Are we really alone in the universe, or is there anything out there?
We all have asked ourselves this question at least once in our lifetime. It just takes a starry night and a clear sky to start thinking about our existence.
I mean, look at this image and dare to tell me we are alone in the universe.
We humans have been living in this tiny planet called Earth for an even tinier amount of time. Don’t you believe me?? Take a look at these pictures.
The first one is a timeline of human existence throughout Earth’s history. The first homo sapiens appeared 200,000 years ago, whic may seem a lot of time comparing it, for example, to the average human life expectancy (80 years approximately). But now, compare that to the first appearance of simple animals, 600 million years ago. And that to the first appearance of simple cells, 3.8 BILLION years ago. Crazy, huh?
The second one is a comparison between the Earth’s size and the size of other planets and stars. Knowing that we can only see a part of the universe (the observable universe) and that we haven’t discovered more than 1% of it (no, I don’t know the exact number) we can assume that there are planets out there quite bigger than our Earth is.
So all of these things would make us think that there have to be any other life forms than the Earth ones. Right?
Well, nobody knows for sure, but there are things that indicate there could actually not be any form of life outside our planet. One of them is the Fermi paradox.
The Fermi paradox (or Fermi’s paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial life civilizations and the lack of contact with, or evidence for, such civilizations. The basic points of the argument, made by physicists Enrico Fermi and Michael H. Hart, are:
- The Sun is a typical star, and there are billions of stars in the galaxy that are billions of years older.
- With high probability, some of these stars will have Earth-like planets, and if the earth is typical, some might develop intelligent life.
- Some of these civilizations might develop interstellar travel, a step the Earth is investigating now.
Even at the slow pace of currently envisioned interstellar travel, the Milky Way galaxy could be completely traversed in about a million years.
According to this line of thinking, the Earth should already have been visited by extraterrestrial aliens though Fermi saw no convincing evidence of this, nor any signs of alien intelligence anywhere in the observable universe, leading him to ask, “Where is everybody?
Well, to end the post I want you to let me know in the comments if you think there is some kind of life in other planets. I personally think there has to be something, but I want to know your opinions on this. Bye!