image: Fantastic Planet (1973 Sci-fi/Animation film)

Video: The Fermi Paradox - Where Are All The Aliens? (1/2) (Kurzgesagt)

 

 

The growing understanding of astronomy has elicited a heated philosophical debate regarding the existence of extraterrestrial civilisations. Throughout the essay, I will aim to defend my contention that there are no good reasons to conclusively believe that the absence of extraterrestrial civilisation would be bad news. Prior to defending this view, it is essential to outline how the extraterrestrial life debate was developed and later I shall explain why the absence of extra-terrestrial intelligence is arguably existentially troubling as opposed to being an 'up-side'.

 

The questions surrounding extra-terrestrial civilisation were raised, but appreciated more seriously as Stephen Gillett reflected on the problem Enrico Fermi identified. The age of the universe is remarkably old, and its size is vastly huge with billions of stars in the Milky Way alone. Thus, it is peculiar to not think that there should be millions of extraterrestrial civilisations possibly in billions of years in advance of us. It is worth considering here Nikolai Kardashev's tripartite classification of extraterrestrial civilisations on the grounds of technology. "The first is the Kardashev type 1 civilisation which is comparable to our own, and could employ the resources of a planet. The second is Kardashev type 2 civilisation, and this type of civilisation could employ the energy resources of a star. Finally, others can be classified as Kardashev type 3 civilisation, which could employ the energy resources of an entire galaxy" (Webb, 2015: 1-2). According to modern science, the age of the galaxy is remarkably old, and it is highly likely that there will be millions of extraterrestrial civilisations. Similar to how Kardashev suggested that extraterrestrial civilisations would be advanced, they could be a billion years in advance of us on the grounds of technology. Here, Gillett suggests that from what we can learn from terrestrial life is that "it has a natural tendency to expand into all available space" (ibid., 2). It is true that let alone human beings have expanded to space, sending probes or establishing international space stations (Bostrom, 2008). Gillett reasons that if extraterrestrial life behaves in a similar way to life here on Earth, the galaxy or several numbers of galaxies should already have been colonised by a KII or KIII civilisations (Webb, 2015:2). Here, Gillett raises Fermi's paradox as he states "they should already be here, and yet we do not see any evidence that extraterrestrial civilisations exist" (ibid.). Gillett points out that the apparent absence of extraterrestrial intelligence leads us to one conclusion, namely, that human beings are alone in the universe. For some philosophers of the future, there cannot be an 'up-side' should we accept this conclusion. There is one subsequent question that needs to be answered as well, as we outline the reasons for the proponents to hold this view, which is why the gigantic and old space is apparently empty of any other civilisations.

 

Concerning this, one of the things that is worth considering here is our recent discovery of potential proof of extraterrestrial life, fossilised Martian microbes discovered in meteorite ALH84001 from Antarctica, for example. One of the implications of finding evidence for extraterrestrial life as such, Bostrom suggests, is that the Great Filter is not likely to occur in the early life of planets and there are more Filters to come for any lives on planets. This would entail that we are not rare in managing to surpass the existential cataclysm in the early developmental stage of lives on any planet. Additionally, as Bostrom posits, if we found evidence for a more complex life-from than us, and this scenario would also suggest that the Great Filter lies ahead of us. Since our universe is incredibly old and huge in its size, it should be filled with advanced extraterrestrial civilisations conquering galaxies. Yet, we cannot observe any sign of intelligent lives in the universe other than us. The evidence for extraterrestrial simple lives or animals would entail that the conditions for life in the universe are not as rare or difficult as some posit. This, however, will entail that the conditions for KII or KIII technology are incredibly rare or impossible. This would explain the Great Silence as to why we might detect signs of early life in developments on those other planets. Simply, they cannot surpass the Great Filter- specifically the Filter that lies between civilisations of our level, and the K1, K2, and KIIIs, since there are early Filters as well. This means that our terrestrial life will also have to encounter a possible catastrophic event that could potentially bar us from civilisations becoming KII or KIII civilisations, possibly eliminating us the moment we encounter it. Then, for any advanced extraterrestrial civilisations of KII or KIII kinds, they must have survived the aforementioned existential risks. Yet, we have not encountered any extraterrestrial civilisations of such kinds, which suggests that either we have always been the only intelligent life living amongst other billions of planets since the beginning of the universe. Alternatively, there could have existed extraterrestrial civilisation even before life emerged on our planet, but they could not survive through the Great Filter which we will eventually have to encounter. The question we should ask then is where in the stage of development of life, is this existential cataclysm- the Great Filter positioned? 

 

When we constitute an effective Great Filter, for any civilisation, there has to be an existential risk that not only applies to humankind but on a universal basis. There have been many suggestions but in particular, Bostrom states that the most likely universal Great Filter kind would be those that arise from technological discovery, of whose "adverse outcome would annihilate Earth-originating intelligent life or permanently and drastically curtail its potential for future development, which would include a nuclear war, a genetically engineered superbug", or similar to such kinds (Bostrom, 2008:7). This potentially explains the Great Silence as to why we have not heard from extraterrestrial civilisations yet. It is because namely, all the other civilisations failed to survive the aforementioned adverse outcomes of the technological discovery. I agree with Bostrom that we are no exception from encountering the devastating event that no other civilisations survived. Given that this is true, we must expect that our own terrestrial lives should go extinct before even reaching technological maturity for space colonisation (Bostrom, 2008). For this reason, the absence of extraterrestrial civilisations would arguably be bad news.

 

Whilst it seems convincing that the absence of extraterrestrial civilisation would be bad news, we should consider other reasons for the Great Silence. One possible reason includes that all extraterrestrial civilisations are purposefully keeping themselves quiet once they became KII or KIII civilisations. In one of the science fiction novels written by Liu Cixin, the Dark Forest- an argument for this view can be identified. "Firstly, all life desires to stay alive. Secondly, there is no way to know if other lifeforms can or will destroy you if given a chance. Given that this is true, the safest option for any species is to annihilate other life forms before they have a chance to do the same" (Hendricks, 2018). This should also be able to explain the Great Silence that we have not received any radio signals in reply. As Hendricks explains, other civilisations are so fearful of being detected that they purposely avoid sending out any radio evidence of their existence which would lead them to their annihilation (ibid.).

 

Given that this is true, we are perhaps not in the existential risk as the way Bostrom describes we are in. There are billions of civilisations which surpassed the Great Filter to acquire the technology to colonise other planets, but they are just risk-averse from other conquering civilisations. Regarding this, something that is worth noting is that we lack our understanding of extraterrestrial civilisations. However, what we can gather from human history is that, as Stephen Hawking puts it in one of his interviews, "contact between humans and less intelligent organisms have often been disastrous from their point of view, and encounters between civilisations with advanced versus primitive technologies have gone badly for the less advanced" (Cofiled, 2015). Thus, we might possibly argue that the apparent absence of extra-terrestrial intelligence is good news since it would be existentially dangerous for us to hear from the civilisation of KII or KIII type to receive our signals and identify our locations to expand their colonies. However, we should note that this is one of the possibilities that could take place. As Hendricks is aware of the same issue here, we cannot assume that other extraterrestrial civilisations have a reasoning process as we do. Perhaps the premise behind the Kardashev classification is wrong in the first place. Extraterrestrial civilisations could be more peaceful than human beings have been throughout our history.

 

Indeed, we cannot extrapolate our experience of living on this planet in particular to other extraterrestrial civilisations, since the conditions for evolution given to other intelligent lives will differ from ours.. What seems reasonable to apply is the notion of natural selection. Trefil and Summers explain this through the analogy of two hikers running from a hungry bear. They state that it does not make any difference if the runner is a kind man who helps old ladies across the street (Trefil and Summers, 2019). The only thing that natural selection is interested in is that for the sake of survival, they should be stronger than other civilisations in colonial wars to survive from scarce resources in their territories. This, however, does not seem applicable when we consider the case that the extraterrestrial lives are of KII or KIII-type civilisations. Jill Tarter, former director of the Centre for SETI, states, they might not even be in the need for enslaving another civilisation. For if they would visit Earth, they would have "technological capabilities sophisticated enough not to need slaves, food or other planets" (Cofield, 2015). Looking for resources, given that they have highly sophisticated technology to generate to supply their resources, seems unlikely. Yet, this does not entail that we are not subject to existential annihilation from alien attacks. Choosing not to destroy means they are still able to destroy us at any minute.

 

We have seen how the extraterrestrial life debate was developed and why the absence of extraterrestrial intelligence is arguably existentially troubling. The proponents of this assessment claim that we would face the existential threat other extraterrestrial civilisations faced before they reached the next level of intelligence. The Great Silence entails one of the possibilities that they did not surpass the Great Filter. Equally, we can consider the case that another extraterrestrial civilisation is choosing to be silent to survive from superior civilisation. Thus, the apparent absence of extraterrestrial intelligence is arguably good news. It seems we do not have good reasons to conclusively believe in the aforementioned assessment above yet. However, given that extraterrestrial civilisations exist, for the sake of avoiding potential existential threats, the best existential strategy for us to do in this case is to either stop sending signals or to show them we are of sophisticated Kardashev-type. This will lead them to avoid sending signals of any kind as a reply for the sake of their survival. Until then, we keep on developing in the hope that we can reach the next level of intelligence.

 

 

*Retrospective thoughts on this essay:

 

I suggested towards the end that there might be some very high-level civilisations that aren't interested in colonising or exploring, but who are also keen not to show themselves to the rest of the universe. This may well be true. However, in the Dark Forest scenario, there's an obstacle: the deadly probes could be lurking in each solar system, watching and waiting - so even if a society decides to remain discrete, they could still be detected and eliminated...

 

Bibliography

 

Bostrom, N (2008) 'Where are they? Why I hope the search for existential life finds nothing', Technology Review (Cambridge, Mass), p.72-77.

 

Cofield, C. (2015). Stephen Hawking: Intelligent Aliens Could Destroy Humanity, But Let's Search Anyway. [online] Space.com. Available at: www.space.com/29999-stephen-hawking-intelligent-alien-life-danger.html [Accessed 7 Mar. 2020].

 

Hendricks, S. (2018) Dark Forest theory: A terrifying explanation of why we haven't heard from aliens yet. [online] Available at: https://bigthink.com/scotty-hendricks/the-dark-forest-theory-a-terrifying-explanation-of-why-we-havent-heard-from-aliens-yet [Accessed 5 Mar. 2020].

 

Trefil, J. and Summers, M., 2019. If Aliens Existed Elsewhere In The Universe, How Would They Behave? [online] Smithsonian Magazine.

 

Webb, S. (2015) If the Universe is Teeming with Aliens... Where is Everybody? Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life. 2nd ed. 2015 Springer International Publishing (Science and Fiction).