A question that’s been perplexing me and every man that’s ever wondered about life elsewhere in the universe for a long time now. A few years ago, I stumbled upon Fermi’s Paradox and spent hours trying to realize its implications. If you’re not familiar with Fermi’s Paradox, I can help with you that. So according to the famous Drake Equation that I’m sure some of you may have come across, we can assess how many active, communicative extraterrestrial civilizations may exist in the Milky Way. Although, it works on several assumptions (we can assume that the Earth is special and the only planet capable of hosting life and the equation would tell us that there aren’t any other intelligent civilizations other than on Earth), but by making assumptions based on everything we know about how life formed, the abundance of organic material in the universe and perhaps most importantly just the sheer number of stars and planets that exist, we can estimate that there should be tens of thousands of intelligent civilizations in the Milky Way itself. Now that leads us to Fermi’s Paradox which led to Enrico Fermi famously asking “Where is everybody?”. According to Fermi’s Paradox, if intelligent life is as abundant as we think it is, we should have encountered aliens one way or another but for some reason, we haven’t. Considering that the Earth is approximately 4.5 billion years old (Creationists, seriously fuck off) with life arising somewhere between 3.5 to 4 billion years ago and modern humans (Homo Sapiens) arising on the scene only about a 100000 to 50000 years ago. We are living proof of how fast an intelligent race can advance. In a few million years, we went from living in the wilderness resembling chimp more than human to sending probes and satellites into other planets in our Solar System. There are billions of Solar Systems much older than our own with planets much older than Earth with life probably arising much earlier than life on Earth too. What if an intelligent civilization got a head start of even a million years more than us? It is only logical to assume that they would have advanced even more than us, possibly to the point of interstellar travel. But that’s not what we see though is it? We have seen no evidence of any other intelligent species apart from us so far. No communication signals, no signs of interstellar travel or literally any activity that seems to suggest they exist. At least one civilization somewhere out there would have tried to communicate right? But why haven’t we heard anything yet?

This leads to my solution to Fermi’s paradox. I must add that, I’m not the first person to think of this. These ideas aren’t unique to me. This is just my personal opinion from everything I’ve read and all the research I’ve done, all supported by the most compelling pieces of evidence that I could find. I encourage you to re-read the article as many times as it takes you to understand it (there may be a few concepts that may be a bit complicated for some of you) while at the same time, I encourage you to do your own research.

The Statistical Drake Equation(SDE) (which is different from the Classical Drake Equation (CDE)) uses the Central Limit Theorem as it foundation and we can expect the results to be more accurate than the CDE. By assuming that the Earth isn’t rare and that life in universe is abundant the SDE tells us that there maybe around 5,000 intelligent civilizations in the Milky Way with a pretty high standard deviation of around 11000 which would imply that they could be as many as 15,000 intelligent civilizations or as few as zero civilizations apart from the human race. Considering that the Milky Way is around 100,000 light years across (it would take light, the fastest thing in existence a 100,000 years to travel the length of the Milky Way!).

Dividing the total length of the Milky Way by the number of civilizations, we get an average of distance of 20,000 light years. Of course, standard deviation would mean they are a few civilizations that are closer and few that would be further than 20,0000 light years. But the average of 20,000 light years is a huge distance that many people will struggle to even comprehend. Electro-magnetic communication we are using right now would take approximately 20,000 years to reach those civilizations! Radio waves were only discovered at the end of the 19th century with radio communication only becoming prevalent in the early 20th century and humans started sending signals into space with serious intentions of communicating with alien civilizations only in 1974 with the Arecibo message. The Arecibo message is only 41 light years from Earth, quite far away from the average of 20,000 light years when can start to expect alien civilizations. Add to this the fact that it would take another 20,000 years for an alien civilization to return a signal, we can start to imagine how communication using electro-magnetic waves can be well, a little tricky.

But it still begs a question though. Why haven’t WE received a signal yet? Apart from the “WOW Signal” which is inconclusive in itself, we haven’t really heard anything from anywhere. Is the universe really such a desolate place? Are we alone? Well, a possible solution to this problem would be that maybe intelligent civilizations move on very quickly from using electro-magnetic communication to other, more advanced and faster forms of communications such as gravity waves (perhaps?). We will only truly get a good idea of this by seeing how long it takes humans to move on to a more advanced form of communication but considering the fact that technology is evolving an exponential rate, let’s just make an assumption that we will continue to use the same form of communication for 300 years which is honestly more than what current growth rates predict but for the sake of this argument, let’s just say 300 years. So the window for a civilization using electro-magnetic communication is only 300 years. Humans have only seriously started to listen to space in the last century. So, of the 13.7 billion year history of the universe, humans have been sending and listening to signals only for about a 100 years which constitutes about 2.06896552^-8 of the age of universe, slightly pathetic if you ask me. So, what is the likelihood that of the 300 year window of electro-magnetic communication that civilizations use, it happens to fall in the 100 years that humans have been listening to space? The answer is that it is highly highly highly unlikely. The odds of you winning the national lottery is higher. Aliens civilizations might have sent out electro-magnetic signals anytime during about 10 billion years of the existence of the universe (considering it took around 3 billion years for life on earth to evolve from single celled organisms to humans and assuming evolution works similarly everywhere in the universe) only for about 300 to an extreme assumption of a 1000 years (highly unlikely considering current growth rates). A hypothetical situation to make this more clear; perhaps aliens sent signals towards earth anytime before the 19th century, we would have missed them. On the other hand, if they send signals anytime after the 300 year window of electro-magnetic communication, we will miss them. Again, it’s easy for you to imagine just how unlikely it is that we will detect these signals.

Now on to the next question, why haven’t we been visited by aliens or seen any signs of interstellar travel? This question is far easier to answer. Maybe they just don’t know we’re here? The earth is in quite a lonely place in the galaxy, somewhere in one of the outer arms of the Milky Way, quite some distance from the center where the concentration of stars and planets is much higher. Once, they do detect us however, we can expect to be WIPED OUT. This is a pretty strong claim but it is only logical. Why would an intelligent civilization spend a tremendous amount of energy that is required to travel through huge distances in space only to come and say hello and make peace. That makes no sense. Like Stephen Hawking said, the threat from alien civilizations is very real. We are treading thin ice by sending signals out into space. If our signals are detected by a conquering alien civilization, we can truly expect to be wiped out. The fact that this hasn’t happened yet proves that we haven’t been detected by a civilization capable of interstellar travel. Just goes to show how lucky we are. Be grateful that we haven’t been detected yet. If humans haven’t advanced to the point where we can defend ourselves against invading civilizations by the time we’re discovered, we can kiss the Earth good-bye.

Other solutions do exist for Fermi’s Paradox like the simulation hypothesis which suggests that the Universe is simulated with us as the only intelligent species, The Great Filter theory which suggests that there exists a sort of “filter” where upon reaching a certain point of technological advancement, civilizations end up self-destructing through war or catastrophe. These are slightly more “exotic” solutions which I’m not convinced by. The simulation hypothesis is compelling but makes far too many assumptions for my liking. The Great Filter theory makes sense but where it falls short is, it assumes that ALL civilizations end up destroying themselves. While it may be the case that a few or the majority of civilizations end up self-destructing, it is not likely that ALL of them will given the sheer number of planets in existence. A few or most of them will survive depending on the likelihood of a civilization to self-destruct.

Sources for your convenience:

http://www.astrobio.net/news-exclusive/at-last-how-many-alien-civilizations-are-there/

https://en.wikipedia.org/wiki/Arecibo_message

https://en.wikipedia.org/wiki/Age_of_the_universe

https://en.wikipedia.org/wiki/Fermi_paradox

