The Science Fiction World of Xueba

Under the cover of several F-22 fighter jets, the huge Boeing 747 slowly landed at the Galapagos Islands Transit International Airport.

Before landing, Pang Xuelin specially asked the pilot to circle the sky of Xinghuan City several times to observe this city of his own.

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

Looking down from the plane, the natural lake formed by the crater is like the jasper inlaid on the top of the volcano, crystal clear and shining.

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

But after entering the city, you can see a large area of ​​green around the building complex.

The entire city covers an area of ​​more than 20 square kilometers. At present, only the central business district, cultural and educational district, leisure and entertainment district, and residential district are planned. In the future, industrial districts, agricultural districts, etc. will be further planned.

Pang Xuelin's goal is to make Star Ring City self-sufficient in most areas before the Great Depression comes.

The Boeing 747 slowly landed at Transit International Airport.

When Pang Xuelin got off the plane, he saw a red carpet at the airport. Hundreds of representatives from all walks of life in Xinghuan City were organized to welcome him.

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

Among the welcoming crowd, Pang Xuelin unexpectedly saw Ding Yi and the physicist named Baker whom he had met during his lecture.

After the welcoming ceremony was over, Pang Xuelin boarded a bulletproof vehicle and headed for Xinghuan City under the escort of a large number of guards.

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

Kantor arranged for Pang Xuelin to live in a large villa area in the Cultural and Educational District. According to Kanter, the villas are populated by top scientists dug from various countries to the Xinghuan Institute for Advanced Study.

Pang Xuelin's home in Xinghuan City is in Villa No. 1 in this villa area.

In the next few days, Pang Xuelin visited Xinghuan City accompanied by Kanter during the day, and met with the heads of the city hall, police station, court, National People's Congress and other institutions one by one.

back home at night,

Then I started to read 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 papers from the Institute of Theoretical Physics.

At present, there are more than 500 physicists in the Institute of Theoretical Physics of the Starlink Institute for Advanced Study. Except for those physicists who have changed careers, all physicists who have made a little progress in the field of theoretical physics around the world are drawn into it. The Star Ring Institute for Advanced Study.

In the past five years, these physicists have not been idle, but have opened up their brains and constructed some new physical theories through various brainstorming.

Some of them are rehash, but also some very original ideas.

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

Tachyons are not a new concept.

According to the special theory of relativity, in order to keep the speed of light constant, the transformation between the reference systems is the Poincaré transformation, and the commonly used Lorentz transformation is essentially a special kind of Poincaré transformation.

If the "single particle state" is regarded as some kind of object. If these objects are "single particle state" in different reference systems, then these "single particle states" must have some common points.

Mathematically, this is finding irreducible representations of the Poincaré group, and classifying them.

People finally found such two invariants: p^2=guvp^up^v and the sign of p^0, where p is the momentum four-vector.

Classify single-particle states according to these two invariants, and the result will be six kinds of single-particle states, which are positive energy state with mass, negative energy state with mass, positive energy state with zero mass, and negative energy state with zero mass. Energy state, virtual mass state and vacuum state.

Virtual mass particles are so-called tachyons.

The existence of tachyons is entirely produced by the mathematical structure of the Poincaré transformation, but in the final analysis, it is still caused by the principle of the constant speed of light.

In the light cone of the full momentum space, it is called the time-like space, and the time-like space corresponds to the states with mass. These states are always in the light cone, and the speed is always smaller than the speed of light.

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

The space outside the light cone is called space-like space, corresponding to the virtual mass states, these states are always outside the light cone, and the speed is greater than the speed of light.

Because of this, in the theory of relativity, the existence of super-light speed is not prohibited, but only "beyond" the speed of light is prohibited.

The former refers to the state where the speed is greater than the speed of light, and the latter refers to the process of accelerating from sub-light speed to super-light speed.

That is to say: the sub-light speed is always sub-light speed, and the super-light speed is always super-light speed.

The real ordinary matter is sub-light speed, so it is usually said that the speed of light is the upper limit of the speed in nature.

If substances such as tachyons are also included, it is more general to say that the speed of light is a barrier or barrier of speed.

That is to say, 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 exceed the speed of light upwards.

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

But so far, tachyons are only theoretical hypothetical substances, and there is no experimental evidence so far.

Even in the Three-Body Trilogy, there isn't any description of tachyons.

Pang Xuelin personally prefers that tachyons do not exist in this universe.

After finishing this thesis, Pang Xuelin just opened a new thesis document on the computer, and was about to continue to do so when there was a sudden sound of footsteps behind him.

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

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

Pang Xuelin took the milk from Cheng Xin, thanked him, drank most of it in one gulp, and said, "I'll go to bed after finishing this paper, you go to rest first!"

"No, I won't sleep until you sleep!"

Cheng Xin shook her head, and sat down on the side sofa.

Now Cheng Xin has almost become Pang Xuelin's big housekeeper. She will take care of everything from work schedules to basic necessities.

Pang Xuelin smiled, ignored her, clicked on the paper and continued reading.

This paper is very interesting, discussing dark matter and dark energy.

The author believes that dark matter is just the projection of four-dimensional objects in three-dimensional space, so we cannot observe its existence, but we can feel its gravity.

Dark energy is the projection of the five-dimensional space-time in the four-dimensional space-time, which endows us with cosmic repulsion, which leads to the accelerated expansion of the universe.

Pang Xuelin's eyes narrowed slightly. In Three-Body, although the author did not explicitly explain the existence of dark energy and dark matter, he hinted that dark matter is actually a two-dimensional object that has been hit by dimensionality reduction and appears in the three-dimensional universe. gravity.

This is similar to the explanation in this paper.

Pang Xuelin turned the paper to the front page, and looked at the author's name, and found that he was an old acquaintance.

Boyle Baker, a student of Edward Witten, had met him some years earlier when he had given his famous lecture in physics.