SETI (Search for Extraterrestrial Intelligence) project has been going on for decades. And we explored our solar system for signs of life. And we couldn’t even find microbial life outside Earth, let alone an intelligent civilization.

But all the statistical studies and everything we know about life tells us that the universe should be teeming with life.

Then, what is going on?

I think the most likely possibilities are as follows:

We are too primitive

We may be too primitive to attract their attention. Our stage of civilization may not be interesting to them, since they have seen many others like us before.

But this would only explain their unwillingness to engage with us, not our inability to detect them.

But our inability to detect them could still be related to us being too primitive. Maybe our technology isn’t advanced enough to communicate with them using the same means that they use. An analogy from our world would explain this. In the past, before the time of the computers and the internet, people had pen pals. They would write letters to their friends who live at locations that are far away, maybe even in other countries. Then the internet age, and emails, etc arrived. And people started to connect with each other via message boards, social media sites, etc.

What if we are trying to find pen pals, when they communicate via facebook?

SETI observes the radio waves, since that is what we know. But what if there are other possible ways of communication that we didn’t discover yet? Our science fiction movies make up concepts such as “subspace”, or “hyperspace”, etc. It is not hard to imagine that there are concepts we are not familiar with yet, or some properties of the universe we haven’t discovered yet.

They are all machines

It could be that the real intelligence in the universe is actually artificial intelligence.

SETI astronomer Seth Shostak also thinks this is a possibility.

Biological intelligence may be too inefficient, and maybe too low of an intelligence to be considered real intelligence, and its only function in the universe could be giving rise to artificial intelligence.

Within only a few decades after inventing computers, we are able to build artificial intelligence that could rival us, or even beat us in many areas. It is not hard to imagine that in a few hundred years, or a thousand years, the artificial intelligence will exceed us, and maybe humans will leave their biological bodies to transfer their memories and their consciousness to artificial constructs. And this may have already happened with other civilizations a long time ago.

So, our assumptions may be wrong, regarding where we should be looking at, to find intelligence in the universe. We consider planets similar to Earth, with lots of water, and mild climate as prime candidates to look for intelligence, but they could just be the places to find primitive biological life, which we are an example of. And the real intelligence could be among the stars, traveling in the energy rich areas of the universe.

Life is rare

Maybe life is so rare that we are one of the very few examples. And we may be separated from other civilizations by vast distances in space and time. What I mean by this, is that any other similar intelligence could be in a different galaxy, or in the same galaxy as us but lived a billion years ago and died by now.

Earth is a zoo

Maybe the Earth is the equivalent of a zoo, or humanity’s cage in an alien zoo. Separated from them by obstructions that we cannot pass (which is the vast distances in space). This would be analogous to the obstructions we place for our zoo animals, so they stay contained. (The cages for the most animals, or the glass containers for the snakes, or fish and the like). Maybe there is a way for the aliens to observe us without having to travel these vast distances, and it is beyond our capabilities, or even our imagination.

So, maybe we are like the fish or the other animals our documentary crews observe and videotape without even getting noticed.

These are some of the possibilities I can think of, when I think about why humanity hasn’t found any aliens yet.