creation of «necessary» (again, for the Universe) shades of intolerance and anger, encourages the desire to give a damn about everything, to outwit someone, to get the most, to achieve the impossible at any cost, etc. This encourages risky action at the limit of possibilities, as well as pissing off «normal» sentient beings, dulling the sense of danger and increasing the chances of making mistakes in the work of creating BHs. Emotional lability is also «appropriate», so that in an unhealthy environment of misunderstanding and anger, some «reasonable» people, brought to their inherent forms of insanity, lose their heads (or their analogues) and, exclaiming in their language something like, «Burn everything to the ground!», turn on switches that would cause BH to appear and destroy their planets. Of course, the enumerated properties of LM related to the creation of BH are nothing more than a starting list, which should be expanded with further work in this direction. Finally, we believe that the observability of the noted features and the fact that only a certain fraction, about 13% of LM objects, at least on Earth [24,25], are endowed with negative features speaks, rather, in favor of our hypothesis about the possible role of LM in the Universe. 

    In the categories of Good and Evil in a simple domestic interpretation [26], the creation of a BH for sentient beings is undoubtedly the result of the forces of Evil that caused the planet’s demise. On the contrary, leaving the variant without creation of BH, living objects will consider as manifestation of the forces of Good and prudence. If in order to create the «necessary» mass of m artificial BH, some civilizations must still suffer a fatal fate, then by comparing the numbers of dead NM  and surviving NV worlds, we can (in the same interpretation) estimate the ratio χ  of Good and Evil factors:

                                                                                        χ  = NM / NV ,

    immanent Universe, which we cannot change. In the future, based on the features of the corresponding models, specialists (astronomers, physicists, cosmologists, etc.) will be able to estimate the values of m and χ, corresponding to the stationary and cyclical variants of the Universe development. Taking into account the expectedly important role of living sentient objects with a «negative» character in creating fatal BHs, it can be assumed that the share of dead civilizations will be in the same measure as the noted 13 % of conditionally «evil» Mind carriers known, for example, in our society [24]. Moreover, maybe the 13% itself is due to the presence of χ and is one of the important characteristics of a reasonable LM designed to create a BH. 

    If the above stated somehow corresponds to reality, then catastrophes related to work on creation of BHs occurred, occur now and will occur in the future, and those engaged in this dangerous business somewhere have already committed fatal mistakes, and someone is ready to commit them. And this must be repeated, alas, constantly in the vastness of the Universe where otherwise the «necessary» mass of artificial BHs will not appear. 

    Conclusion: as of today, of all that Life is theoretically capable of producing, only black holes created by living sentient beings can become a product of significance for the Universe as a whole.  Therefore, in answer to the question:

                                                                     «Why might the Universe «need» Living Matter?»

    we say:

    «According to current views, if the Universe «needs» living matter, it is for a certain part of its intelligent form to create black holes, the cumulative mass of which will direct the future dynamics of the Universe according to its scenario of development». 

    Civilizations with out-of-control black holes, being absorbed by them, will undoubtedly disappear. We do not know their number, but judging by the well-known phenomenon «Fermi’s Paradox», associated with the so-called silence of the Universe [27], their number may be quite large. However, this should not scare us, but rather alert us, forcing us to responsibly treat and control thematic research and development related to the possibility of artificial black holes. 

    The proposed hypothesis about participation of reasonable beings in creation of black holes, is a particular case of the general hypothesis about a possible role of LM. Let any scenario of development of the Universe containing LW depends on the total key factor F, which value F* is a condition of realization of this scenario.   Let, similarly, in the Universe without LW, the value of F is not capable of exceeding the value Fo < F*. The general hypothesis of the assignment of LW is taken as:

     

    «In a Universe containing LM, where any variant of development requires the key factor F to have a value of F* and where without LM its value does not exceed Fo < F*, the mission of LM is to create a product — the substance of factor F in the quantity f = F*- Fo necessary to achieve this factor’s value F*».

    In the special case of our hypothesis — to consider the role for LM to create a BHs, the key factor F is the mass M of the GBH, leading at M = M*, to the cyclic character of the Universe development, in which without LM the value of this factor does not exceed Mo < M*.

    As of today, living intelligent matter is theoretically capable of producing only such a product as artificial BH, the mass of which m = M* — Mo is «necessary» for the realization of the character of the Universe development. Let tomorrow a candidate for this role will be something else, let us estimate a new factor F within the framework of the previously accepted general hypothesis and already known to us Vital postulate:

     

    «Living intelligent matter can become a necessary participant in processes on a universal scale, provided that, having the necessary properties for this, it creates certain factors that are significant to the Universe»

    It may seem bold, but by revealing a possible common goal of existence for all forms of Intelligence in the Universe, these statements bring together the fates of civilizations separated by monstrous distances that make it difficult to find jointly non-fatal (without catastrophic BHs) solutions to, say, the same energy problems. Perhaps the communication of intelligent beings could reduce the proportion of worlds killed by CHs, but it must be no coincidence that the low density of matter (much less living!) in the Universe, reduces the probability of such contacts that can deviate the values of m and χ from the «optimal» values corresponding to the dynamics inherent in the Universe. Finally, these statements can serve as a basis in the search for the properties of LM necessary both for the creation factors meaningful for the Universe and for the explanation of the features caused by these properties available in the structures and forms of civilizational development, and possibly for the prediction of their changes both in our world and in other worlds.                                                    

                                                                           Literature.

    1. The Many Faces of the Universe by Andrei Dmitrievich Linde, Stanford University (USA), Wikipedia.
    2. Habitable Exoplanets Catalog. Planetary Habitability Laboratory (5 October 2020).
    3. Report in «How many habitable planets are out there?» by SETI Institute on 10/29/2020.
    4. § 45. The biosphere and its structure — General Biology: a textbook for 11th grade.
    5. Kononovich E.V., Moroz V.I. General course of astronomy. — 2nd, revised. — URSS, 2004. — С. 468-486. — 544 с.
    6. 6. 15. Vidal, C.The Beginning and the End: The Meaning of Life in a Cosmological Perspective. — Springer, 2014.
    7. 7. Fred Adams, Gerg Laughlin. The five ages of the Universe: inside the physics of enternity. — Izhevsk: Research Center «Regular and Chaotic Dynamics», 2006. — P. 22. — 280 p.
    8. Julia Korovsky (by https://oig.nasa.gov/audits/reports/FY17/IG-17-017.pdf, https://arstechnica.co.uk/science/2017/04/the-journey-to-mars-has-a-price-tag-and-it-will-give-congress-sticker-shock
    9. Kopanev V. P., Shakura A. V. (in Russian). Influence of hypogeomagnetic field on biological objects. «Nauka, 1985. С. 17-24.
    10. В. А. Березин. О квантовом гравитационном коллапсе и квантовых чёрных дырах. — Раздел 2.4. Квантованный спектр масс// Физика элементарных частиц и атомного ядра— 2003.  Т. 34, вып. 7. — С. 48—111.

    11.William H.; Teukolsky, Sol A. (1972). «Floating orbits, Superradiation scattering and the black hole bomb». Nature. 238 (5361): 211-212.

    1. Hel I. Could the LHC create an Earth-destroying black hole? Wikipedia.
    2. Feigin O.O. Chain reaction [The unknown history of the creation of the atomic bomb]. Wikipedia.
    3. L. Crane. Possible Implications of the Quantum Theory of ravity .1994.
    4. 15. Stephen Hawking. A Brief History of Time. — Bantam Books, 1988.
    5. J. Steinhardt, N. Turok, «The Cyclical Model of the Universe.» Science,2001, 296 (5572):1436-1439.
    6. Biological Encyclopedic Dictionary / Edited by M. S. Gilyarov; Editors: A. A. Bayev, G. G. Winberg, G. A. Zavarzin et al. — M.: Soviet Encyclopedia,1986, p 10.
    7. Jennifer Bergman, The Big Crunch, Windows to the Universe (2003). 
  1. Kudrin B.I. My Seven Differences from Zipf // General and Applied Pricing. — 2007. — № 4. — С. 25-33.
  2. Kudrin B.I. 17 Lectures on General and Applied Pricing. Lecture 5. Non-Gaussianity of hyperbolic H-distributions. See Table, item 3. www.kudrinbi.ru.
  3. Gurina R.V. Cosmic systems as astrocenoses/ Pricing modeling: theoretical foundations and practical results. Proceedings of the XVth Conference on Philosophy of Technology and Techniques and the Seminar on Pricing. Vol. 47. «Pricing Studies.» — Moscow: Technetica, 2011. — С. 178-185.
  4. Y Wang, J M Kratochvil, A Linde, and M Shmakova, Current Observational Constraints on Cosmic Doomsday. JCAP 0412 (2004) 006.
  5. William H.; Teukolsky, Sol A. (1972). «Floating orbits, Superradiation scattering and the black hole bomb». Nature. 238 (5361): 211-212.
  6. 2 Lippitt, Ronald; White, Ralph. Patterns of aggressive behavior in experimentally created social climates. Journal of Social Psychology journal. — 1939. — P. 271-301.
  7. Ervin Staub Overcoming evil: genocide, violent conflict, and terrorism. New York, New York, USA: Oxford University Press, Pp. 32. (Wikipedia).
  8. Good and Evil: Sociological Aspects. Agency Research, Wikipedia. 05.09.2013.
  9. Bilenkin D. A. Why is the cosmos silent? : Reflections of a science fiction writer // Yunost. — 1982. — № 3. — С. 104-108.