Siheyuan (traditional courtyard house): Starting with the Korean War, returning home to take charge

The meeting room was filled with an overwhelming smell of smoke.

He Yuzhu stood in front of the blackboard, twirling the chalk in his hand twice without writing. Below him sat Director Sun of the Fifth Academy of Aerospace Science and Technology, Researcher Wang from the Institute of Physics, Chinese Academy of Sciences, and several young experts. Director Sun opened his notebook, the pen tip touching the paper, but he didn't move. Researcher Wang's reading glasses perched on his nose, the lenses reflecting the ceiling light, obscuring his eyes. A young man behind him tried to raise his hand several times, then withdrew it.

He Yuzhu pressed the chalk onto the blackboard and began to draw. An oval, with several curved lines around it, denser at the front and sparser at the back. He drew slowly, as if recalling something. When he finished, he stepped back, chalk dust falling onto his sleeve, but he didn't brush it off.

"Warp propulsion. The spaceship remains stationary; it is space that moves. It compresses the space in front and expands the space behind, keeping the spaceship inside a bubble and being propelled by space."

Researcher Wang took off his glasses and wiped them with the corner of his shirt. He glanced at Dean Sun, who was looking down, writing a few words in his notebook, then crossing them out. Researcher Wang put his glasses back on and cleared his throat.

"Director He, what you're talking about is called the Alcubely drive. I've seen the paper; it was published in 1994, and it's still just a mathematical model. How come you..." He didn't finish his sentence, swallowing the rest.

He Yuzhu turned around, picked up the stack of documents wrapped in kraft paper from the table, untied the rope, pulled out the first drawing, and used a magnet to stick it to the blackboard. The drawing was covered with dense contour lines, concave in the center and convex at the edges, like an inverted pot.

"The mathematical model of a curvature bubble. The space compression ratio is 20:1, and the expansion ratio is 20:1. The spaceship stays inside the bubble, stationary, while space moves at ten times the speed of light."

The room fell silent. Dean Sun looked up at the blueprint, his lips moved slightly, but he didn't utter a sound. Researcher Wang stood up, walked to the blackboard, leaned closer to look, then stepped back two paces, squinting. He took off his glasses and pinched the bridge of his nose.

"Where does it grow? This energy requirement... negative energy density, how do you plan to generate it?"

He Yuzhu walked to the window and opened it. The wind outside blew in, making the papers on the table rustle. He stood there, his back to the people inside.

"The Casimir effect. In parallel plates at the nanoscale, vacuum fluctuations are suppressed, resulting in negative energy density. This is exactly what Qian Zhiyuan's carbon nanotubes can do."

Researcher Wang paused for a moment. He turned around and looked at the group of young experts behind him. One of the bespectacled young men nodded slightly, while another frowned and scribbled something rapidly on a piece of paper. Researcher Wang returned to his seat, sat down, and asked no further questions.

Dean Sun spoke. His voice was soft and hesitant.

"Director He, we in the aerospace industry know the difficulties of spacecraft. Current spacecraft take six months to reach Mars and ten years to reach Pluto. What you're talking about, if it works, could reach Mars in just a few days. But this approach..." He paused, tapping his fingers twice on the table, "...is too difficult."

He Yuzhu turned around and looked at Dean Sun. He didn't speak immediately, but took out a cigarette from his pocket, lit it, and took a puff. The smoke slowly dissipated in front of the window.

"Fifty years ago, nuclear fusion was science fiction. People wrote novels and made movies, all saying it was impossible. Now we've done it, with a Q value of 5.2, and it ran stably for 300 seconds."

He paused, then stubbed out his cigarette on the windowsill.

"Someone has to walk this path. If we don't, no one else will. The Americans won't, the Soviets won't. If we do, we'll be the first."

Dean Sun lowered his head and wrote a few words in his notebook. This time, he didn't cross them out.

Researcher Wang stood up again. He walked to the blackboard, picked up the chalk, and wrote a formula next to the diagram of the curvature bubble: Einstein's field equations, curved spacetime. He wrote slowly, his fingers trembling slightly.

"Where does it grow? This negative energy density, the theoretical value... is too high. Can carbon nanotubes be produced in such large quantities?"

He Yuzhu walked back to the front of the blackboard, took the chalk from his hand, and wrote a number under the formula. It was very small, very small.

"One cubic millimeter can generate the same amount of negative energy as... the mass of a few drops of water."

Researcher Wang stared at the number for a long time. He put down the chalk and dusted off his hands.

"Give it a try."

The room fell silent again. Dean Sun closed his notebook, stood up, walked to the window, and looked at the hazy sky outside. The young experts began to whisper among themselves; one said, "The energy density is insufficient," and another said, "But the theory is feasible." The young man with glasses raised his hand, and He Yuzhu nodded.

"Where does the curvature bubble grow? It's a problem of stability. If space compression is uneven, the spaceship will be torn apart."

He Yuzhu pulled another drawing from the documents and pasted it on the blackboard. It was a structural diagram, with several nested curved surfaces, like an onion.

"Multi-layer curvature bubble. The inner layer is stable, and the outer layer is driven. The tearing problem can be solved."

The young man stood up, walked to the front of the blackboard, looked at it for a long time, then turned around and nodded to Researcher Wang. Researcher Wang didn't say anything, but simply took off his glasses and put them back on.

The meeting lasted three days. He Yuzhu sat in the conference room from morning till night every day, listening to their arguments. On the afternoon of the second day, when the argument was at its fiercest, Researcher Wang slammed his fist on the table, and Dean Sun almost smashed his cup. On the third day at noon, the food delivered from the cafeteria remained untouched, left to cool on the table. It wasn't until the afternoon of the third day that the proposal was barely approved.

It was already dark when the meeting ended. He Yuzhu was the last to leave the meeting room. The lights in the corridor were on, blindingly white. He didn't go back to his office; instead, he stood by the window at the end of the corridor and lit a cigarette. The courtyard downstairs was empty, the streetlights illuminating a few leafless trees, their shadows trailing on the ground. He finished his cigarette before turning to walk back.

Lin Jianguo was waiting for him at the office door. He was holding a notebook with the corners rolled up.

"Dean, Starship Six is ​​running out of memory for warp drive calculations. One model took a week to run, and it crashed halfway through."

He Yuzhu pushed open the door, walked in, and sat down in a chair. Lin Jianguo followed him in and stood in front of the table.

"What do you need?"

"Memory will be increased fourfold, hard drive capacity tenfold, and the processor architecture will be upgraded. At the Shanghai Radio Factory, the 45-nanometer lithography machine can produce new chips, but the design needs to be changed and the process adjusted. It will take at least six months."

He Yuzhu leaned back in his chair, staring at the ceiling. One of the light bulbs was broken, flickering on and off.

"Six months from now, I want to see Galaxy VI running warp drive."

Lin Jianguo nodded, turned, and left. He Yuzhu sat alone in his office, taking the list out of his drawer. He turned to the page on "Warp Drive" and wrote in the blank space: "Joint research by the Fifth Academy of Aerospace Science and Technology and the Institute of Physics, Chinese Academy of Sciences. Galaxy VI needs an upgrade: memory quadrupled, hard drive tenfold, six-month target."