Jiang Xiaolan said disappreciatively: "The astronomer's analysis may be more reasonable than yours, why don't you believe what others say?"

"Maybe they have a point, but I think it's ridiculous for some people to think that humans are orphans in the universe," Li said. ”

Jiang Xiaolan said: "Don't you believe in the results of data analysis the most? These views of other astronomers are also deduced and analyzed by data, so why do you think they are unreasonable?"

Li Xin said: "I always feel that their ideas are too harsh, and they always infer the existence of aliens according to the ideas of earthlings, which is a bit problematic." For example, they have been inferring that there must be sunlight, air and moisture on the alien planet according to the environment in which the earthlings live, and there must be a suitable temperature, preferably like the earth, the axis of rotation and the axis of rotation have a proper inclination, so that the four seasons can be formed on the planet, so that life can exist. However, such an environment is suitable for earthlings, and aliens may not need this environment to survive. For example, in some parts of the Pacific Ocean, where there is neither sunlight nor air, the pressure under the water is hundreds of times higher than the pressure at sea level, and the temperature is very high, and there are sulfides that are highly toxic to humans. It stands to reason that it should be a forbidden area for life, right? But in that place, many creatures that were unknown to humans were found, and they all lived there well. This proves that even on Earth, there is life that survives in extremely harsh environments. Note that the extremely harsh environment mentioned here is for humans, and for those creatures, that environment is what they think is comfortable, and if you take them to an environment that humans feel comfortable with, they may die out immediately, and the environment suitable for human beings is an extremely harsh environment for them. ”

Jiang Xiaolan said thoughtfully: "Are you saying that such deletion conditions are too harsh, so they think that the possibility of aliens is too small?"

Li Xin said: "Yes, I don't think their brains are big enough, the environment of the alien planet may make us unimaginable, and it is too narrow to use the environment of the earth to speculate on the living conditions of extraterrestrial life." For example, scientists nowadays have always believed that there must be water to have life, which is the case on Earth, but this may not be the case on alien planets, and alien life will definitely need water? Not necessarily, maybe what they need is alcohol? Is it sulfuric acid? Also, most of the popular speculations about the image of various aliens are similar to the image of human beings, and the specific image is still two hands, two feet and a head, but the hands and feet, the body, the head, The proportions of the eyes are different from those of earthlings, and I think this speculation is too funny. ”

Little Glasses asked, "Do aliens drink alcohol or sulfuric acid, not water?" Li Xin, your brain is big enough, so what can you tell me about the shape of the aliens?"

Li Xin said: "I can't say this well, anyway, even if you imagine it as something like cockroaches, centipedes, and caterpillars, I feel that the imagination is not big enough and not broad enough." You have to think that they are not only aliens, but they are aliens in another galaxy, on another planet. They may not have the shape of our brains, and they may not have the familiar eyes, nose, ears and mouth, which are very ugly, because they don't need these things at all. ”

The little cookie, who had been listening quietly to the side, said: "I think what Li Xin said makes sense, if there are aliens on the alien planet, they are much smarter than us is a high probability event." Because the existence of intelligent beings on the earth has only been tens of thousands of years, these tens of thousands of years can be said to be only an insignificant moment in the history of astronomy. Then, in a broader time frame, the time when intelligent life on alien planets began to evolve is not to say hundreds of millions of years earlier than ours, or even billions of years, as long as their evolution history is millions of years earlier than ours, and their degree of civilization is also unimaginable now. ”

The old girl said, "If the aliens are so much smarter than us, it is understandable that we can't find them, but why can't they find us?"

Li Xin said: "I think the main reason is that the universe is too vast, the distance between galaxies is hundreds of millions of light-years or even billions of light-years, and even the light with a propagation speed of 300,000 kilometers per second has to travel hundreds of millions of years to reach each other's position, not that they don't want to find it, but that there is really not enough time." It's like an ant in the Taklamakan Desert, if you want to meet another ant in the Sahara Desert, even if they find each other's position, although they try to run towards each other, but before they reach each other's position, their lives are over. If they don't even find each other's position, and can't be sure if each other exists, then it is impossible for the two to contact each other and meet each other. ”

The old girl exclaimed: "Your analogy is very vivid, and it is easy to explain the difficulty of finding aliens." Isn't it possible that we'll never see aliens?"

Li Xin said: "There is really such a possibility, maybe by the day the earth is destroyed, the earthlings will not be able to contact the aliens." ”

The old girl said: "It's a pity, nothing is faster than the speed of light, otherwise, the time of interstellar travel can be greatly shortened, and there is still hope to see aliens." ”

Li Xin said: "In fact, nothing can be faster than the speed of light, and I think it is a bit too absolute. ”

Jiang Xiaolan smiled: "You are so bold that you dare to question Einstein's inference." ”

Li Xin said: "I'm just a personal guess, I don't study physics, and I can't find any basis to say that he is wrong, I just think his statement is too arbitrary." Humans have only figured out what light is just over 100 years old, and it would be too early to say that nothing in the universe can be faster than the speed of light. Isn't there a theory of the expansion of the universe recently? It is said that the farther away from the Earth, the faster the planet is leaving the Earth. At a certain distance, the planets there leave the Earth so fast that even their rays can no longer reach the Earth, which means that the planets on Earth will never be seen that far away. It's a paradox to say that nothing in the universe can move faster than the speed of light, and then to say that the planets are so far away from the Earth that their rays can't reach the Earth. This is obviously like the paradoxical example of ancient China, and one of the two must be wrong, that is, the speed of light in the universe is not necessarily the fastest. ”

"Regardless of whether the speed of light is the fastest or not, let's just say that aliens are so much smarter than us, if they find us, how will they communicate with each other, will they help us?"

Li Xin said: "This problem is even more terrifying. ”

Little Glasses asked, "Why do you say horror?"

Li Xin said: "Think about it, how do we treat cattle and sheep?"

Little Glasses said, "You mean aliens will harm us earthlings?"

Li Xin said: "I don't know, but I think if we are smarter than the aliens, we will find them first, and the initiative is in our hands." But if the aliens were so much smarter than we did, and they found us first, we wouldn't be able to do anything. ”

"Didn't you say that they are much more civilized than us?" and "how can they be so cruel? ”

Li Xin said: "The level of civilization and the level of morality have always been two concepts. Even on Earth, in human society, the infiltration of one more advanced civilization into another civilization has been in the form of invasion, not to mention the infiltration of civilization between different species. Everyone is familiar with the term biological invasion, right? This is still the case among the creatures on the earth, and the invasion of the civilization of alien creatures on our earth is even more unimaginable. It is possible that they have a high level of civilization and morality, and that would be a blessing for the people of the earth, but you have to think about it, if this is not the case, if their moral level does not match the level of civilization, it will be a disaster for the people of the earth. And even if they do, we say that their moral level is not high, but only from the point of view of us earthlings, if we understand it from the perspective of their aliens, they may take it for granted, and it has nothing to do with the level of morality. ”

"So, it's not a good thing to meet aliens!"

Li Xin said: "Yes, so now some rational scientists are persuading human beings to pay attention to hiding human beings themselves when looking for extraterrestrial civilizations. It's like when we go into a dangerous forest, the first thing we need to do is not to be discovered by the beasts first, otherwise we will be in danger. ”

When the little biscuit heard this, he said, "The more I listen, the more terrifying it becomes, and the hairs stand on end!"

Li Xin wanted to scare a few girls, so he said: "Yes, when you look up at the starry sky, maybe the aliens are also staring at you, he is thinking: This little thing is white and tender, is it better to steam or braise it at dinner?"

The little biscuit in the dark was so frightened that he grabbed Jiang Xiaolan's hand tightly, looked around the dark surroundings and said, "Li Xin, you are so annoying, telling these ghost stories to scare people!" Lan Lan, let's go back." ”

Jiang Xiaolan complained to Li Xin and said: "Look at you, everyone looks at the stars well, but you say so many strange things, which makes everyone more disappointed!"