"Citizens of Human Federation Underground City 1183, according to the latest observations, the sun will undergo a helium flash in 30 minutes."
"Human civilization has entered its final 30-minute countdown."
"We… have failed."
In the underground city, 500 meters below the Earth's surface, a somber female voice echoed from the ubiquitous loudspeakers.
Everyone who heard the broadcast felt an indescribable sense of suffocation deep in their hearts.
Lü Yongchang sat expressionlessly in front of a holographic projection.
In the hologram, a massive fireball burned quietly in the depths of space.
This was an image of the sun at this very moment.
Lü Yongchang took a deep breath and waved his right hand in the air, making a gesture.
The holographic image suddenly zoomed out, revealing the current state of the solar system.
Unlike the solar system of the past, two planets were now missing.
Venus and Mercury had already been consumed by the sun!
And the sun itself had become a deep red behemoth!
In astronomy, it had a special name.
Red giant!
"Yongchang… are we, no, is humanity, really going to perish like this?"
A slightly helpless female voice came from beside him.
Lü Yongchang turned his head to look.
A woman in a white lab coat sat in a chair, staring blankly at the holographic projection.
Lü Yongchang's eyes flickered slightly.
As the chief scientist of the Human Federation Academy of Sciences, this woman, Su Yutong, was his partner and his right-hand assistant.
"Yes, humanity is finished."
Lü Yongchang sighed softly and continued, "We have about twenty minutes left. Do you want to go to the surface and take a look?"
Su Yutong's eyes flickered slightly. She pulled her gaze away from the holographic projection and slowly stood up from her chair.
She reached up and let down her long, jet-black hair, which had been tied up. Facing Lü Yongchang, she gave him a radiant smile.
"Of course."
…
In the elevator of Underground City 1183, Lü Yongchang and Su Yutong, dressed in heavy protective suits, stood in silence.
The elevator screen displayed the current depth, the numbers constantly changing.
Lü Yongchang's eyes showed a hint of nostalgia.
In the year 2045 of the Common Era, the sun, upon which humanity depended for survival, was affected by unknown forces, ending its prime and prematurely entering its decline.
In just five years, the sun had entered the red giant phase, consuming two planets in the solar system.
Driven to the brink, humanity set aside its differences and established the Human Federation, or "Humanity United" (H.U.).
Lü Yongchang, thanks to his lifelong academic excellence, had fought his way to the top and earned the title of Chief Scientist of the Human Federation Academy of Sciences!
According to his calculations, even though the sun had prematurely entered the red giant phase, it would still take over a hundred years for the helium flash to occur.
Since the surface was no longer habitable, under his leadership, the Human Federation built countless underground cities, and all of humanity took refuge underground while beginning the construction of interstellar spacecraft.
But clearly, he had miscalculated.
In just five years, the sun had traversed a life cycle that would take other stars billions of years!
The helium flash was imminent!
Earth, now the closest planet to the sun, would undoubtedly be melted into a ball of magma.
Human civilization had reached its end!
"Ding!"
"Respected Chief Scientist, may your research mission on the surface be a complete success."
A crisp notification sound pulled Lü Yongchang out of his thoughts.
He looked at the elevator screen.
518°C.
That was the temperature outside.
The elevator doors slowly opened, and a wave of heat accompanied by distorted air rushed in!
Even with the protective suit, Lü Yongchang could feel the intense heat as he looked up at the massive red giant and the boiling surface!
"One more minute, and the helium flash will occur."
Su Yutong's slightly cool voice came through the radio.
Lü Yongchang didn't respond. He simply raised his head and looked at the sun through the filtered visor.
As the only advanced civilization on Earth, he didn't want to bow his head and accept death!
"Do you know how much effort I put into becoming your assistant?"
"Do you know why I did it?"
Perhaps because it was the final moment, Su Yutong's voice was filled with relief. "Because… I like you."
Lü Yongchang's pupils contracted sharply.
The helium flash erupted!
An intense white light burst from the red giant and bathed the Earth!
In an instant, Lü Yongchang lost consciousness.
…
Before his eyes was a fluorescent green void.
A white line slowly extended, drawing a tree-like diagram in the fluorescent green space.
Lü Yongchang looked at everything before him in confusion.
What… what is this?
A faint flash of light appeared at the base of the tree diagram.
Instinctively, he directed his gaze to the bottom of the diagram.
Nuclear Energy Mastery: Controlled Nuclear Fission.
A line of bright white text appeared.
The next moment, the white area began to extend upward.
Nuclear Energy Mastery: Controlled Nuclear Fusion.
As this line of previously dim text brightened, countless words and symbols instantly flooded Lü Yongchang's consciousness!
…
"Lü Yongchang! Lü Yongchang!"
"Professor Guan is calling you! Lü Yongchang!"
In a daze, familiar whispers reached his ears.
His vision gradually focused.
What greeted him was a classroom.
Seeing the elderly man on the podium frowning at him, Lü Yongchang's pupils contracted sharply.
Professor Guan Hualiang!
He… hadn't he passed away five years ago?!
"Lü Yongchang! This is the first university physics class! If you dislike physics so much, why did you enroll in the physics department?!"
Professor Guan's voice was filled with anger.
Lü Yongchang looked around in confusion, instinctively standing up and scanning the room.
The familiar scene.
This was… his university classroom!
If he remembered correctly, this was his first physics class in his sophomore year!
He quickly pulled out his phone from his pocket and turned on the screen.
September 6, 2030!
Had he… had he been reborn?!
In an instant, countless complex emotions flooded Lü Yongchang's mind.
Confusion, sorrow, despair, and a glimmer of hope!
"Destined by heaven, long life and prosperity."
This was the origin of his name.
As it turned out, the name was not a mistake.
In his previous life, he had held the highest position in humanity, but… due to his miscalculations, human civilization had been utterly destroyed.
In this life, he would make up for it all!
But… how?
"Lü Yongchang! Are you listening to me?!"
On the podium, Professor Guan Hualiang's face was red with anger.
In all his years of teaching at Sandao University, he had never encountered such a disrespectful student!
Lü Yongchang looked up at Professor Guan on the podium and the blackboard behind him. His eyes flickered slightly.
Perhaps… he needed a chance to make a stunning impression!
The next moment!
The countless formulas and words brought by the fluorescent green tree diagram swirled like a storm in his mind!
___
¿What is controlled nuclear fission?
To maintain a controlled and sustained nuclear reaction, for every 2 or 3 neutrons released, only one must impact another uranium nucleus. If this ratio is less than one, the reaction will be extinguished; if it is greater than one, it will run out of control (atomic explosion).
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