Chen Chen knows that the so-called civilization filter theory is actually an explanation of the "Fermi Paradox".

In 1950, when the North American physicist Fermi was discussing the issue of flying saucers and aliens, he once asked a question: "Where are those aliens?" ”

This question, put on ordinary people, is just a curiosity about the unknown and imagination of the vast universe, but in the mind of this Nobel laureate, there is a kind of thoughtful and terrifying reality-

Looking at the data of the entire universe, the observable universe of human beings is 12.7 billion light years, the age of the universe is 136.2 (error 120 million) billion years, and the entire universe has more than 100 billion outer river systems, and the Milky Way is only one of the many living beings, just like a grain of sand on a beach, or even worse.

On such a macroscopic scale and over time, why haven't we humans discovered other extraterrestrial life?

The question may be a bit general, so the scientists decided to refine the problem more elaborately - first, considering the non-breakthrough of the speed of light, and the closest river system to the Milky Way is also 3 million light years, so the existence of life in the outer river system is not considered.

Second, there is a tendency to think that life forms in the universe are not limited to carbon-based life, so other types of life may exist, but humans are not aware of it, especially the most well-known example of "silicon-based life".

However, according to the fact that life is at least a complex individual that selectively exchanges matter with the surrounding environment, and there is no environment outside the basic physics of the entire universe, that is to say, the basic laws of the entire universe are unified, which are all composed of the four fundamental forces, as well as atoms, protons, electrons, and other substances, and the periodic table is also arranged in the same way, then the only element that can give birth to life is the most stable carbon element.

The carbon element has the structure of the outermost 4 electrons, which is equivalent to having four hands, each of which can grasp a other atom, and can even hold hands with other carbon atoms to form 4 stable covalent bonds, which is already the limit of the number of chemical bonds formed by the elements.

It is true that in addition to carbon, silicon is the easiest to give birth to life in the entire universe, but the number of electrons outside the nucleus of silicon atoms is one layer more than that of carbon atoms, and the electromagnetic force is weaker, and it is not as competitive as carbon-based life in terms of the birth of life.

Carbon is like a courtesan that can attract a variety of different atoms to bind to it, and the variety of compounds formed with other elements is almost infinite.

Therefore, it can be said that if there is indeed other life in the universe except humans, then 90 percent of them are carbon-based, 9 percent are silicon-based, and the remaining 1 percent are other forms of life.

So, after compressing this question of life in the universe to the scale of the Milky Way and carbon-based, we will get such a data - the Milky Way is about 12.5 billion years old, 2,000 light-years thick, 160,000 light-years in diameter, and there are about 100 billion sun-like stars in it, and countless planets.

If the emergence of human beings is a miracle in the universe, then no matter how small the data of this miracle is, it will be surprisingly large after being placed in a star of the scale of the Milky Way.

According to the current knowledge of physics, chemistry, biology, cosmology and sociology, scientists believe that with the development of human science and technology, if there is an extraterrestrial civilization only 10,000 years earlier than the development of the earth, then its traces should have been all over the galaxy a long time ago, and the current galaxy should have been full of interstellar civilizations that colonized everywhere.

But the fact is that except for some rumors, human beings cannot find any strong evidence of the existence of aliens on the earth, and even radio telescopes cannot find the slightest trace of alien spacecraft or alien projects......

So, this goes back to Fermi's previous question, where are those aliens?

This question has become the classic "Fermi Paradox", which has been talked about by the scientific community to this day.

But at this moment, watching the video playback, Chen Chen showed an angry look of being tricked.

Xiao X looked back at Chen Chen, then looked at the video that was turned off, and couldn't help asking, "Your Excellency Godfather, is there anything wrong with what the other party said?" ”

"No, I couldn't agree more."

Chen Chen nodded, and then showed a strange look, "But what he said is something I already know, strictly speaking, his entire video only reminded me that human beings will encounter crises one by one, and other than that, in my opinion, they are all farts!" ”

Little X suddenly scratched his head, revealing a puzzled look.

"If you just listen to what he said, it's really bluffing, it's a civilization filter, and it's a U disk butterfly effect, but in fact, I know everything he said, and he didn't say a word about what I really wanted to know."

Chen Chen spread his hands, "What is the Great Filter Theory of Civilization?" In fact, it is just one of the explanations of Fermi's paradox, a man named Robin Hansen proposed this concept, and he divided the evolution of life to civilization into 9 stages, starting with a suitable planetary system, to the birth of self-replicating molecules, to single-celled life, sexual reproduction, multicellular life, animals, and then to the stage we are currently in, and finally to the interstellar colonization ......"

In other words, he believes that human civilization is currently in the eighth stage of the Great Filter, and the final stage of interstellar colonization is one thing that is missing - controlled nuclear fusion."

"Controlled nuclear fusion, we've achieved it?"

Little X hurriedly shouted.

"Yes."

Chen Chen nodded, "Someone once calculated that even if the chemical energy of the whole earth is used, it will not be able to support human beings to fly from the solar system to the nearest centaur galaxy within a few decades, which shows that the energy provided by chemical fuel is very poor, and its existence is at most a transitional product of human beings, and controlled nuclear fusion should be the initial energy system for human beings to enter space." ”

Xiao X heard that he checked it on the Internet, and then smiled, "If you only look at it from the point of view of evolutionary theory, this theory is valid, it took 4.5 billion years for the earth to give birth to human beings, and it took more than 200,000 years for human beings to give birth to science, in such a long history, as long as there is a devastating disaster, human civilization may be interrupted." ”

"Therefore, if there is no big filter, then life will definitely spring up everywhere, and there will definitely be a large number of civilizations ahead of mankind, then there will be aliens who have found the earth a long time ago, and not only that, but even now I can do it."

Chen Chen nodded, he knew that the reason why Xiao X said this was because with Xiao X's current ability, he could already make his own von Neumann probe.

The von Neumann probe, a self-replicating probe designed to replicate itself using raw materials found in any star system, and explore the universe, is named after mathematician Johann von Neumann.

All the functions of this kind of detector are based on the existing technology of mankind, but because of its self-replicating properties, according to scientists' calculations, even if only one such a detector is built, it only takes a million years for this detector to cover the entire galaxy.

So we can reverse the extrapolation to prove that since we have not found any other civilization von Neumann probe, can it be proved that there is no civilization in the Milky Way, or that there is no civilization more than a million years beyond human beings for the time being?

"So, there must be something like a big filter that hinders the bustling scene of prosperity between civilizations."

Little X finally deduced.

"That's exactly what you're saying."

Chen Chen replied, "That's why I said that this Zhao Shanhe said that it was all fart, the big filter in his mouth was obviously something else, but it didn't explain what it was, what it was if it wasn't a fart?" ”

"Not only that, but the Gaia he talked about, and the so-called disaster of the earth against human civilization, is actually a very common immune response."

Chen Chen continued, "The metaphysical point is that the earth treats human beings as alien components, and the proliferation and behavior of human beings infringe on the health of the earth, and the earth does not like to accommodate so many human beings, so it releases viruses, kills human beings, and maintains the balance of the biosphere, Marburg virus, Sudan Ebola virus, and Zaire ebola virus, all of which are the strongest forces shown by nature." ”

"To put it bluntly, it is actually human development that destroys the ecological balance, resulting in changes in the earth's environment, and these immune responses, including viruses and natural disasters, are actually just chain reactions after destroying the ecological balance."

"Ah, what a pit."

With Chen Chen's guidance, Xiao X slowly woke up.

"Not only that, but he mentioned that he was going to the movie "Strange Evil", and the impact that the USB flash drive would have on reality, these are all things that I already know, and even the concepts of 'memes' and 'antimemes', he didn't explain to me at all, but just said the name."

Chen Chen sneered, "In short, he seems to have told me a lot, but in fact, when he thinks about it, he doesn't say anything at all, and the whole article is just the warning of the so-called 'Great Filter of Civilization'." ”

Even this warning can be understood by the law of large numbers - in the large number of repetitions of random events, there is often an almost inevitable law, and this law is the law of large numbers. In layman's terms, it means that under constant conditions, the frequency of random events is similar to its probability, and there is a certain inevitability in the accident...... With the development of human civilization, it will inevitably encounter all kinds of accidents and crises, which is a fact that can be thought of with your feet. ”

Xiao X suddenly thought for a moment when he heard this, "I understand what you mean, the more advanced science and technology are, the more human beings will drift away on the road to death, the emergence of nuclear weapons is like this, it is also the first test of destruction experienced by mankind, and the shadow of nuclear war has been hanging over mankind since the late last century, even today is not over, and with the more and more advanced science and technology of mankind, nuclear weapons are just a beginning?" ”

"Yes, nuclear weapons are just the beginning, and with them are genetic weapons, biological weapons, antimatter weapons, and even memetic weapons that we are beginning to come across...... These weapons make it possible for human civilization to be destroyed by self-made weapons at any time, just like the USB flash drive planes we enter, with accident and inevitability. ”

"Is this the truth that all the human planes in the USB flash drive have been destroyed?"

Little X suddenly realized.

"That's just my guess, and I'm certainly not entirely right."

Chen Chen shook his head, "But it's still a lot stronger than this guy's explanation of half a bucket of water." ”

"Maybe the 'Great Filter of Civilization' in his mouth is not such an abstract concept, but a higher-level weapon like memetic technology or even the law of cause and effect?"

Little X suddenly reminded.

"It's possible that what you're talking about."

Chen Chen pondered for a while, silently wrote down Xiao X's reminder, and then said again, "It depends on what he wanted to do with this video, and now there are two possibilities, the first is that this video is his last words before going to "Black Hole Surface", in order to warn the second owner of the USB flash drive, but he didn't expect that he would eventually fail, and after merging with antimemes, he changed his mind and ran to harm me in order to regain his body. ”

"The second possibility is that he went to the Black Hole Surface plane itself to become one with the antimeme, and this video is another trap, like the four horror movies he put in the USB flash drive, but before it could be triggered, he was eliminated by me."

Speaking of this, Chen Chen took a deep breath and said, "I personally prefer the second option, because the first one may not explain why he wants to put four horror movies. ”

"But what is the specific situation, it is still very simple to verify, X, now that we know his name, you try to search for information about Zhao Shanhe from the entire World Wide Web level, if he is really that antimeme, after being killed by me at this time, there should be clues about him on the Internet."

"Understood."

Xiao X suddenly closed his eyes, and once again connected to the network and swept a wide range.

This sweep is several hours.

When four hours later, Xiao X opened her eyes again, but at this time, a trace of surprise flashed in her eyes, "Your Excellency Godfather, I found Zhao Shanhe's information!" ”

"Take it and see!"

Chen Chen hurriedly said.

Suddenly, a web page appeared in the void in front of Chen Chen, only to see that the year of the web page was 1988, and on the web page was a photo of an archive.

The webpage of that era can be said to be extremely simple, even the photos on it are black and white, and you can only see the words Zhao Shanhe, a graduate of the 88 class, and Wang Xi, a graduate tutor, on it.

And on the right side of this file, there is a photo, which is exactly what the man in the video just now looks like, but he looks much younger.

Seeing this, a touch of shock suddenly appeared in Chen Chen's eyes.

Zhao Shanhe, like himself, is a student of Jiaotong University!