Fermi’s Paradox: Are we Really Alone?
Written By: Vidya Sinha
A Puzzling Paradox
Fermi's paradox is best summarized with physicist Enrico Fermi’s earnest question: “but where is everybody?” It is a bewildering concept in astrobiology that questions the existence of life beyond our planet. The paradox arises from two irreconcilables: the reasonable expectation of extraterrestrial life and the confounding absence of evidence for it. The lack of contact with extraterrestrial life seems to indicate its nonexistence. But in a universe of such epic proportions, how can our planet be the sole host of living organisms? Key insights into the development of life and the optimal survival strategy for civilizations may provide an answer to this tantalizing question.
The Great Filter Theory
The Great Filter theory was first propounded by economist Robin Hanson. The premise of the theory is that there is a stage in the evolutionary progression of life that is nearly insurmountable, and it follows that it is extremely improbable for life to progress past this
stage. The theory does not make assertions about the specifics of this stage, only proposing the existence of one.
Without loss of generality, assume that this stage was the transition from unicellular to multicellular life. In this scenario, we should expect to find very few extraterrestrial life forms that have transcended this stage. Therefore, we would expect to encounter negligible traces of intelligent life. If this theory aligns with reality, intelligent life on Earth is a statistical anomaly.
Another possibility is that the great filter exists at a higher level than that of sentient terrestrial life, such as human beings, and that this level is strictly necessary to enable intergalactic space travel. If this were true, the lack of contact with extraterrestrial life would be a direct consequence of the fact that intergalactic communication and travel have not been attained by any existing civilization. An
alternative chilling possibility is that they have, but this stage of advancement coincides with self-annihilation for the vast majority of advanced civilizations; the filter would not be intergalactic travel, but rather a species’s capacity to avoid self-destruction aer a certain level of advancement.
The Dark Forest Principle
In our analysis thus far, we have ignored one crucial question: even if advanced civilizations were capable of contacting us, would they choose to do so? To answer this question, we must draw upon the dark forest principle, a corollary of decision theory.
The dark forest principle relies on the assumption that living organisms generally desire to survive. This is simply a consequence of natural selection; those who desire to survive are more likely to do so,
and conversely, we would reasonably expect the will to survive to be a prevalent trait among surviving organisms.
The dark forest principle also assumes that intergalactic communication must occur over massive lengths of time. Even if time perception is relative, and one billion years in one civilization may be the equivalent of one second in another civilization, there is no way for any civilization to assess another’s processing speed immediately. The same logic applies when accounting for external factors such as gravitational time dilation, which can fundamentally alter the passing of time. Therefore, it is reasonable to assume that the time for intergalactic transmission may be perceived by one or more of the parties involved as an extremely long delay.
The crux of the idea is that if we were to contact an intelligent civilization, we would not be able to establish a peaceful relation
within a reasonable amount of time due to these temporal constraints on communication. It follows that if the contacted civilization was hostile and inclined to destroy other civilizations, the decision to establish a diplomatic relationship would be illogical, since we could be annihilated in the communicative delay period. Thus, the most rational decision would be to attack the other civilization before they potentially attack us. This logic is symmetric; the most logical decision for both parties would be to wage intergalactic war.
It follows that existing intelligent civilizations may actively avoid contacting others to circumvent the possibility of intergalactic war. In this light, the lack of evidence for extraterrestrial life reflects the fact that an intelligent civilization with the capacity to contact us would rationally abstain from doing so. In this sense, the principle likens the
universe to a dark forest with unknown perils, where it is better to be safe than sorry, and it is prudent to impale whoever you find.
Conclusion
There are myriad other theories surrounding the Fermi paradox, but the aforementioned two are particularly powerful. The next time you gaze up at the starry night sky and ponder the existence of our galactic neighbors, keep in mind that even if you are not truly alone, it may be unwise to set out looking for trouble - you never know who you might find lurking in the underbrush, and it is impossible to distinguish friend from foe.
Works Cited
Adler, D. (2023, May 18). The Great Filter: a possible solution to the Fermi Paradox. Astronomy Magazine. https://www.astronomy.com/science/the-great-filter-a-possible-solution-to-the-fermi-paradox/
Hendricks, S. (2021, September 30). Dark Forest theory: A terrifying explanation of why we haven’t heard from aliens yet. Big Think. https://bigthink.com/surprising-science/the-dark-forest-theory-a-terrifying-explanation-of-why-we-havent-heard-from-aliens-yet/
Chace, C. (2023, January 4). The Fermi paradox: Where is everyone? Forbes. www.forbes.com%2Fsites%2Fcalumchace%2F2023%2F01%2F04%2Fthe-fermi-paradox-where-is-everyone%2F&usg=AOvVaw1W8aQCcoFzRqaAmD-5sY4X&opi=89978449
