Chapter 35: Hard to Mask the Excitement

Information in China is not as restricted as the outside world assumes, especially in a place like Beijing. People here are far from being cut off from the latest scientific developments, nor are they solely dependent on second-hand information filtered through the Soviet Union.

The Manhattan Project, however, was over a decade old, and given its direct link to the surrender of Japan, it was impossible for the Chinese side not to be aware of it. Upon hearing the terms "atomic bomb" and "Manhattan Project," the middle-aged man immediately grasped their significance and wondered if they could assist the ongoing Project 596. While Qian Xuesen’s DF-series intercontinental missiles were certainly vital, Project 596 was currently China’s most critical endeavor. He could hardly suppress his excitement; he understood all too well the situation China faced and what the possession of an atomic bomb would mean. At the very least, it would grant China significant leverage in border negotiations with the Soviets, rather than the passive position they currently held.

"That's right. If my judgment is correct, this is the Monte Carlo method. Professor Lin has concealed it within the application of high-dimensional integration."

Qian Xuesen paced back and forth in the spacious room, smoking, unable to hide his agitation. In China today, one might learn of such a method through academic journals, but the specific details remained elusive. Furthermore, even if one understood the algorithm, the country lacked the computers necessary to implement it. The hardware gap was simply too vast, so there had been little incentive to master it. Yet, this improved Monte Carlo method was a timely blessing for China.

"You see, its application is incredibly broad; it can assist the entire R&D process of a nuclear bomb. The core challenge of an atomic bomb lies in determining the critical mass of nuclear materials—such as the minimum quantities of Uranium-235 or Plutonium-239—as well as how neutrons diffuse, reflect, and trigger chain reactions within fissile materials. In the past, we could only rely on the Boltzmann equation and trial-and-error experiments, which were costly and time-consuming."

"Now, we can simulate high-probability neutron paths using simplified geometric models. Look, Professor Lin’s introduction of pseudo-random numbers here significantly reduces the total computational load. I worked with von Neumann and saw his random number generator; how could I have failed to realize that pseudo-random numbers could be used to simulate neutron reflection frequencies in different reflective layers? I finally understand why the Soviet Union’s atomic bomb test succeeded four years ahead of schedule. They must have possessed the complete Monte Carlo algorithm."

The middle-aged man listened, stunned. Was it really that powerful? Could it save four years of time?

"Director Qian, are you saying that if we master the Monte Carlo method, we can also save four years?" The man's voice trembled. A thought struck him: "No, we must redouble our efforts to persuade him to return! Losing such top-tier talent overseas is a massive blow to us."

Qian Xuesen did not answer him directly, continuing instead: "I don't know exactly how much time we can save, but we can certainly drastically reduce the number of nuclear explosion experiments. By building Monte Carlo models and using pseudo-random number generators to decrease the computational burden, we can perform multiple samplings of neutron lifespans, collision probabilities, and spatial distributions to rapidly estimate critical thresholds for different material configurations. We could reduce the number of tests required for nuclear materials from dozens down to single digits."

"We must organize experts in mathematics to analyze this immediately and report the findings to the Project 596 team. We cannot waste a single minute! There are 37 cases here; we must pool the strength of all our experts. The Monte Carlo method isn't just for atomic bombs; it can also be applied to the development of the DF-1. We can use it to create errors, optimize the missile's redundant structures and warhead design, and improve its accuracy. We previously aimed for an accuracy within 3,000 meters, which everyone knows is quite poor. We were essentially modeling our work on Soviet P-2 technology—training our teams rather than true design—resulting in a significant gap between the DF-1 and practical application. But with the Monte Carlo method for structural adjustments, I am confident I can bring that accuracy within 1,000 meters."

This was no exaggeration. The original DF-1 had no future after its test flight because of its inherent flaws; China had developed it primarily to train personnel. It wouldn't be until the DF-2 that large-scale deployment began.

The middle-aged man exhaled a long breath, knowing the weight of the pressure they were under. "It seems the threat from the Soviets might be neutralized. Director Qian, how soon can the improved DF-1 be test-fired?"

The decision to officially deploy the DF-2 was made two months later, by which time China knew the Soviets had unilaterally torn up their cooperation agreement and that all 1,390 experts would be withdrawn.

"Six months. At most six months. In six months, we will complete the test flight of a combat-ready DF-1!" Qian Xuesen was well-versed in the internal reports and understood the current situation. Under these circumstances, if for no other reason than to prove a point, who cared if the Soviet experts were gone? Who cared if they held back their secrets? They would still build a better missile than the P-1.

He interrupted himself: "But I have a feeling Professor Lin has given us another surprise. I won't be certain until Xiao Zhang brings back my notebook. I have a hunch that if I substitute my data into this formula, I will get the result I've been looking for."

Qian Xuesen walked to the blackboard. Twelve panels covered an entire wall, arranged in a four-by-three grid. He used a pulley system to slide the boards, moving the section he wanted to the bottom. The sound of the pulleys sliding along the tracks was sharp in the late-night office building, but no one present found it grating. Instead, they hoped Qian Xuesen would find something within those dense, complex formulas.

"Director, I’ve brought it!" Zhang Kewen arrived at the office building, breathless. He hadn't wasted a second, traveling by car and then running the rest of the way.

Qian Xuesen lunged forward, snatched the notebook from Zhang’s hand, and flipped through it until he found the page he needed. He stood before the blackboard he had just lowered, staring intensely, his brows furrowed, his hands calculating frantically in the notebook.

"Yes! This is it! Just as I expected—Professor Lin’s set of linear equations truly contains this information!"