Aliens, where are you? One of my dreams is the day I wake up in the morning, and when I check the news I see that we finally managed to find life outside Earth, on another planet or moon. I hope this will happen at least until 2080, which is probably when my life will be ending.
This subject is one of those I avoid thinking because it is so hard to explain – to myself – the reasons why the modern society still didn’t manage to find aliens. I always try to think that this is because we are still very far from developing technology devices, such as telescopes, spacecrafts and radio-receivers, that are capable of doing such task.
When I was a young boy I was very obsessed with them, my biggest fear of staying home alone was not because of burglars or ghosts, but aliens! I was sure the day I would be home alone an alien would invade the house and abduct me to execute horrible experiments with my body.
Also, I’m sure I saw aliens inside my house a number of times, they used to hide from me very well, but some of the times I could see their shadows, and once I saw the head of one of them. Yes, my imaginary friends were in form of aliens.
But thinking a bit more about it, it’s clear that we always tend to imagine an alien with a body similar to a human. Most probably they are not.
Sorry Darwin, evolution is great, but still very random. Very random. And what we have now on Earth is the result of billions and billions of random evolution and it has a huge number of variables on this equation, such as proximity of the Sun, amount of essential chemicals available, water and a source of energy.
When people think of living organisms, they typically think of organisms that can be seen in everyday life, such as plants and animals, but many living organisms go undetected by the human eye. Humans, with trillions of cells, have more in common with tiny single-celled bacteria than you might think.
The first cells appeared on Earth about 3.5 billion years ago, and one slightly change at the beginning of everything or a difference on the amount of chemicals would change everything. So, imagine that humans could never have existed and you and me now could be flowers, or another type of humans, less or more intelligent. Also, imagine that we could be humans without eyes, we could communicate with each other with our antennas like ants do. The number of variables are infinite.
It means finding aliens around us (less than 10 light-years of distance) that are similar to us in a way that we can have some kind of communication is insane.
For example, imagine that some aliens find Earth and stop their spaceship just outside our planet, like 10,000 miles from our surface. What if their eyes can’t see through our atmosphere? Our human eyes can see thought it because the density of the gases and the length of the light path allow it. What if their eyes are different, what if our atmosphere has the gray color for them? They will see Earth as a ball of a gray mix of nitrogen, oxygen, carbon dioxide and some other miscellaneous gases. Our society will be just a mix of random atoms moving around, which is actually what we are, a whole bunch of atoms. It’s sad, I know. And it’s similar to the way we describe a lot of stars and planets, like Jupiter, it’s considered a gas giant planet, but it does have a core with solid surface, and we have no idea what is in there.
There is something called Kardashev scale which is a method of measuring a civilization’s level of technological advancement, based on the amount of energy a civilization is able to utilize directed towards communication. The scale has three designated categories called Type I, II, and III. A Type I civilization is able to utilize and store energy available from its neighboring star which reaches their planet, Type II is able to harness the energy of the entire star (the most popular hypothetical concept being the Dyson sphere, a device which would encompass the entire star and transfer its energy to the planet), and Type III civilization are in control of energy on the scale of their entire host galaxy. Various extensions of the scale have been proposed since, from a wider range of power levels, such as as types 0, IV, V, Omega, where Omega is capable of manipulating the basic structure of space and time.
It means there might be civilizations out there that are capable of creating four-dimensional spaces, being able to travel to the past and future, which means we wouldn’t be able to find them, only if they were on our time point in the time arrow.
We are a tiny dot in this huge place we call universe. And we don’t know if this is the only universe. Which makes us even smaller, and tell us that finding aliens is just unlikely to happen.
Although, there is an equation called Drake equation, which is a probabilistic argument used to arrive at an estimate of the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy. The number of such civilizations, N, is assumed to be equal to the mathematical product of the average rate of star formation, R*, in our galaxy, the fraction of formed stars, fp, that have planets, the average number of planets per star that has planets, ne, that can potentially support life, the fraction of those planets, fl, that actually develop life, the fraction of planets bearing life on which intelligent, civilized life, fi, has developed, the fraction of these civilizations that have developed communications, fc, i.e., technologies that release detectable signs into space, and the length of time, L, over which such civilizations release detectable signals, for a combined expression of:
Current estimates gives the result of 36.4 million active, communicative extraterrestrial civilizations, just in our galaxy!
Even if the result would be 1, it would already be fantastic.