What is extraterrestrial life? Extraterrestrial life refers to life forms that do not originate on our planet and do not exist on Earth, so the term covers all possible life forms outside of Earth. These life forms could be viruses, they could be plant-like life forms, and some people go even further that they are looking for intelligent beings. They are very similar to humans in complexity, even surpassing humans, which is the classic alien image, but if there is extraterrestrial life, why has no one ever heard of so-called aliens until now?
Even the Fermi paradox is needed to solve this problem, and for this, you can find a way to solve this problem here.
The Fermi paradox is an idea conceived by physicist Enrico Fermi in 1950, Fermi hypothesized the existence of extraterrestrial life or extraterrestrial intelligence that should have enabled technologically advanced colonists to survive for millions of years.
During this time, it should be possible to colonize the entire galaxy, traveling through intergalactic and interstellar space, Fermi thought further
He assumed that this had already happened. However, the search for aliens has so far been unsuccessful.
This is paradoxical to the scientist, and as such, he questions his own observations and assumptions. These observations and assumptions lead to the Fermi Paradox. Because the universe is very old, and there are many stars, there should be life beyond Earth, unless the origin of life on our earth is an unusual process, which is also known as the rare earth hypothesis.
Assuming that Earth does not have a unique place in our solar system, and that there are other technological civilizations in our galaxy, although the width of the Milky Way is about 100,000 light-years, it will still take up to 10 million years to travel at subluminal speeds to complete such a distance, so we conclude that the age of the Milky Way is about 10 billion years, and if there is a civilization in the Galaxy that can colonize interstellar, the entire Galaxy will be completely colonized, and it will only take a few million years.
But the Milky Way is much older than it needs to be at least 20 years. So extraterrestrial life should exist somewhere near Earth, but to this day no evidence of extraterrestrial life has been found. So in short, the paradox is, if aliens do exist, why aren't they here? Why isn't it around the earth yet?
Drake's equation is closely related to the Fermi paradox, and so far most of the parameters of this equation are still unknown, so it doesn't do much to solve this paradox.
The Drake equation refers only to the Milky Way, our galaxy, which is a barred spiral galaxy with about two-thirds of the galaxies in the universe
It is constructed according to its type. From the universe observed today, there are about 100 billion galaxies similar to the Milky Way. The final value derived from Drake's equation, which must be multiplied by a relative factor for the entire universe, although this greatly increases the total number of possible civilizations, the calculation is still very imprecise because of insufficient knowledge of other galaxies.
In addition, the Drake equation refers not only to the theoretical number of civilizations, but also to the possibility of establishing a connection with them, the nearest galaxy is the Andromeda Nebula, but it is 2.5 million light-years away, so this galaxy is no longer within the consideration of actual contact. So all other galaxies don't think about it either, assuming we're really lonely, a paper says that multicellular life in space is very rare, even for terrestrial planets, because many impossible coincidences meet each other.
So life on Earth can develop, and the existence of other terrestrial planets is also impossible, and these coincidences include the existence of the Moon and the position of the Earth in the solar system, which ensures that the temperature of The Earth is suitable for life.
In this interpretation, the parameters of the so-called Drake equation are chosen in such a way that in the galaxy in which we find ourselves, only our civilization exists, so the Fermi paradox no longer becomes a paradox.
Because one of the basic assumptions is rejected, this hypothesis is convincing to many scientists, but some scientists believe it
Terrestrial planets do exist, especially as the fact that more and more exoplanets are being discovered supports this hypothesis.
Interstellar colonization is impossible, and the prerequisite for the Fermi paradox is a civilization capable of colonizing the stars, however, this is not possible in principle, because under this premise, there may be some technological civilizations, but they cannot affect each other because space is too far apart.
Here's an example of the distance from the sun to the star Proxima Centauri, and the nearest star will not arrive until years later, even if traveling at the speed of light.