The massive Boeing 747, backed by several F-22 fighter jets, slowly landed at the Galapagos Islands Star Ring International Airport.

Before landing, Pang Xuelin specially asked the pilot to go around the Star Ring City several times to observe this city of his own.

Star Ring City is located in the southeastern plains of Isabela Island, with Mount Azul at an altitude of more than 1,600 meters to the west and Mount Negra to the north.

Viewed from the plane, the natural lake formed by the crater resembles jasper embedded in the summit of the volcano.

Around the volcano, the rugged surface is filled with dark red eruptions.

But as soon as you enter the city, you can see a large area of greenery around the complex.

The whole city covers an area of more than 20 square kilometers, and only the central business district, cultural and educational district, leisure and entertainment area and residential area are planned at present, and further industrial areas, agricultural areas and so on will be planned in the future.

Pang Xuelin's goal is to make Star Ring City self-sufficient in most fields before the great trough comes.

The Boeing 747 slowly landed at Transwarp International Airport.

When Pang Xuelin stepped off the plane, he saw that the airport was covered with a red carpet, and hundreds of representatives from all walks of life in Star Ring City were organized to welcome his arrival.

Under Kante's introduction, Pang Xuelin shook hands with these people one by one.

In the crowd of greetings, Pang Xuelin actually saw Ding Yi and the physicist named Baker he met when he was giving a lecture.

At the end of the welcome ceremony, Pang Xuelin directly boarded a bulletproof car and went to Star Ring City under the escort of a large number of guards.

The first phase of the Star Ring City project has not yet been completely completed, and buildings under construction can still be seen on the road from time to time.

Kantor arranged a large villa for Pang Xuelin in the cultural and educational district, and according to Kanter, the villa was inhabited by top scientists from various countries who had been recruited to the Star Ring Institute for Advanced Study.

Pang Xuelin's home in Star Ring City is in the No. 1 villa in this villa area.

In the next few days, Pang Xuelin visited Star Ring City during the day, accompanied by Kanter, and met with the heads of the city hall, police station, court, people's congress and other institutions one by one.

When I got home in the evening, I began to brush up on the more interesting papers of the Transwarp Institute for Advanced Study in the past few years.

The first thing Pang Xuelin read was naturally the paper of the Institute of Theoretical Physics.

At present, there are more than 500 physicists in the Institute of Theoretical Physics of the Transwarp Institute for Advanced Study, and in addition to those physicists who have changed careers, all physicists from all over the world who have made a little achievements in the field of theoretical physics have been pulled into the Transwarp Institute for Advanced Study.

In the past five years, these physicists have not been idle, but have opened their brains and brainstormed to construct some completely new physical theories.

There are a lot of old tunes that go back to them, but there are also some very new ideas.

For example, Pang Xuelin is reading this paper explaining the "tachyon universe".

Tachyon is not a new concept.

According to the special theory of relativity, in order to satisfy the constant speed of light, the transformation between reference frames is the Poincaré transform, and the commonly used Lorentz transform is essentially a special class of Poincaré transforms.

If you think of a "single particle state" as some kind of object. If these objects are "single-particle states" in different frames of reference, then these "single-particle states" must always have something in common.

Mathematically, this is to find irreducible representations of Poincaré groups and classify them.

Two invariants were eventually discovered: the sign of p^2=guvp^up^v and p^0, where p is a momentum quad vector.

According to these two invariants, the classification of single-particle states results in six single-particle states, which are positive energy states with mass, negative energy states with mass, positive energy states with zero mass, negative energy states with zero mass, virtual mass states and vacuum states.

Imaginary particles are called tachyons.

The existence of tachyons is entirely due to the mathematical structure of the Poincaré transformation, but in the end, it is due to the principle that the speed of light does not change.

Within the cone of light in the full-momentum space, it is called the time-like space, and the time-like space corresponds to the states with mass, which are always within the light cone and the speed is always less than the speed of light.

The light cone is called the light-like space, which corresponds to the massless states, which are always on the light cone and the speed is always equal to the speed of light.

The outer cone of light is called empty space, which corresponds to imaginary mass states, which are forever outside the cone of light and have a velocity greater than the speed of light.

Because of this, in the theory of relativity, the existence of superluminal speed is not prohibited, but only "exceeding" it.

The former refers to a state in which the speed is greater than the speed of light, and the latter refers to the acceleration from sub-light to superluminal speed.

That is, the so-called: the sub-light speed of the eternal sub-light speed, the superluminal speed of the eternal super-light speed.

Real ordinary matter is sub-light-speed, so it is usually said that the speed of light is the upper limit of nature's speed.

If we include substances such as tachyons, it is more common to say that the speed of light is a barrier or barrier to speed.

That is, ordinary matter: the mass is a real number (the square of the mass is a positive number), the speed is lower than the speed of light, and it can never go upwards beyond the speed of light.

Tachyon matter: Mass is an imaginary number (the square of mass is negative), faster than the speed of light, and can never descend to the sub-light speed.

However, so far, tachyon is only a theoretical hypothetical substance, and there is no experimental evidence so far.

Even in the Three-Body Trilogy, there is no description of tachyon.

Pang Xuelin is personally inclined to say that tachyons do not exist in this universe.

After finishing this paper, Pang Xuelin had just opened a new paper file on the computer, and was about to continue brushing, when there was a sudden sound of footsteps behind him.

Pang Xuelin turned his head and saw Cheng Xin coming over with a glass of warm milk.

"Professor Pang, it's half past eleven, it's almost time for you to rest!"

Pang Xuelin took the milk from Cheng Xin's hand, thanked him, drank most of it in one gulp, and then said: "I'll sleep after reading this paper, you go to rest first!" ”

"No, I'll sleep again when you sleep!"

Cheng Xin shook his head and sat down on the sofa beside him.

Cheng Xin has almost become Pang Xuelin's housekeeper now, from her work schedule to her food, clothing, housing and transportation, she will ask about them one by one.

Pang Xuelin smiled, didn't care about her, clicked on the paper and continued to read.

This paper is very interesting and explores dark matter and dark energy.

The author argues that dark matter is just a projection of a four-dimensional object in three-dimensional space, so we cannot observe its existence, but we can feel its gravitational pull.

Dark energy, on the other hand, is the projection of the five-dimensional space-time in the four-dimensional space-time, which gives us the repulsive force of the universe, which causes the universe to expand at an accelerated pace.

Pang Xuelin's eyes narrowed slightly, in the Three-Body Problem, although the author did not clearly explain the existence of dark energy and dark matter, there was a hint that dark matter is actually a two-dimensional object after being hit by dimensionality reduction, and the gravitational force presented in the three-dimensional universe.

This is similar to the explanation of this paper.

Pang Xuelin flipped the paper to the front page and looked at the author's name, which turned out to be an old acquaintance.

Boyle Beck, a student of Edward Witten, whom he had met a few years earlier in his famous lecture in physics.