In the 1950s, at the beginning of the space journey, full of curiosity and awe about the universe beyond The Earth, scientists gathered together to discuss astronomical knowledge, and just when the atmosphere was intense, a physicist named Fermi asked the question: Where are they? The fiery hall was suddenly silent and fell into contemplation.
The Fermi Paradox is a scientific paradox about extraterrestrial civilizations that elucidate the possibility of extraterrestrial civilizations existing but lacks precise evidence. In Fermi's eyes, the probability of other extraterrestrial life in the universe is approaching 100%, taking the Milky Way as an example, there are hundreds of billions of stars like the sun in the entire Milky Way, and the number of planets is innumerable. In the solar system, there are three Earth-like planets, and the earth happens to have intelligent life, from the perspective of probability, there should be at least a thousand life planets in the milky way, and the universe is even more immeasurable.
So why hasn't humanity found any other intelligent life yet? Under the analysis of scientists, the main reasons are divided into the following points.
<h1 class= "pgc-h-arrow-right" >1. Alien civilizations are too far away from us</h1>
We have no concept of the size of the universe at all, and can only be described by a "big" word. In fact, how big the universe is, has long been beyond our understanding, to know that the diameter of the solar system we are in is about 1 light-year, and 44 years ago, the "Voyager 1" launched by humans has flown non-stop to now fly 22 billion kilometers, but even 1% of the solar system has not flown out, according to this speed, human beings need tens of thousands of years to fly out of the solar system.
The outer part of the solar system is the Milky Way, the diameter of the Milky Way is 2 billion light years, the outside of the Milky Way is the entire universe, with a diameter of 93 billion light years, and the number of stars in the universe is as many as the water droplets on the earth, even if the probability of the birth of a living planet is one in a billion, there are still countless alien civilizations. Suppose there are alien civilizations, but because we are too far away from them to meet each other, and interstellar travel is a dangerous and long thing, even if our spacecraft reaches the other planet, the people on the spacecraft will have long since aged and died.
<h1 class="pgc-h-arrow-right" >2</h1>
Because we have been influenced by science fiction films and television works since childhood, many people have a stereotype in their minds that the degree of civilization of extraterrestrial life must be higher than that of humans. In fact, the degree of technology of mankind today has surpassed the vast majority of alien civilizations, and many alien civilizations may still be in the primitive stage, living a life of drinking blood.
Because of human exploration of space, they have a deep respect for the vastness and unknown of the universe, so that they think that there are people outside of people, and there is a sky outside the sky. From the perspective of human evolutionary history, we only took millions of years to evolve into today's appearance, and then only took two or three hundred years to change from feudal society to modern society, compared to the dinosaurs did not produce civilization for hundreds of millions of years, why didn't human beings achieve fruitful results?
In addition, the emergence of life is a mean thing, and the emergence of intelligent creatures is even rarer, coupled with the fact that there are too many uncertainties in the evolution of organisms, perhaps for some reason has been stuck in the primitive stage or feudal stage.
<h1 class="pgc-h-arrow-right" >3. Extraterrestrial civilizations are all around us</h1>
Since the birth of mankind, it has experienced 5 million years of wind and rain, which is very long for us, but it is fleeting relative to the entire universe, and many animals on the earth have evolved for hundreds of millions of years. Assuming that alien civilizations have existed for hundreds of millions of years, then their technological development is already incalculable, and at this point interstellar tourism is even easier, and their life forms are very different from what we look like in traditional thinking, even if they are around us, it is difficult to find them.
For this advanced civilization, we see them as ant beings, and our activities have no effect on them. At this point, some people will ask, so why don't they rob us of our resources? Similarly, do you value the resources of ants?
< h1 class= "pgc-h-arrow-right" >4. Extraterrestrial civilizations do not exist or have existed</h1>
The universe was born about 13.7 billion, and the emergence of human beings in such a long period of time has belonged to the aftermath, and there should be many other "predecessors" of extraterrestrial civilizations, but in fact, in the decades of exploration, we can't even capture their shadows, which seems to imply that human beings are the only intelligent creatures. If there really are extraterrestrial civilizations, then some advanced civilizations will always stand out among these alien civilizations, establish some cosmic systems, and the entire universe is like the biosphere on Earth, living in the same room and preying on each other.
Or rather, there have been extraterrestrial civilizations in the universe, but for some reason they have led to destruction, and the emergence of human beings is also a miracle within a miracle, becoming the pioneer of the new universe.
The above four about the existence of extraterrestrial civilizations are all scientists' speculations and publicly accepted statements, but the fact of whether extraterrestrial civilizations exist is unknown, perhaps only time can give us the answer, only human beings continue to explore and develop technology, I believe this answer will be solved in the near future.