Rebirth: Starting from Lighting Up the Tech Tree

Chapter 220 Quantum Branches

Three days after the German team's paper was published online, Zuo Cheng received a system notification in his office.

It wasn't a notification on a tablet. It was fluorescent text that appeared directly in my consciousness, the color of the tech tree interface.

The conditions have been met. The conditions for activating the eighth branch have been met.

Zuo Cheng put down his pen. The review comments on the screen were still stuck on half a sentence. He slowly leaned back in his chair and took a deep breath.

Then he used his consciousness to open the system panel.

The main trunk of the technology tree slowly emerged from the darkness. Seven activated branches, like seven luminous veins, extended from the main trunk in different directions: communications engineering, aerospace communications, the Internet of Things, AI, unmanned systems, space photovoltaics, and commercial aerospace. Each branch was adorned with luminous leaves, the veins clearly defined, and the energy flow stable.

In the previously empty space on the right side of the main trunk, something was glowing.

It wasn't the brilliance of already activated leaves. It was the light of a tree just breaking through the soil. Cracks appeared on the surface of the trunk, from which a pale blue light seeped. The bark texture of the eighth branch grew from nothing, inch by inch, from the main trunk, like an invisible tree opening up a new direction in the darkness.

The system prompt popped up again. The eighth branch: Quantum Technology. Activation confirmed.

Zuo Cheng's hands rested steadily on the table. But in his mind, he was intently focused on the technology tree. Seven years had passed, from the first flash of the technology tree he saw when he opened his eyes in his dormitory on the day of his rebirth, to now, the bark texture of the eighth branch breaking through the soil. Seven years, eight branches. Each time felt like lighting a new lamp in his heart.

The first leaf lit up. The foundations of quantum computing. Quantum bit manipulation, quantum gate operations, quantum entanglement—all the fundamental principles of quantum computing were infused into his consciousness at this moment as a complete knowledge system. Not definitions from textbooks, but a complete understanding growing directly from the underlying logic of quantum mechanics.

Then came the second one. Quantum communication. Quantum teleportation, quantum key distribution, quantum repeaters. He had read papers on these theories in his previous life and verified them with Tianyan in this one. But the moment the leaf lit up, they were no longer separate technical points in his mind, but rather a continuous vein on a whole branch.

The third one. Quantum encryption. The fourth one. Quantum simulation. The fifth one. Quantum machine learning. The sixth one. Quantum optimization. The seventh one. Quantum sensing. The eighth one. Quantum materials.

The eight leaves lit up one by one, like piano keys being struck from low to high notes by unseen fingers. Each lit leaf carried a soft sound from the depths of consciousness, like a bubble rising from deep water.

The entire branch of quantum technology has been fully activated.

Zuo Cheng closed his eyes. In his mind, the technology tree shone brighter than ever. The eighth branch extended diagonally upwards to the right, its eight leaves gleaming a pale blue light in the darkness. The veins on the leaves were still faintly glowing, seemingly feeding energy back to the main trunk.

The numbers on the system panel started to jump.

Main quest completed. 180 points added.

Zuo Cheng watched as his score jumped from 647 to 827. Seven days ago, when he saw that sphere of light underground in the Taklamakan Desert, he had a premonition that the eighth branch wouldn't be too far away. But what he didn't expect was that the system would display more than just a number.

The technology enhancement level has been increased from 1.4 to 1.5. Cross-branch fusion permissions have been upgraded. Advanced fusion of quantum and arbitrary branches has been unlocked.

Quantum addition of arbitrary branches.

Zuo Cheng stared at those seven words for a long time.

Previously, cross-branch fusion required specific combinations. AI plus communication, AI plus the Internet of Things—each fusion required selecting specific leaf pairs. But now, quantum branches can serve as universal fusion components, directly fusing with any activated branch. Quantum plus AI, quantum plus space photovoltaics, quantum plus brain-computer interfaces, quantum plus commercial aerospace—seven entirely new directions for fusion have opened up.

He didn't try immediately. He put away the system panel and brought his attention back to reality. Outside the office window was the familiar night view of Hangzhou, and the branches of the old locust tree outside the window swayed slightly in the night breeze. It was the same scene as a few minutes ago, but Zuo Cheng knew that something had completely changed.

He picked up his phone and sent Yu Ying a message: "Are you asleep?"

"without."

"Let's get down and walk around."

Three minutes later, Yu Ying arrived at the entrance of the lobby on the first floor. She was wearing a white shirt, and her hair was casually tied up. Seeing Zuo Cheng's expression, she didn't ask any questions, but simply walked over and stood next to him.

The two walked slowly along the path outside the 402 headquarters building. The night breeze blew from the river, carrying the scent of water and plants.

"That's the eighth one," Zuo Cheng said.

Yu Ying paused for a moment, then continued walking.

She knew nothing of the system's existence, but she knew Zuo Cheng wouldn't say such a thing without reason. Seven years ago, Zuo Cheng first told her that things were progressing, and with each step, she would see something different. She asked how many steps there were, and he said twelve. Later, every so often, Zuo Cheng would become exceptionally quiet on certain nights, and the next day she would see him drawing entirely new technical routes on the whiteboard. She gradually understood that those quiet moments were when he was stepping onto a new step.

"How long did it take this time?" she asked.

"It's been almost a year since the quantum computing project was initiated," Zuo Cheng said.

"It's not a matter of speed." Yu Ying looked up at the sparse stars in the sky. "It's that we waited too long between seven and eight."

Zuo Cheng remained silent. He knew Yu Ying never needed him to explain anything. She never questioned what those steps were, nor how those technical routes had appeared out of thin air on the whiteboard. She simply stood beside him each time he stepped onto a new step.

"Is there anything after quantum mechanics?" she asked.

"There are four more," Zuo Cheng said. "All connected together."

Yu Ying tilted her head slightly. "Connected to what?"

Zuo Cheng thought for a moment, then didn't answer. He thought of that door. The icon of the final link in the new quest chain, a door leading to an unknown destination. The Origin Civilization. A seed from four billion years ago. 177 planets sown. The eighth branch was just another step on that door. But he didn't want to talk about it now. Tonight wasn't a night for discussing origins.

The two walked for a long time, until almost all the lights on the office floor were off. When they reached the office door, Yu Ying said something.

"Will you tell me after all twelve branches are activated?"

Zuo Cheng looked at her. "Tell me what?"

"Everything."

Zuo Cheng was silent for a moment. Then he said, "Once all twelve branches are activated, I will tell you everything."

Yu Ying nodded and turned to walk towards the elevator.

Zuo Cheng returned to his office and reopened the system panel. The eight leaves of the quantum technology branch glowed quietly in the darkness. He invoked his civilization perception and saw that the pillar of light in the direction of quantum computing had turned deep purple, and more than a dozen new pillars of light had grown beside it. Quantum chips, quantum communication, quantum sensing—the entire quantum ecosystem was catalyzed as the eighth branch was activated.

Points: 827. Technological advancement: 1.5. Eight branches.

Four are still short of twelve. Four are still short of that door.

He walked to the whiteboard and added three words next to the quantum computing roadmap he had written earlier.

Next step.