Li Hao just began to see this very regular signal. He didn't care at all, there were too many complicated signals in the universe.

But he glanced at the signal captured by the space shuttle for the first time, and he always felt as if he had seen it somewhere.

With his memory, as long as he sees it, he won't be unable to remember. I can't remember it at first, I can only think that the signal I saw before is structurally similar to it. The content is still slightly different.

Li Hao's brain was running at high speed, carefully thinking about where he was, and seeing a signal similar to this.

Just thinking about it a little, Li Hao remembered that it was when he was translating the materials of alien civilizations a few days ago. See an alien civilization book called "Popular Science of Low-Level Civilizations".

He was curious about the science and technology library civilization he had obtained, and how they graded it. The parts that interest him were translated.

Alien civilizations divide civilization levels into five levels: the era of ignorance, low-level civilization, intermediate civilization, high-level civilization, and overlord civilization.

It is based on the size of the civilization's control area, which is the control area, not the explored area.

Just like the current human civilization, they do not have perfect control over the regions of the earth. It's like deserts, polar regions, and the bottom of the sea are not controlled by civilization.

Li Hao remembered that the era of ignorance meant that he had not found the direction of his civilization and was still active within a light year near the birthplace where his civilization was born.

He didn't believe it, but how to compare the situation of human civilization, according to the classification of alien civilizations, he was in the most basic era of ignorance.

A low-level civilization is a civilization that has already possessed the rudimentary space navigation, controlling an area within ten light-years and exploring within a range of hundreds of light-years.

Intermediate civilizations are those that have mastered a million light-years of territory, which is not described in the book.

Advanced civilizations and overlord civilizations, the territory they control has involved the spatial dimension. Li Hao still can't understand the meaning of the space unit introduced in this book.

This book focuses on the situation of the lower civilizations, and there is a chapter on the means of communication of the lower civilizations.

The book says that electromagnetic communication, telepathy, atomic resonance and other means commonly used by civilization in the obscurantist era are no longer convenient under the huge spatial amplitude.

A common method used by lower civilizations is to use the huge gravitational pull generated by neutron stars, and use gravitons as a medium to transmit information.

In the process of using gravitons to transmit information, it is inevitable that very regular gravitational waves will be generated.

Just like the electromagnetic waves generated by electromagnetic communication, they are different from the chaotic electromagnetic waves generated in nature, and the electromagnetic waves that have been modulated show extremely regular characteristics.

Although Li Hao couldn't understand the meaning of gravitational waves, he could confirm with certainty that this kind of extremely regular gravitational waves may have been modulated by civilization.

If a natural star produces such a regular gravitational wave and transmits it to the vicinity of the earth, this probability is too low, lower than the probability that the universe will be destroyed now.

It is only possible for civilization to show this characteristic if it continuously produces such gravitational waves.

Li Hao has read the book "Popular Science of Low-level Civilization".

He knew that the current human civilization would encounter such a low-level civilization. There are only two kinds of ends, enslaved or destroyed.

The hierarchy of civilization is extremely strict, in such a complex situation as the universe. It can't meet a certain scientific and technological standard, and it can't master such a large area.

Li Hao is really a little scared now, afraid that one day, this low-level civilization star destroyer will suddenly sail to the solar system. Destroy everything cleanly.

Zhou Yunsheng saw Li Hao's performance, she took out a handkerchief, wiped the cold sweat on Li Hao's face, and said gently: "Brother Hao, what's wrong with you." ”

An embarrassed smile appeared on Li Hao's pale face, and he said weakly, "I'm fine." ”

He kept encouraging himself in his heart: "Don't be afraid, don't be afraid. will always find a way to deal with it, and he has civilization technology in his hands that is far higher than that of low-level civilizations. As long as it doesn't happen now, there is always a way to deal with it. ”

Li Hao's expression gradually recovered, his voice was hoarse, and he ordered unquestionably: "Director Bi Ye, you immediately analyze this gravitational wave in detail. Concentrate all the strength of the physics laboratory and try to analyze all the data that we can analyze. ”

"Parrot" Li Hao shouted at the void in front of him.

Soon, the green-haired short-legged parrot floated in front of Li Hao.

It shook its little head and said, "Boss, please give the order." ”

"Issue the highest order for the Space Exploration Group space shuttle to depart again, with gravitational wave probes in the most reasonable layout. Go all out into space to collect gravitational waves similar to this one.

So that they don't have to think about the space shuttle and focus on collecting this data. Even if the shuttle gets out of control and cannot return to Earth again. They also want to collect this data comprehensively. ”

The parrot flapped its little wings and replied, "The order has been given, and Ma Yiming and Niu Zhengfeng are urgently executing the order." The shuttle is expected to fly into space again in an hour. ”

Li Hao must send the space shuttle into the sky again to see if it can collect gravitational waves similar to it near the earth.

If it is the means of communication of a low-level civilization, it is like the current earth that generates electromagnetic waves every day.

Because of the special needs of communication, they will also send gravitational waves all the time.

If this regular gravitational wave is received again, two cases of misunderstanding can be ruled out. There must be a low-level alien civilization near Earth.

One of the two things he needs to rule out is that the gravitational waves are naturally occurring by extreme coincidence.

Naturally occurring gravitational waves, which have reached the same morphology as those tuned by civilization. This is extremely unlikely, but it is not impossible.

The second is that because of some coincidence, the gravitational waves generated by low-level civilizations coincidentally came to the earth.

If there are no low-level alien civilizations around Earth, this possibility is almost the only possibility.

Because the stars in the universe are moving at high speeds, some move fast, some move slowly.

Their relative positions are constantly changing. Perhaps the gravitational wave signal he sent at a certain location happened to be passing by the Earth.

The transmission of gravitational waves takes time, and this low-level civilization is now located far from the space where the Earth is located.

You must know that according to the current movement of galaxies, scientists predict that the Milky Way will collide with the Andromeda Galaxy in three billion years.

In either case, this gravitational wave would not have been detected again around the Earth.

Zhou Yunsheng carefully checked Li Hao's physical condition with a smart ring, and she found that Li Hao was not sick.

And to see this strange behavior of him, and the unusual command. Knowing he has something on his mind.

Zhou Yunsheng helped Li Hao, and at the same time said to the three laboratory directors: "Brother Hao and I will go to the lounge to relieve ourselves, and you will work according to Brother Hao's instructions first." I'll be looking for you again if there's something. ”

Li Hao felt physically and mentally exhausted, so he went to rest with Zhou Yunsheng.

patted the head of the baby dog lying on his shoulder, and sighed in his heart: "How good it would be if I could live a carefree life like a dog." ”