The edge of the solar system, outside the Oort Nebula.

A moon-sized starship is silently moored in the void.

Inside the bridge, the captain is communicating with the fleet commander a thousand light-years away through the intelligence field.

"Your Excellency Commander, the target system has discovered a self-evolving civilization 500921473, and it has now passed the first-level civilization test."

The captain said.

"I really didn't expect that in this desolate and empty place, there is still a first-level civilization that has evolved independently, and this area is really empty, with a star density of more than two hundred cubic light-years. Without the cultivation of advanced civilizations and sufficient resources, they would still be imprisoned in sub-light speed and three-dimensional space-time for two thousand years, and it would take at least another thousand years to master and use annihilation energy, and two thousand years later to communicate through multi-dimensional space-time, as for space navigation through hyperspace jumps, it may be five thousand years later, and it will take at least ten thousand years for them to have the minimum conditions to join the galaxy's carbon-based civilization family. ”

The commander said with some emotion.

The captain said, "Your Excellency, has this planet been included in the Milky Way Carbon-Based Life Alliance's civilization cultivation and expansion plan?" ”

"Blue 84210, you will immediately go to the galaxy to conduct a full-surface civilization test on Planet 3, and the tasks in front of your ship will be taken over by other ships. As for whether it will be included in the cultivation plan, we will wait for the test results to come out. ”

"Understood...... Hey, what's the situation? ”

In the computer, the sudden information caused the captain's intelligence field to become disordered.

The commander seemed to sense the captain's strangeness and asked, "Captain, is there any problem?" ”

The captain still seemed to be in a state of shock: "Your Excellency, there seems to be a problem with our ship's computer system, there is a digital replica that is conveying information to us, of course, it is also possible that the computer system is malfunctioning. ”

The commander was slightly stunned and said, "Synchronize the data of the blue 84210 ship's computer system." ”

In the next second, Pang Xuelin's voice appeared in the bridge of the flagship a thousand light years away.

"Excuse me, can I answer the test questions for the second-level civilization?"

Inside the flagship, the atmosphere suddenly became solemn.

Digital replicas, as the name suggests, are just memory replicas of living organisms, and self-consciousness cannot exist.

But now, this replica from a first-level civilization not only has an autonomous consciousness, but is even vaguely aware of the existence of the Galactic Overlord-level Alliance.

That's a bit scary.

The commander of the fleet turned his gaze to the scientific staff.

The scientific staff officer was conducting a comprehensive screening of the computer data inside the Blue 84210 ship, and after a while, the scientific staff officer said: "Your Excellency, the computer data is not abnormal. ”

The commander's intelligence field fluctuated violently.

No anomalies?

But they are aware of their presence.

Could it be that behind this first-level civilization, there is a super civilization that has never appeared?

"Agree to his request and give him the second-level civilization test questions."

At this time, the intelligent field fluctuations of the chief consul of the carbon-based life alliance, who received the relevant information through high-dimensional space-time synchronization, appeared in the flagship bridge.

"Yes!"

The commander frowned slightly, and immediately replied.

……

Within the digital void.

Pang Xuelin stood calmly in place.

He figured it was at least five minutes in the air.

Although they haven't received a reply from the other party, this digital space has not been closed, so it can only mean that the Carbon-Based Life Alliance has received the message from itself, at least they don't seem to have figured out how to deal with it internally.

"Will they agree to their demands?"

Pang Xuelin was thoughtful.

According to the previous civilization level test questions, the earth should be in the form of a first-level civilization, and if the other party agrees to tell himself the second-level civilization test questions, even if he can't answer them, he can find the direction of future scientific and technological development for human civilization.

Even further, through them to obtain more information about alien civilizations, even if there are certain differences in the laws of each plane, but it also has a high reference value for their future shuttle to various science fiction planes.

At this moment, within the digital void, an ethereal voice sounded again.

"Level 2 Civilization Test Question No. 1: Is the thinking activity of carbon-based organisms at the neuronal level, molecular level, or quantum level?"

Pang Xuelin's eyes lit up all of a sudden, and he said, "Quantum level? ”

This question is multiple-choice, but the answer to it has the potential to have a very significant impact on the future direction of human brain science research.

"Test No. 1 passed, Level 2 Civilization Test No. 2: Please briefly explain the mechanism of gravity generation."

“……”

Pang Xuelin's brows furrowed.

There used to be such a question: "If you catch up with a ray of light, what will it look like?" Will you see a still wave of light, frozen in time? ”

At the age of 16, Einstein discovered that nothing in the world seemed to be able to catch up with the speed of light. At the age of 26, he proved this discovery with rigorous mathematics. As a junior clerk at the Swiss Patent Office, he used Maxwell's field equation to derive the special theory of relativity.

To sum it up in one sentence, the speed of light is constant in any perpetual architecture.

This theorem may seem inconspicuous on the surface, but it is indeed one of the greatest achievements of human civilization in history!

Constant speed of light?? Time slows down?? The mass is not constant??" Mass-energy "interchange?? E＝mc??。

This is the whole process of derivation of the special theory of relativity, which unifies "space-time" and "mass-energy".

After unifying "space-time" and "mass-energy", Einstein further considered the relationship between "space-time" and "mass-energy", that is, acceleration and gravity, which are ignored by special relativity.

Hence the emergence of the general theory of relativity.

Let's start with a simple question.

"If a person is in free fall, he doesn't feel his weight?"

Einstein grasped the basic property of gravity through this simple problem: the laws of nature in the framework of acceleration are the same as the laws of the gravitational field. This is known as the principle of equivalence.

Using the principle of equivalence, Einstein rethought the question of the speed of light: the speed of light is affected by gravity, and the gravitational field distorts the path of light.

However, according to Fermat's principle of shortest time, light takes the shortest time path between two points, and Einstein once again came to a shocking conclusion: if we can observe light moving in a curve, it means that space itself is curved!

It is further concluded that the existence of mass energy causes the curvature of the surrounding space-time.

But until now, there has been no clear answer in the physics community, whether it is the existence of gravity that causes space-time to bend, or whether space-time bending produces gravity.

According to quantum mechanics, there should be a boson with a spin of 2 and a mass of zero, which is the legendary graviton.

However, when calculating gravitons, it was found that the theoretical results of gravitons were very different from the actual situation.

Therefore, until now, the physics community has not been able to give a clear answer to the mechanism of gravity.

Pang Xuelin blinked and said, "The bending of space-time produces gravity? ”

"The answer is wrong."

Pang Xuelin smiled, this reply was not expected.

However, if the generation of gravity has nothing to do with the curvature of space-time, then it can only mean that the existence of gravity causes the bending of space-time.

The corners of Pang Xuelin's mouth curled slightly.

"Level 2 Civilization Test Question No. 3: Please briefly describe the basic structure of the Sagittarius A black hole."

“……”

Pang Xuelin was speechless.

Sagittarius A is a galactic black hole, and at the current level of astronomical observation of the Earth, there is no way to effectively observe Sagittarius A.

“PASS！”

"Level 2 Civilization Test Question No. 3: Please give an accurate mathematical model of the sun."

“……”

“PASS！”

"Level 2 Civilization Test Question No. 4: Please give a map of the distribution of mineral resources in the solar system."

“……”

“PASS！”

……

Pang Xuelin was speechless, and the next dozen or so questions were either astronomical problems beyond the ability of human beings to observe and explore, or various problems beyond the scope of human current scientific research.

There are many concepts that Pang Xuelin has never heard of at all.

Soon, Pang Xuelin realized that the other party was afraid that he would guess his thoughts, so he used this method to hide some scientific and technological information with extremely high strategic value.

After the fifteenth question was over, Pang Xuelin said: "Forget it, terminate the second-level civilization testing procedure, I want to meet you." You almost destroyed the solar system in order to build the Great Wall of Stars, and you brought me here, you have to give me an explanation. ”

The digital space is quiet again.

This time, the other party's reaction was faster than Pang Xuelin imagined.

About a minute later, in front of Pang Xuelin, an old man with a human figure suddenly appeared.

The old man stepped forward and waved his hand gently.

Soon, a table and two rattan chairs appeared in the space.

There were even two cups of steaming green tea on the table.

"Mr. Pang Xuelin, hello, I am the Chief Archon of the Galactic Carbon-Based Life Alliance, and in your language, it should be called - Maweisha Mabukodas Drakel."

"I'll call you Your Excellency the Archon, hello! You just said my name accurately, you should have checked my identity on Earth, right? ”

The archon nodded, "Mr. Pang, first of all, I apologize to you, in order to stop the Silicon Alliance from counterattacking, we have to destroy a large number of stars in this area. However, since it has been determined that there is a first-level civilization on the earth, instead of destroying the solar system, we will also include this star field in a protected area, strictly prohibiting the entry of advanced civilizations from the outside world. ”

As he spoke, the old man said again, "Mr. Pang, let's sit down and talk." ”

Pang Xuelin smiled, sat down opposite the old man, picked up the teacup on the table and took a sip gently, the tea was fragrant, and there was basically no difference in the taste of green tea drunk on the earth.

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