ARE WE ALONE?

Hi everyone! Today I want to start asking you a question: how big is the universe? “Huge” many of you will answer. And  that’s true! Our universe is enormous, maybe even infinite.  And from our small planet, we can only see a tiny portion of it. So, if it is so big, then it should be reasonably full of life, right? I mean, statistically speaking is very improbable that ours is the only planet in the entire universe in which life flourished. There must be others.

But,  before we delve more into this, let’s take a step back. While our universe is indeed enormous, the majority of it is probably out of our reach. That’s because of its expansion: the distance between us and the rest of the universe grows exponentially  every second. So, even if we had super-fast spaceships, we wouldn’t be able to reach anything outside our Local Group.

So, let’s focus on our galaxy, the Milky Way. According to our evaluations,   there around 400 billion stars in it, and one twentieth of them are similar to our Sun. Of those, one fifth has probably got at least one planet in its habitable zone, that area of a solar system in which life can exist. If only 0.1% of those planets harbor life, then there should be around 1 million different alien species in our galaxy. And,  if we consider the fact that our galaxy is 4 billion years old, then the probabilities life has developed somewhere increase even more.

So, even if our scope is pretty limited, statistics say that there should be thousands of different alien civilizations out there. But if it’s true, then…where is everyone? Where are all the aliens? Why haven’t we   meet any of them yet? This is the so-called “Fermi Paradox”, something we still haven’t found a solution to. But over the course of time, we have come up with some theories.

One of them is the concept of “Filter”. Maybe there are some kind of events that act as a barrier, making it more difficult for life to develop properly. Maybe, every civilization at one point discovers new technology that ends up destroying them. Maybe,  climate change causes mass extinctions , wiping out life from every habitable planet. Or,  maybe,  for life to just pop out some kind of primordial soup is extremely rare. So, probably,  we are just doomed to end tragically, just like our fellow aliens who came before us.

Or maybe there’s no filter, and we haven’t discovered alien life forms yet simply because we still don’t have the technology to make it. After all, we have had the technology to at least communicate over large distances only for about a century. So perhaps we are still too primitive to meet the aliens.

Or…maybe there are no aliens, maybe we are really alone. Maybe our dear, beloved Earth is unique, the only planet in the universe capable to sustain life. Maybe we are the first civilization of the universe, and maybe we will be forever the only one.

 But in the end, the only thing we know for sure is that we will probably never have an answer to this question. We will probably continue talking about aliens forever, without ever meeting them. This is how life and time work. And maybe, looking up to the sky, and wondering if there’s someone else out there, is what truly unite all  life in the universe.

Well, that ‘s all. Have a nice day, and enjoy the stars!

Yuri