In fact, Zhu Lingjing didn't know what Zhou Changfeng was referring to specifically, but given the latter's identity, she guessed based on intuition.
This guy must be thinking about weapons, and combined with the mass loss mentioned, he undoubtedly thought of the energy bursting out in this process based on the mass-energy conversion formula E=MC.
Zhou Changfeng, who was full of expectations, immediately nodded and said: "Yes, so based on this discovery, it is theoretically possible to design an extraordinary... bomb."
Your span is too big, why do you suddenly jump to practical applications?
"Wait a minute." Zhu Lingjing was trying to recall the cutting-edge research in physics in the past few years. She vaguely remembered that the academic community seemed to be debating endlessly about this experiment, and always believed that transuranic elements were generated during the process.
Is this article published in Nature reliable? Splitting of the atomic nucleus? This is a bit shocking.
She smiled slightly and said: "Research on the origin of all things is never accomplished overnight. The discoveries in this area are too new and it is not easy to directly apply them to practice. Moreover, the truth or falsehood has not yet been determined. Let's see the reaction of the world's academic community later. "
In the 1930s, it was popular in the physics community to use neutrons to bombard various atomic nuclei to explore the process and results. However, when people used neutrons to bombard uranium nuclei, obvious radioactive phenomena were observed. In fact, nuclear fission occurred, but people mistakenly believed that Some people think that this is just the generation of new substances-transuranic elements.
Therefore, a series of contradictions have arisen in theory, and the academic community is fiercely arguing. Physicists all over the world have repeatedly tried the same experiments, but only today have they finally made a disruptive discovery.
At that time, people's understanding of the world was still limited, and their knowledge of nuclear physics was quite shallow. Their fixed thinking greatly hindered people from getting out of misunderstandings.
In fact, Qian's research team at Hangzhou University and Imperial Gezhi University was already very close to the correct answer in the 36th year of Zhichang. Unfortunately, they were confused by a strange element (an isotope of yttrium) and mistakenly thought that it was also transuranic. elements rather than products of nuclear fission.
Although the famous Fermi Group, Curie Group, and Qian Group all failed, the mystery that caused mankind to stagnate on the path of nuclear physics exploration for four years has finally been solved.
"Okay, but..." Zhou Changfeng thought for a while and said seriously: "Well... if this discovery is correct, I think we should start preliminary research as soon as possible. It is so amazing. The chain reaction and the energy released will be very, very great. many."
"That's a good word, but I feel like it depends on luck, or it must be a try." After dinner, Zhu Lingjing had nothing to do, so she simply continued talking to him.
She blinked, looked at the small cup on the table and said: "On a microscopic level, although atoms are close to each other, the space around the nucleus is huge. For example, this small cup, if it is an atomic nucleus, its The outer electrons may be a hundred steps away, and the space in between is empty. How likely is it that the few neutrons initially released by the reaction will hit the next nucleus?"
Wow, you realize so quickly the problem of trying to maintain a self-sustaining chain reaction? Get to the root of it.
At least in this regard, Zhou Changfeng immediately looked up to her.
This is like being in a shooting range, surrounded by some uniformly arranged balloons, and firing two shots at random. To ensure that at least one balloon is hit (so that the reaction can continue on its own), theoretical calculations are needed to determine how large the shooting range should be. .
The result is...critical mass.
As we all know, Heisenberg miscalculated this data in history and came up with the outrageous data of 54cm radius, which is a full 13,000kg U235, causing the Germans to think this was completely impossible.
Of course, whether he did it intentionally or accidentally is a topic that people are talking about.
Due to the proliferation of information in the Internet era, the data conclusions that people in the past decades spent so much time on have become common knowledge.
It is known that the critical mass of highly abundant spherical U235 is approximately 52 kg, and that of highly abundant spherical Pu239 is approximately 17 kg.
In this regard, being a time traveler has a few inherent advantages. At least Ming scientists can be corrected immediately if they miscalculate the critical mass.
But this is only a small part of a huge calculation project. Real fission weapons require more complex calculations, and those are beyond Zhou Changfeng's power. He can only rely on the wisdom and energy of physicists and mathematicians. .
Seeing Zhu Lingjing talking about this topic with great interest, Zhou Changfeng followed her words and said, "The probability is indeed very slim, so a large ball of uranium is needed to increase the probability to certainty."
Zhu Lingjing thought that Zhou was just an amateur in this regard. She said calmly: "Your understanding of this is a bit shallow. You must know that the direction of movement of neutrons produced by fission is completely random in three-dimensional space."
"Your Highness, I know, so this needs to be calculated using a specific mathematical analysis method."
"Hmm..." Zhu Lingjing said thoughtfully: "This way of thinking seems to have had similar problems before."
She is not a professional in this area. Nuclear physics is just a type of physics classification. If we need to consider mathematical models, it is not a category that she can consider.
"Your Highness, I mainly recommend starting preliminary research as soon as possible."
“But we don’t know yet whether it’s theoretically possible.”
"Then you have to calculate and prove it first. If it works, continue. This discovery in physics is public, and other countries will definitely study it."
Although Zhou Changfeng tried his best to conceal his eagerness, Zhu Lingjing still felt strange. She looked him up and down and said calmly: "Don't be impatient. You can directly submit this idea to the Ministry of War."
Zhou Changfeng, who was quite helpless, replied: "This idea is too advanced. The officials who received the report do not know this knowledge, so they must think it is a fantasy, so it is more effective for you to speak, Your Highness."
"That's right." Zhu Lingjing laughed dumbly and raised her index finger, "Teacher Qibu Gang, when you have free time, go to the university to discuss it with someone, be more authoritative, and I will follow up on this joint effort."
This answer is okay, it’s fun.
The goal has been basically achieved, so there is no need to stay long, not to mention that we haven’t even had dinner yet.
As a result, Zhou Changfeng, who was hungry, immediately resigned.
"He was in a hurry, like a child who found a new toy." Zhu Lingjing couldn't help but muttered when she saw him leaving quickly and disappearing in the blink of an eye.
At first Zhou Changfeng wanted to go home, but suddenly he realized that Xia Xiaoshi was still living in her parents' house and the house was empty now, so he turned back to Jiang Xinzhou.
Although the large force of the 1st Marine Regiment had just loaded up in Haizhou and set off, there were units left behind at the station.
It’s early June in Nanjing and there are already signs of intense heat, but they are not obvious. The next day, Zhou Changfeng arrived at Imperial Gezhi University early in the morning.
The small door made of stone, like stacked blocks, is unique, and the aluminum alloy plaque in Yanti regular script is also very distinctive.
It is not easy for young people to go to college these days. They are either from well-off families or have unique talents. Different from the proliferation of college students in later generations, today's college students are real talents - high professional quality, quick acceptance, and strong practical ability.
The monthly salary of an ordinary college student after graduation can reach 90 yuan, and the monthly salary can basically exceed 100 yuan in just one year. For comparison, the average white-collar employee in Yingtian Mansion in the capital only has more than 60 yuan.
On the vast campus of this polytechnic, almost all of them are male students, and the male to female ratio is probably less than twenty to one.
After several inquiries, Zhou Changfeng found Zhang Shilin, a Ph.D. (Bachelor) from the Department of Chemistry, whom he had met last year.
There are ponds, wooden bridges, and waterside pavilions. Zhang Shilin is sitting alone on a bench holding a fishing rod. His hair and beard are messy, his eyes are wandering, and he is distracted at a glance.
This appearance is really too close to the image of "Frankenstein".
Zhou Changfeng stood behind him for a long time without being noticed. It wasn't until the fishing line started to tremble that his thoughts were interrupted and he hurriedly swung the rod.
Then, he realized that someone was standing behind him.
Zhang Shilin felt that the person in front of him looked familiar, and he tried to think about it, but he just couldn't remember, "Ah, you are..."
"Last year, there was a train from Wuhan to Beijing." Zhou Changfeng reminded helplessly.
"Oh, I remember, Zhou...yes, Zhou Changfeng! Nice to meet you."
"Why are you fishing here?"
"Oh, my research has encountered obstacles. I have been working on it for half a month and there is still no progress. Sir, I have been asked to come out and relax."
Doing academic work is really tiring and laborious, and sooner or later you will be bald.
Zhou Changfeng was silent for a few seconds, and then bluntly stated his purpose.
"Is Chief Zhou also paying attention to this aspect?" Zhang Shilin, who was a little surprised, said while rehanging the bait: "This news has only been out for a few days, and the academic community has not yet reached a conclusion."
"That's not important. I'm looking for a more authoritative scholar. Can you recommend one or two?"
Zhang Shilin nodded and replied without hesitation: "Mr. Xu Shangdanxu from our school is one of the most advanced people in this field in our country."
"Where is he now?"
"It's on campus. It should still be in the laboratory building now."
After thanking him, Zhou Changfeng left quickly and went straight to the laboratory building.
It is not a tall building. On the contrary, it only has three floors, but it is very wide. The black glazed tiles on the roof with curved cornices show a unique luster under the sunlight.
Here, he waited for half an hour.
Xu Shangdan, a nuclear physics tycoon, had a somewhat contradictory impression on Zhou Changfeng. At first glance, he seemed to be an amiable little old man, but at the same time, he felt that he had some inaccessible boundaries.
But Zhou Changfeng soon figured it out. To put it bluntly, this was the admiration imprinted on his subconscious out of awe of knowledge.
"...As soon as the news came out, we were also greatly surprised and quickly tried to replicate the same experiment." Xu Shangdan sighed, stroking his beard: "It's a pity that we were blinded by the appearance and failed to see the essence."
When Ming Dynasty physicists used neutrons to bombard uranium nuclei, they accidentally produced an element with a half-life of 3.5 hours. It is an isotope of element 39, yttrium. This phenomenon is actually enough to prove nuclear fission.
But physicists didn't know the truth. They were fooled by the physical properties of the isotope into thinking that the element, with a half-life of 3.5 hours, was a transuranic element heavier than uranium.
"..." After briefly describing the loss of mass and the energy released during the fission process, Zhou Changfeng asked directly: "May I ask, sir, if you think this is feasible."
Xu Shangdan said in a deep voice: "This requires knowing the reaction cross section of the disintegration and splitting of uranium nuclei induced by neutrons, that is, the probability, and the spatial density, etc. It is very complicated and cannot be concluded... But, if you just ask if there is Hope, I think there is."
Zhou Changfeng breathed a sigh of relief and said with a smile: "This is enough. It will be much faster to focus on research and tackle the key problems than if you spread out now. Mr. Xu, please join me in signing the petition."
"Are you already trying to use it as a weapon?"
"Of course, and we must strive to be the first."
"This...with all due respect, child, the power contained in this is too great." Xu Shangdan said solemnly: "This is not comparable to chemical energy. The speed of light is too fast, let alone its square. Even if only one gram of mass is converted into energy, it is probably equivalent to tens of thousands of tons of ordinary explosives."
Although people today know nothing about the power of fission weapons, as a professional, Xu Shangdan can still intuitively determine how terrifying its power is when he knows the principle of its energy source.
"I know, but the use of weapons is not only to expand territory, but also to protect one's own country. 'Not having' and 'having but not using' are two completely different things. To put it bluntly, what you are worried about is precisely some Western People don’t care, the game between countries is not children’s play.”
"Hey, that's right." Xu Shangdan looked out the sunny window and was silent for a long time, "Besides, even if I don't agree, you will go find someone else."
Zhou Changfeng remained silent and acquiesced.
Next, the two briefly discussed critical mass.
"More than thirty years ago, I can't remember clearly, a British man named Pearson published a newspaper to publicly solve a problem. That is, if a drunk person walks, the direction and size of each step are completely random. Where is the most likely place to find him over time."
"Are you going to use this as a reference to find out the size and weight of uranium required?"
"Maybe, the way of thinking is similar. In the 20th year of Zhichang, senior Li Cheng from Xi'an University summarized this problem and proposed a theorem and proof process called the 'random walk theorem'. The drunkard asked After going forward, backward, left, right, and unit length, the probability of eventually returning to the original position is one, which means that it will eventually return to the origin.”
"Um……"
After a while, Xu Shangdan joked: "If the final calculation yields an impossible figure, will you people be very disappointed?"
Zhou Changfeng was stunned for a moment and didn't know how to answer.
If there is no nuclear deterrence, a large-scale conventional war will occur every few decades, which will not be a good thing for ordinary people, but politicians will not care.
He replied meaningfully: "Soldiers are actually indifferent, but I think the powerful people will be very happy."
(End of chapter)
