We understand what the Fermi paradox is and how scientists explain that there are at least 300 million habitable planets in our galaxy, but we have not yet found evidence of intelligent life outside the Earth.
Over time, any civilization is able to achieve the technology needed for interstellar flight. At the same time, humanity has never encountered alien creatures.
These three inexplicable facts are united by the Fermi paradox. We talk about it and try to understand why we are still not familiar with hypothetical neighbors in the galaxy.
In the summer of 1950, four scientists from the Los Alamos National Laboratory, created as part of the Manhattan Project to develop atomic weapons in the United States, went to lunch. They discussed UFOs and laughed at those who believed they were real. The conversation moved on to other topics.
However, when they were already sitting at the table, Enrico Fermi, one of the creators of the nuclear reactor and Nobel Prize winner in physics, suddenly blurted out : “So where is everyone ?!” The researcher had in mind the inhabitants of other planets in the universe.
Over the next decades, various scientists developed Fermi’s thought. There is a chain of reasons why it seems that the collision of earthlings with aliens is inevitable:
1. There are billions of stars in the Milky Way, similar to the Sun.
2. With a high degree of probability, planets with conditions similar to those on Earth circulate around many of them.
3. Many of these stars and, accordingly, the planets revolving around them, are many times older than the Sun. If the Earth is not unique, then they should have evolved life even earlier.
4. Some of these civilizations most likely advanced the technology of interstellar travel.
5. Even with the relatively slow rate of development of interstellar travel, the entire Milky Way can be explored in a few million years.
6. Since many other “Suns” and the planets around them are billions of years older than the solar system, the Earth should have already been visited by aliens, or at least their research vehicles.
However, we have not yet found any (officially known) contacts with extraterrestrial civilizations or traces of their activities. This is the Fermi paradox.
Since the 1950s, scientists have been developing various hypotheses that try to make sense of the Fermi paradox. Here are the most interesting explanations.
There is no life outside the Earth
On other planets , a civilization similar to ours could not develop . The Earth is unique, since many factors coincided on it at once: from the right climate to evolution.
There is no intelligent life outside the Earth
Even if there is life on other planets, it does not have human-like intelligence. The big brain is not the crown of evolution, it is rather illogical, as it consumes a lot of energy.
Humans, primates, whales, dolphins, octopuses and squid are in the minority compared to millions of other non-intelligent species.
Moreover, only humans were able to turn to space. As researcher Charles Lineweaver notes , “The dolphins had about 20 million years to build a telescope, but they didn’t get there.”
There have been five mass extinctions on Earth, when a huge number of species disappeared in a short time on a planetary scale.
Other habitable planets in the Milky Way faced similar problems. There are many reasons: from asteroids to volcanic eruptions. Because of all this, a similar earthly civilization did not develop in the galaxy.
Intelligent life did not come to technology
Humans have the best technology in the universe due to a number of evolutionary factors and the availability of resources on Earth. Intelligent life on other planets could not build telescopes or spaceships.
Any intelligent life comes to self-destruction
Shortly after the advent of civilization to radio and space technology, it self-destructs . The rapid development of weapons of mass destruction can lead to the death of all living things.
The clearest example on Earth is nuclear technology. Due to similar scenarios, intelligent life on other planets has not reached the level of development of ours.
Alien life may be overdeveloped
People simply cannot yet fix the signals emanating from other civilizations. Just 500 years ago, even a simple radio message would have looked like magic and no one, even the most advanced scientists, would have been able to receive it.
What if aliens bombard us daily with information about their existence, but our technology is simply not advanced enough to recognize it?
Aliens are isolated from the outside world
Developed civilizations from other planets, through a technology similar to the digitalization of the brain, ” passed ” into their analogue of the virtual world and do not plan to get out of it.
Earth is intentionally avoided
Alien civilizations have long known that the Earth is inhabited. However, they prefer not to interfere, but simply watch people in the expectation that they will reach at least the minimum level of development necessary for contact. This idea is called the zoo hypothesis.
Konstantin Tsiolkovsky wrote about it in 1933: “On what is the denial of intelligent planetary beings of the universe based? <...> We are told: if they were, they would visit the Earth. My answer: maybe they will visit, but the time has not yet come for that. <...> The time must come when the average degree of development of mankind will be sufficient for us to be visited by heavenly inhabitants. <...> We will not go to visit wolves, poisonous snakes or gorillas. We only kill them. The perfect animals from heaven don’t want to do the same to us.”