Five years have passed in a flash.

In the past five years, the Earth has completed four orbital flights around the Sun, the eccentricity of its orbital elliptical orbit is increasing year by year, and the aphelion of the Earth's orbit is close to the orbit of Mars.

Due to the massive mass of the Earth, the thrust of the planetary engines is still quite limited, and there is no way to directly push the Earth out of the solar system.

Therefore, before leaving the solar system, the Earth orbits the sun twelve times.

Driven by planetary engines, the eccentricity of the Earth's orbit is increasing year by year.

Eventually, the Earth's aphelion will approach Jupiter's orbit, and then, with the help of Jupiter's gravitational slingshot effect, it will accelerate one last time until it exceeds the third cosmic velocity (where the third cosmic velocity refers to the speed of the Earth itself around the Sun plus the third cosmic velocity), thus breaking free from the gravitational constraints of the Sun.

This part of the journey is known as the orbit change acceleration stage, and it is also a key point in whether the Earth can escape the range of the sun's helium flash.

The Earth's orbit change accelerates year after year, and every time the Earth approaches perihelion, the hearts of humans tighten, and rumors spread in the dungeons that a helium flash burst of the sun is coming.

It is not until the earth falls again towards aphelion that the human heart gradually relaxes.

It's like a Russian gamble on a cosmic scale, rising to aphelion is like a revolver spinning its wheel, and entering perihelion is like pulling the trigger.

But in essence, there is no difference between the two, on the contrary, when the helium flash of the helium flash erupts at aphelion, the temperature of the dungeon will not rise instantly, but slowly heats up, and that feeling is not as good as being vaporized instantaneously at perihelion.

Pang Xuelin doesn't have any special feelings, anyway, whether it is in the novel or the movie, the final ending of the earth is a successful escape, but the process is a little more difficult.

In the past five years, he has grown from a young genius scholar to an academician of the Chinese Academy of Sciences, and at the same time serves as the vice president of Jiangcheng University.

In the world of the Wandering Earth, the government, the military, and the scientific committee are three-legged, and any decision made by the government and the military must be reviewed by the scientific committee.

Therefore, in this world, Pang Xuelin's personal status and personal power are far higher than him in the real world.

But it didn't mean much to him, he wasn't a power-hungry man.

Most of his time, he still rotates between the laboratory, the classroom, and his home.

Yao Bingxia has graduated from high school, and to Pang Xuelin's surprise, this girl was influenced by him during the college entrance examination and chose Jiangcheng University to major in materials science.

However, it is understandable that since the outbreak of the solar crisis, fields such as culture and art have been compressed to the extreme, even religion has disappeared overnight, and science and technology have been elevated to unprecedented heights.

So when he was in school, there was often an extra follower behind his buttocks, and most of the teachers and students in the school knew the relationship between the two, and sometimes when he met Du Jiaxiang, who had already served as the principal of Jiang University, the other party would jokingly ask Pang Xuelin when he would be able to drink the happy wine of the two.

At this time, Pang Xuelin could only talk about him in embarrassment, but Yao Bingxia would sweetly reply that it would be okay when she graduated.

The most unexpected thing is Du Jiaxiang's student Gao Tianyi, who did not choose the academic circle after graduation, but entered the political world, and is now one of the several main leaders of the Jiangcheng No. 1 Dungeon Management Committee.

That afternoon, Pang Xuelin came home from work and opened the door, only to find that the room was pitch black.

Pang Xuelin was slightly stunned, the light in the corridor was still on when he entered the door just now, he thought that the electricity at home had tripped, and he was just about to go to the electric switch room to have a look, when a burst of fragrant wind suddenly came from behind him, and then, a warm body leaned on his back and covered his eyes with his hands.

"Brother Xiaolin, guess what day it is, there is a surprise if you guess!"

Yao Bingxia exhaled in his ear like a landoux.

Pang Xuelin coughed dryly, barely suppressed the strangeness in his heart, and said: "Xiao Xia, don't make trouble, today is Arbor Day on March 12, which is neither your birthday nor a special holiday......"

"Hmph, sure enough, you forgot your birthday again!"

Smack-

The lights in the room turned on, and then, all kinds of streamers fell from the air, Yao Bingxia let go of his hands, walked to the front of Pang Xuelin, and said with a sweet smile: "Brother Xiaolin, happy birthday!" ”

In the past five years, the originally young little girl has completely changed her appearance, with red lips and bright teeth, green and cloudy silk, and eyes as bright as autumn moons, even if she has been with Yao Bingxia for so long, Pang Xuelin is still sometimes shocked by her beauty.

In Jiang University, Yao Bingxia is a well-deserved school flower, but because of Pang Xuelin's relationship, no one dares to pick this delicate flower easily.

"Brother, you come with me."

Yao Bingxia pulled Pang Xuelin into the living room, looking at the cake on the coffee table, Pang Xuelin couldn't help but be taken aback.

"Where did you get this cake?"

In this era, milk is a luxury, not to mention cream, and food such as cakes is a luxury among luxury, and Pang Xuelin has also seen it at the dinner scene of some major events.

Yao Bingxia smiled and said, "I did it myself, don't we have a quota of five liters of fresh milk every month?" If you don't drink it, I saved up milk for three months, and then went to the teacher in the food engineering laboratory and used the centrifuge in their laboratory to make cream, and I entrusted Brother Gao to help me get the eggs, a total of eight, which can be bought in the fruit market, but strawberries and kiwifruits are more difficult to buy, and it is said that people in the agricultural area secretly planted them, and they are currently only sold on the black market, and it took me a full five hundred credits to get them! ”

"You girl......"

Pang Xuelin was moved and sad at the same time, and said: "Xiao Xia, if you really want to eat cake, tell me, I still have a way to get it, do you need to spend so much effort?" ”

Yao Bingxia smiled and said: "In previous years, you gave me a birthday, which time didn't you ask grandpa to tell grandma, sold countless faces to get a cake, when you celebrate your own birthday, you just casually put a bowl to pay for the past, this year I thought I want to make a cake for you by myself, I still found the tutorial of making a cake from the Internet, it is the information of the golden age, I don't know how many years ago, I didn't expect it to be successful once!" ”

Pang Xuelin reached out and touched Yao Bingxia's head, Yao Bingxia's eyes narrowed slightly, and there was an expression of enjoyment on his face.

This is Pang Xuelin's small gesture to show her intimacy, from the day they entered the dungeon to live together, the two have long had a tacit understanding.

"Brother, okay, let's blow out the candles and make a wish first!"

The raw materials of the cake are limited, Yao Bingxia is not big, and he can't put down twenty candles, so Yao Bingxia lit one, which means that Pang Xuelin is one year older.

Whew-

In Yao Bingxia's bright birthday song, Pang Xuelin blew out the candle in one bite.

"Brother, make a wish, make a wish!"

Pang Xuelin said: "Let's make a wish together, okay?" ”

"Good!"

Pang Xuelin closed his eyes, whispered silently in his heart for a while, and then opened his eyes, and saw Yao Bingxia looking at him with a smile.

"Brother, what did you wish?"

Pang Xuelin smiled: "I hope that our Xiaoxia can be happy for the rest of his life and find a wishful husband as soon as possible, so that I can rest assured." ”

"Hmph, I don't want it, I want to be with Brother Xiaolin for the rest of my life, besides, the Ruyi Langjun I want, someone doesn't know."

Yao Bingxia pouted.

"Uh......"

The atmosphere in the living room is awkward.

Pang Xuelin has a headache, this girl doesn't know what's going on, since she was eighteen years old, she has shown a special emotion to herself that surpasses the normal brother-sister relationship.

Pang Xuelin didn't know what Yao Bingxia meant, but he couldn't stay in this world forever, the two would be separated sooner or later, so he had to pretend to be ignorant.

As a result, this girl is now becoming more and more excessive.

"Come, eat cake and eat cake!"

Pang Xuelin hurriedly cut the cake into pieces.

"Humph, coward!"

Yao Bingxia took the cake handed over by Pang Xuelin, and then took a big bite viciously, as if venting some kind of resentment in his heart.

Pang Xuelin had no choice but to pretend to be ignorant.

After a while, Yao Bingxia seemed to be almost angry, and said with a smile: "By the way, brother, there is something I didn't discuss with you, I made a decision in private, I told you, you shouldn't be angry!" ”

Pang Xuelin was slightly stunned and said, "What's the matter?" ”

Yao Bingxia said: "Isn't the coalition government going to resume the Olympic Games that have been interrupted for more than 40 years? I signed up for an electric sled rally from Shanghai to New York! ”

Pang Xuelin said while eating the cake: "It's good, this event is okay, I support you to participate." ”

Yao Bingxia smiled and said: "But I applied for the mixed doubles event, and I couldn't find a suitable teammate, so I added your name!" ”

"What?!"