Aliens. They’ve been the subject of scientific interest and a regular subject of science fiction writings. They’ve dominated our minds and have been at the forefront of our imaginations for centuries now. They’re central characters in several conspiracy theories, but the biggest question about them is still the most fundamental one, something we have failed to answer after all our years of scientific advancement – Do Aliens Really Exist?
This question may seem to have a simple yes or no answer, and it probably will, when the answer is discovered. However, it is the ramifications of this answer that we really should focus on, and today, I’ll explore and put forward the various viewpoints that I have on this subject.
What We Know So Far
Honestly, not much. There is no hard evidence to prove that Aliens exist, but this absence of conclusive evidence can also not lead us to believe that Aliens don’t exist. The Universe, after all, is a massive playground, and we haven’t even discovered 1% of it.
But let’s give our discussion here some perspective. Our Solar System is a very average one, it has one star, with eight planets revolving around it. For every grain of sand on our planet, there are about 10,000 stars in the Universe. To be more precise, kind of, there are about 1022 – 1024 stars. Let’s say 5% of those are like our Sun. That leaves 500 Billion Billion Sun-like stars. Let one in every five of those have a planet in the Goldilocks Zone*, then we have 100 Billion Billion Earth-like planets. Out of these, let’s say 1% of these have life show up. Then every grain of sand would represent an Earth-like exoplanet with life on it. If we use this estimation to our galaxy, then we can say that there are around 100,000 to 1 million planets that can potentially have intelligent life on them.
Yet, after years of research and attempting contact, we’ve heard back from exactly………… zero. So the big question, where is everyone?
The Drake Equation
Before we ask where everyone is, a more relevant question would be to ask if there is an “everyone”. What if we truly are alone? What if there are no Aliens out there? What if, somehow, we are the only life forms in the entire Universe?
These questions, however intriguing, do not seem to have a positive answer, as our assumptions in the above section would show. We surely can’t be alone in the Milky Way Galaxy, let alone the Universe. The concept that we are special in our existence has been proven wrong time and again, and if history is anything to go by, we won’t be proven to be special this time either.
American astrophysicist Frank Drake believed in the same philosophy, and first proposed the Drake Equation in the first meeting of SETI (Search for Extraterrestrial Intelligence). The Drake Equation consists of seven terms which when multiplied together give a probabilistic number that represents the number of Extraterrestrial Civilizations that exist.
Where,
N = number of civilizations that can exist
R* = the avg rate of star formation every year - this term is what we're most certain of
Fp = fraction of those stars that have planets - 10 - 50 % of stars have planets
Ne = average number of planets that could support life
Fl = fraction of planets that develop life at some point
Fi = fraction of planets that go on to develop intelligent life
Fc = fraction of civilizations that develop technology that can be detected.
L = How long a civilization lasts
As we can see from the above description, most of the terms are highly conjectural, and the latter terms such as Fl or Fc are seemingly impossible to calculate. The last few terms are almost always educated guesses at best, leaving any final answer up to how optimistic or pessimistic you are about the future. However, the equation does give us a crude picture of how many civilizations might exist. An interesting thing about the equation is that even if one of those terms becomes zero, that’s it. The number N reduces to zero, and we’re all alone in the Universe. This does indicate that the phenomenon of intelligent life surviving over a long period of time can be very rare, and consequently very hard to detect.
But even this equation doesn’t provide reasoning as to why we haven’t heard back from anyone yet. Looking at it more objectively, our search for extraterrestrial life is based on the assumption that they use technology similar to ours. We send out radio waves into deep space, spacecraft such as the Voyager Missions and try and detect biochemical compositions of exo-planets to see if life exists elsewhere. But what if Aliens do not communicate like us? Come to think of it, of all the life on Earth, how many other species actually have a verbal means of communication? And how many of them do we understand? These questions are not only just extremely important, but pose the fundamental question of how do we communicate with any other intelligent life, if it exists.
Another important thing to consider is the duration of time since we’ve been doing this. For all the time we’ve existed, humans have looked up to the sky and wondered what was up there. But it wasn’t until very recently that we started sending out radio waves into space, in fact, we’ve only been doing so for the past 100 years or so. Compare this to the time the Human Civilization has existed on Earth. This same argument goes to show that it’s entirely possible that life is out there, just that they can’t detect it yet. We’ve been around 50,000 odd years and we could detect these radio waves for only the past 100, what’re the odds of our signals being detected so fast?
All this conjecture misses one of the most significant terms in Drake’s Equation, L. The time a civilization exists before it’s too late. See, our Universe is 13.8 Billion years old. The Earth has been around for only 4.3 Billion years. Even before the Earth was formed, there were about 5 Billion years where entire civilizations could have risen, evolved, reached their zenith and been destroyed. Yet, today, we see absolutely nothing. ‘L’ is an extremely important term in our discussion. The fact that it exists tells us that it must be finite, which means that every civilization does die out at some point. This brings us to the next major topic, The Great Filter.
The Great Filter
So we’ve established that there’s a timeline to our existence. We have evolved as a species and have overcome challenges in the past to reach our current state as a civilization. The Great Filter theory says exactly this, each civilization must overcome different hurdles at different points in time to progress and survive. There can be many such evolutionary hurdles that civilizations encounter. The first could be to develop multi-cellular life. Maybe that’s an easy one. The next could be to develop a verbal form of communication. The next could be to understand some basic technology. However, each of these steps becomes increasingly challenging, and there comes a point where it becomes extremely difficult to cross. The question here is, have we already crossed this Great Filter, or does it lie ahead of us?
Given the age of our galaxy, by this time, it is entirely possible that a Type 3 civilization would have come into existence(The next sections explains this in detail). Now, that civilization would’ve had to cross this barrier to become the galactic civilization it is, in order to be able to colonize the resources of the galaxy. However, we see nothing of the sort. So if the Great Filter is behind us, then good, we’ve crossed an almost impossible step and become one of the few, if not the first advanced civilization in the Universe. But if it’s in front of us, well…….. that’s not good news.
In the future, if we do detect an advanced alien civilization that died out in the process of trying to cross the Great Filter, we’ll know that it is in front of us. But we also know that if this is the case, then almost every civilization that encounters this filter is destroyed by it, simply because we haven’t. This isn’t a case where a majority of a civilization is destroyed, no, this challenge destroys 100% of everything that encounters it. Therefore if we fail at this, it’s lights out for us, and not in a pretty way.
So what could this Great Filter be?
The Kardashev Scale
The Kardashev Scale was given by Soviet astronomer Nikolai Kardashev. It’s a scale to measure the technological progress of any given civilization based on the amount of energy it is able to use.
A Type I civilization also called a planetary civilization—can use and store all of the energy available on its planet.
A Type II civilization also called a stellar civilization—can use and control energy at the scale of its stellar system.
A Type III civilization also called a galactic civilization—can control energy at the scale of its entire host galaxy.
As of now, we are somewhere close to 0.73 on this scale, and our close to achieving Type I status in the coming future. However, transitioning into a Type II civilization could take a very, very long time, and there is no saying as to whether it’s even possible. But given this scale of measurement, what if there already are other civilizations that have achieved a higher status than us?
In that case, they’ve probably already detected us. They know we’re out here and they’re actively choosing not to make contact with us. This could be for a variety of reasons, maybe we’re too primitive, maybe we’re too out of the way and there’s just no point in spending expensive resources to come and make contact.
But then, there’s the possibility that they know we’re here, and that they’re simply monitoring us. This would make sense for a Type III civilization. If they do exist, maybe they’re allowing us to grow, studying our progress. We could be their little science experiment, just at a Galactic Scale. This could be very dangerous for us. If history is anything to go by, whenever a stronger species has come across a weaker one, the confrontation has never ended well for the latter. Take Homo Sapiens against Neanderthals as an example. Or more recently, the colonization of South American countries by Spanish Conquistadors, or even North America by Britain.
We are now trying to build and develop AGI, or Artificial General Intelligence, a version of AI that is by far the smartest creation we’ll ever create. It will represent the pinnacle of Human Technology, us at our very greatest. What if, when we do detect any advanced Alien life, this AGI deems it to be a threat and tries to attack it? It will, in all probability, fail, and that is the worst possible thing that could happen to us.
When a civilization with the power to colonize the entire galaxy decides to flip the off switch on its experiment, we stand no chance. And maybe this is the Great Filter. Maybe there does exist an all-powerful civilization out there that’s simply waiting for us to reach that tipping point where it’s just not fun to watch us grow anymore.
First contact with Alien life will be the most dangerous thing Humanity would have faced in all its existence. One wrong step and we would literally be hammering the nails on our own coffin. And given this knowledge, it isn’t unreasonable to suggest that if we do ever receive signals from an Alien civilization, maybe we do not respond back. Maybe we detect them and stay silent. Maybe we just play dead, and let them tell us everything about them because that is what we’ve been doing all this time.
We’ve been sending out information about ourselves, where to find us, our culture, our languages, our science, our knowledge, we’ve given any civilization studying everything it needs. We’re so desperate to not be alone that we haven’t even considered the consequences of us not being alone.
How we approach this debate is up to every individual. The excitement of knowing that Alien civilizations exists excites the scientific part of me, but the realist in me tells me that this isn’t the safest option. Whatever happens, if the Great Filter is ahead of us or behind us, or if there is an Alien Civilization stalking us, the term ‘L’ from Drake’s Equation remains finite, which means that there’s a clock ticking down on our time as a civilization. Are we closer to the beginning of Human Civilization or are we closer to the End? Whatever the answer is, I know that I don’t want to be around, when the clock runs out.
Glossary:
1) Goldilocks Zone: The Goldilocks Zone refers to the habitable zone around a star where the temperature is just right - not too hot and not too cold - for liquid water to exist on a planet.
2) The Great Filter: The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis, in time, to expanding lasting life as measured by the Kardashev scale. A beautiful article by Robin Hanson explains this concept in detail, check it out, The Great Filter and Hansen's List.
3) Abiogenesis: Of course this is the next word, what did you think it would be? Abiogenesis refers to the natural process of development of life from non-living matter such as natural organic compounds. Essentially, it's a theory o explain the Origin of Life.
4) The Drake Equation: I'm sure you already have had your fill of space equations for today, this point is simply a clarification. The Drake Equation, as is evident from the terms involved in it, is completely based on your point of view, and therefore can be used for nothing more than estimation. More concrete arguments for existence of Extraterrestrial Life can be made on the basis of The Great Filter, The Fermi Paradox and can be measured using the Karadashev Scale.
References:
1. curiosity.com
2. futurism.com
3. Aperture (youtube channel)
This article is just a point of view, and is of course highly debatable, something I encourage you to do. Feel free to present your views in the comment section of the respective Instagram or Facebook post on my page, I'll be glad to hear your views! However, I urge you to keep the comments respectful and non-derogatory. I hope you enjoyed the article.
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