For decades, humanity has been obsessed with the thought that we are not alone in this vast universe. There have been heated debates, movies, and books based on this one idea. And while there are many who say that there is no such thing as an “alien civilization,” we have continued to dream and imagine a universe filled with extraterrestrial life. 

The Milky Way galaxy is roughly 13.61 billion years old and likely has more than 200 billion stars and even more planets. Even if a ridiculously small fraction of the planets in the Milky Way have intelligent life, then our galaxy would probably be full of advanced, space-faring civilizations. If we plug in the numbers in a real mathematical formula called The Drake Equation, which is meant to estimate the number of active, communicative extraterrestrial civilizations in the universe, we arrive at a similar conclusion. 

But this makes no sense! If it is statistically almost certain that there is intelligent life in our galaxy, why haven’t we found any signs of them? Why haven’t we received any broadcasts from their home planet in the decades that we’ve been searching for them? This is a very well-known discrepancy in the scientific community called the Fermi Paradox.

One common theory that answers the Fermi Paradox is The Great Filter. According to this theory, as a species progresses, it faces “evolutionary filters.” Think of it like a level in a video game that is hard to pass, but you need to get by it to keep going in the game. But The Great Filter is no ordinary level or filter. It is a level that every species needs to pass. If it doesn't, it stops moving forward and might even go extinct.

Now there are two possibilities for humans within this theory: either The Great Filter is behind us, or it is ahead of us. Behind us would mean that we have already passed this key checkpoint as we evolved over the years. But perhaps other intelligent lifeforms in our galaxy didn’t have the same luck and went extinct. Maybe life does pop up everywhere in the galaxy but goes extinct because of this evolutionary barrier. 

On the other hand, however, there is a possibility that The Great Filter is ahead of us, still in the future, meaning we have yet to encounter this evolutionary barrier. Perhaps there were multiple intelligent, civilized lifeforms before us, but they all got "filtered out." Maybe we’re next on the chopping block. 

Another popular answer to the Fermi Paradox is a theory called The Dark Forest, which holds that we shouldn’t be looking around the universe for aliens: every civilization wants to survive, and maybe it’s in their best interest to attack us before we could attack them. Maybe it is in our best interests to attack them. No side really knows the other side’s intentions, especially with the language- and huge-distance-barriers. So it might be best to be the first one to press the “big red button” first and demolish your neighbors. Think of the Milky Way as a dark forest, and think of every civilization as a hunter. Each hunter has no idea what the other hunters’ intentions are, so it's probably best to avoid detection. This analogy is dark, but it could capture what's going on in our galaxy.

Another variation of this theory is that maybe there are a lot of home-bound civilizations like us who are just hiding from one big one. Maybe there is one dominant civilization in our galaxy that steals resources from others. Maybe if we bring attention to ourselves, they will notice us, come to us, and steal our resources to feed their massive, advanced civilization.

But right now, all we really know is that we are not ready to pick a fight with an interstellar civilization. After all, compared to them, we might as well be toddlers who are still learning the ways of the universe. 

Speaking of toddlers, who often like zoos, another theory to answer the Fermi Paradox is The Zoo: basically, aliens aren’t interested in us. 

Imagine you go to the zoo. You are walking by habitats with animals in them. Now imagine you stop in front of the chimpanzee habitat. You are intrigued by what the chimpanzee is doing and how it’s climbing the tree, but would you try verbally communicating with it? Would you try asking it how its day is going? What its name is? Let’s be honest, you probably wouldn’t. Because you know that the chimpanzee cannot intelligently respond to you or even understand you at a basic level. You know that the chimpanzee is less advanced than you. Now think about this on a civilizational scale.

Now you might be wondering, how can you compare how advanced different civilizations are? Well, there is a real scientific scale developed for this exact purpose. In 1964, the Kardashev Scale was developed by Soviet astronomer Nikolai Kardashev. Its goal is to measure the technological advancement of a civilization by the amount of energy it is capable of harnessing. There are four main levels: a Type I civilization is capable of fully harnessing the energy of its planet. A Type II civilization is capable of fully harnessing the energy of its solar system. A Type III civilization is capable of fully harnessing the energy of its galaxy. A Type IV civilization is capable of fully harnessing the energy of its own supercluster of galaxies and possibly its universe. Now you might be wondering where we humans are. Well, we are a Type 0.7276 civilization. Yes, that’s right, we aren’t even a Type I civilization. That’s because we still haven’t learned how to fully harness the energy of our planet. But we are working towards it.

But now that we understand the Kardashev Scale, let’s look back to our original question. If a Type III civilization decided to go for a stroll in their galaxy, would they be interested in us? After all, we aren’t even a Type I civilization. What would be the purpose of a Type III communicating with us? We likely wouldn’t even be able to understand them. And even if we could, they would probably be too advanced for us to understand. And our ape brains could be fried beyond repair. Forget chimpanzees! In this scenario, we are ants or maybe less, and the Type III civilization is the human. There is simply no point for a Type III civilization to even attempt to communicate with us or show us signs that they exist. 

Yet another way to think about all this is that maybe we are being watched over by a committee of aliens. Maybe these aliens know that we are not even close to being advanced enough to understand them, and for that reason, they haven’t showed us any signs that they exist. They are just waiting for us to evolve and catch up to them. 

Obviously, these are not the only theories to answer the Fermi Paradox, but they are some of the most popular ones. While these are great theories and fun to ponder, there is no certainty that any of them are correct. And to tell the truth, we might never know. There is no guarantee that we will survive long enough to travel far enough in space to search for neighbors. Especially with what is happening in the world today.

But it doesn’t matter only what old men in lab coats who live in laboratories think. It also matters what you think.

Do you think that we should continue to search for aliens? Do you think that we are in the universe by ourselves? Take this short, anonymous poll. The Acta Diurna will report on the results soon.