Lead
In 1950, when Fermi heard some other physicists discuss the possibility of aliens, he asked, "We haven't found any signs of other civilizations, so where are the aliens?"
Since then, scientists have made a series of attempts to find extraterrestrial civilizations as a technical and scientific challenge.
It wasn't until 1992 that scientists found the first binary extraterrestrial planet, starting the search for extraterrestrial civilizations, and since then, scientists have continued to advance technology, with the technology that can detect terrestrial civilizations the size of Earth stars today, but so far, we have not found any signs of other life.
What's going on here?
The universe has existed for 13.8 billion years, but no other life has been discovered, where are the aliens?
1. There may be a large number of planets in the universe that are suitable for human habitation.
The Hubble telescope is one of the greatest inventions in human history, with the Hubble telescope, mankind stepped out of the earth for the first time and saw the vastness and beauty of the universe.
When the Hubble Telescope was first used to observe extragalaxies, a large number of galaxies were discovered and found to be very similar to ours.
In addition to galaxies, the Hubble telescope also captured images of the presence of planets in galaxies, which played a crucial role in proving the existence of extraterrestrial life, as numerous observations showed that almost every galaxy had Earth-like planets within the limits of the planets that meet the requirements for human habitation.
On these planets, there is often liquid water that can give birth to life, and there are atmospheres and clouds and other gases that can produce life, so it is inferred that life may exist on these planets.
The Hubble telescope is a very advanced instrument, and it is also the top device that human beings can observe the universe, but even the Hubble telescope can only observe the planets within the range of 90 billion light-years outside the earth, and the diameter of the Milky Way is about 100,000 light-years, which is only within the Milky Way, plus there are more than 200 billion galaxies in the galaxies outside the Milky Way, it is conceivable that there are not many planets observed by the Hubble telescope.
The Drake equation is a law discovered from the observation of the number of extraterrestrial civilizations, through this equation, scientists have found that only when there are planets around almost every star, the number of extraterrestrial civilizations calculated will be as many as there are hundreds of millions of Earths in the universe we have observed, and according to the observations of the Hubble Telescope, even in the universe we can observe, there are only tens of millions of planets the size of the Earth, which makes the number of extraterrestrial civilizations have a large gap.
In fact, this gap is mainly due to the fact that the observation range that scientists say is too small, if we add that the universe we only observe occupies a very small area of the outer periphery of the Milky Way, and there are thousands of stars in the center of the Milky Way, so there will be more planets in the galactic system where the solar system is located, and if the observation range of the universe increases, the number of alien civilizations will be close to the number estimated by the Drake equation.
According to this method, scientists believe that there may be 100,000 extraterrestrial civilizations in the Milky Way, which means that extraterrestrial life is very common, and if this is inferred, then the reason why mankind has not discovered other life so far will become more confusing, and the universe outside the galaxy will be more colorful.
Second, the big filter hypothesis.
Since the inference of the Drake equation is extrapolated from the phenomena seen in the observation of the universe, scientists believe that the difference between these three numbers may be due to the relative bias caused by the observation range, and thus speculate on the extraterrestrial civilization filter hypothesis that humans have not discovered extraterrestrial civilizations.
This hypothesis holds that in the path of civilization development, it will be filtered by various possibilities, and that countless crises in human development are due to this filtering, and this filtering may also be the reason why extraterrestrial civilizations do not have the opportunity to manifest themselves in front of us, and this filter is the big filter.
Compared with the number of 100,000 alien civilizations in the Drake equation and the number of hundreds of millions of Earth-sized planets in the universe, there is no doubt that alien civilizations are very common, but we have not seen or heard of any other life activities, which is very likely to be the effect of the big filter.
Perhaps, there are many planets where life has also come to the brink of destruction again and again, just like humans.
At present, there are two main filters faced by human civilization, one is the nuclear war in 99, the outbreak of nuclear war is the biggest crisis of human civilization, since 1950, people have a full understanding of the harm of nuclear war, many scientists have warned of the great destruction brought by nuclear war, but soon, the United States and the Soviet Union took the lead in nuclear testing in 1952.
The test accelerated the arms race between the United States and the Soviet Union, which was uncontrollable and soon reached the point of possession of millions of nuclear bombs.
Countless scientists have made a lot of explorations about the dangers of nuclear war, and the United States and the Soviet Union and the European Economic Cooperation Organization have also carried out many stages of cooperation, and by considering the various possibilities of nuclear war, they have developed an early warning system and defense system for nuclear war, but even so, the crisis of nuclear war still exists, and until 99, almost every country has a nuclear bomb and can start a nuclear war.
The crisis of nuclear war broke out in 99, and the negotiations between the United States and the Soviet Union heated up sharply, but there was a situation in the middle, the United States carried out a cruise on the missile stations of Czechoslovakia, a move that the Soviet Union saw as a threat to them, and then itself also established a number of nuclear bomb bases in Eastern Europe, and the two sides hit it off and soon fell into nuclear war.
It eventually led to the death of billions of people and the extinction of 99% of animals and plants, almost sending human civilization to hell.
3. Extraterrestrial life is likely to be a third-level civilization.
Another big filter may be just a few years ago, in 2020, brain-computer interface technology advanced by leaps and bounds, and in 2023, the first success of brain-computer integration was achieved, and from 2023 to the present, only less than 10 years have passed, brain-computer integration technology has made great progress, and it is developing in the direction of being able to install quantum computers as auxiliaries inside the human body, which will also make mankind enter an unprecedented era.
The upcoming era of brain-computer integration will bring a lot of convenience to human beings, but there are also many risks, such as privacy leakage, invasion of the mind, leading to human extinction and other risks, and these risks will almost lead to the destruction of human civilization, so brain-computer combination is mainly the filter of civilization, and in the opinion of scientists, the era of brain-computer combination will definitely come, so human civilization will definitely experience the filtering of brain-computer combination, and the filter before this may be the filter faced by extraterrestrial civilizations.
According to scientists' observations, it is very likely that the alien civilization is at least a third-level civilization, and the third-level civilization can easily dominate the energy of the entire galaxy, and can travel arbitrarily to any planet in the galaxy within a range of billions of light-years, and can easily observe and invade living planets.
Human beings are like the former natives who crawl in front of the alien civilization, at the mercy of them, and may even be used as experiments by the alien civilization like mice, and finally usher in the destruction of the human race, which may be the reason for the big filter.
There are many kinds of mechanisms of the big filter, and human exploration of extraterrestrial civilizations should also be more in-depth, and more possible filter mechanisms can be proposed through the big filter hypothesis in order to better understand the universe.
epilogue
Extraterrestrial civilizations, if they exist, are bound to have a profound impact on human civilization, and we need to be prepared to meet this challenge.
The significance of exploring the mechanism of the big filter is not only to find the location and mechanism of this filter, but also whether we can avoid possible crises and let the candle of human civilization continue to illuminate the world.
"Where are the aliens?"
Not only Fermi wants to know, but I also want to know that human beings should be more courageous to explore the unknown, and the search for extraterrestrial civilizations is not only a scientific issue, but also a promotion for human thinking and development.