"Can I use the blackboard?"
"The calculation process is very complicated," Professor Zhang threw the chalk in his hand on the lecture table, put his hands behind his back, and said with a smile, "Whoever can complete the rest of the part will get my usual grades for this course." Give it all to him, and you won’t have to take this class anymore.”
"...According to public data, the STAR-2 demonstration reactor - or the current Pangu reactor, has a peak internal core temperature of 130 million degrees Celsius, which is nearly 9 times the temperature at the center of the sun!"
At this time, Lu Zhou noticed that the teacher's name and phone number were written on the open title page of the quantum mechanics textbook under his arm.
Swish, swish, swish!
The classroom fell silent.
who I am
After stopping the chalk in his hand, Professor Zhang turned around, looked at the confused students, and raised the corners of his mouth.
"Quantum mechanics is a very profound subject. If you really understand it deeply, its existence will even subvert your understanding of the microscopic world, physics, and even classical philosophy. Although I know my voice may be very good It helps you sleep, but I don’t recommend you start sleeping from the first class... "
Zhang Zhongqing
"We all know that the STAR-2 demonstration reactor in Haizhou was successfully ignited under the command of Professor Lu from our school some time ago. Our country's controllable fusion power generation technology has also been at the forefront of the world and has become a It is the only country to build a commercial reactor."
Inspiration doesn't just come to you, you have to find it yourself.
When Lu Zhou happened to hear this complaint, he raised his eyebrows with interest and was about to ask him what he had in mind. But before Lu Zhou could speak, he continued.
Zhang Zhongqing: “…???”
Lu Zhou agreed with what Fermi once said. Thinking about why some obvious problems are obvious can help deepen the understanding of those profound and difficult problems.
How come you can talk about quantum mechanics and relate it to him
"Isn't this nonsense?"
"I think... you can understand?" The guy glanced at Lu Zhou in confusion. Maybe he was awake and didn't realize who was sitting next to him.
"I know!" After receiving the professor's signal, the female academic in the front row wearing glasses stood up and replied quickly, "Because the atomic nucleus is positively charged, there is a Coulomb repulsion between the nuclei. .Only when the two nuclei are close enough, can the strong interaction force overcome the Coulomb repulsion and bring the two nuclei together. On a macroscopic level, only by increasing the heat in the system and accelerating the thermal motion of the molecules in the system can Make the nuclei of atoms collide together with enough kinetic energy to cause a fusion reaction."
"This is the explanation in the high school physics textbook, and there is no difference between saying it and not saying it," Professor Zhang smiled, motioned the student who stood up to answer to sit down, and continued, "You are college students now. In addition to knowing In addition to the 'what', we should also understand the 'why'."
Lu Zhou smiled and said, "If you want, I'll teach you."
It's normal not to understand.
Hearing these words, Lu Zhou, who was sitting in the back row listening to the class, suddenly felt embarrassed.
Less than half of the people sitting in the classroom could understand what Professor Zhang was talking about.
However, it may be a flaw that his voice is not loud.
At least the buddy sitting next to Lu Zhou has no plans to wake up yet.
It was deathly quiet in the lecture theater.
"General materials cannot withstand such a temperature. Therefore, our country's STAR-2 demonstration reactor uses magnetic confinement to confine the deuterium and tritium mixture of ionized state I participating in the reaction in a closed magnetic cage. .”
Kind laughter rang out in the classroom, and Lu Zhou, who was sitting in the back row, couldn't help but smile.
For him alone, there is no problem in memorizing the conclusion, but if he is asked to calculate it on the spot, he may not be able to calculate it before the end of get out of class.
Actually it's not just him.
"Suppose scattering occurs between two resolvable fermions (p+k→p'+k'), then under the Bourne approximation, the following relationship can be obtained between the scattering cross section and the interaction... "
"Want to know?"
After glancing at those who had woken up and those who had not yet woken up, the middle-aged professor shrugged humorously and continued to lecture without caring.
"That's a good answer." He wrote down a score on the roster. The middle-aged professor cleared his throat and continued with a smile, "Then the question is, have you ever thought about why the strong interaction only occurs at extremes? Can it happen at a short distance?"
Especially when it comes to calculations, it is impossible without a certain mathematical foundation.
The buddy sitting next to Lu Zhou curled his lips and muttered something under his breath.
After glancing at the classroom where no one raised their hands, Professor Zhang, who was standing on the podium, could only add, "This question has usual results."
Looking at the exclamations of students in the classroom, Professor Zhang, who was standing on the stage, was secretly happy. Knowing that he had successfully grabbed the attention of the students, he immediately struck while the iron was hot.
"... If this can be done at normal temperature, then not everything can undergo nuclear fusion."
With that said, Professor Zhang turned to face the blackboard, writing and preaching at the same time.
Even the graduate students who came to take classes looked confused.
"Quantum field theory tells us that the interaction between particles is not an interaction at a distance, but is carried out through some kind of boson as a medium. For example, the electromagnetic interaction exchanges photons, the strong interaction exchanges gluons or mesons, and the weak interaction exchanges gluons or mesons. The interaction exchanges W and Z bosons... Some people may ask, what does this have to do with the scope of the force we are talking about?"
All the students looked at each other.
"Because... it's a short-range force?"
Although he was only distracted for two seconds, he felt as if he had missed a whole semester of classes.
Looking up at the calculations on the blackboard, the buddy sitting next to Lu Zhou had a confused expression on his face, wondering if he had fallen asleep in class and traveled through time.
Gently pushing the back door open, he glanced at the middle-aged professor who was writing on the blackboard with his back to the classroom. Lu Zhou did not disturb him or the other students attending the lecture, nor even disturbed the sleeping buddy next to the door. The platoon found an inconspicuous seat and sat down very low-key.
Whether this sentence is applied in physics or mathematics, there are precedents to follow.
For example, when he was studying Goldbach's conjecture, a number theory class taught by Professor Fefferman gave him great inspiration. And this is not because he taught so profound things in class, on the contrary, what he taught at that time was just some very easy-to-understand things...
[〈p'|iT|p〉=-iV(q)(2π)δ(Ep'-Ep), (q=p'-p)]
After glancing at the confused buddy next to him, Lu Zhou smiled and asked softly.
The class seemed to have just started not long ago.
Quantum mechanics itself is a difficult topic in physics.
where am I
Lu Zhou: "..."
After finishing writing on the blackboard, the middle-aged professor standing on the podium cleared his throat and spoke.
"Can any of my classmates stand up and talk?"
It seems that this professor is a young scholar with some teaching skills. At least he does not read the preface from the PPT as soon as he opens the textbook.
When they heard the usual results, more than half of the people in the classroom immediately raised their hands.
This isn't plasma physics.
However, the professor on the stage gave a very interesting lecture. The students in the lecture theater were obviously very interested in this topic. Even the guy who was sleeping soundly next to Lu Zhou raised his head sleepily. Come on, look at the podium with a confused look on your face.
"Hold the grass? Aren't you talking about nuclear fusion... What's the date today?"
never heard of that…
[…]
When he was at Princeton, if he encountered a difficult problem that he couldn't understand, he would take the time to give a few classes to undergraduates, or occasionally go to other professors' classes to find inspiration.
"Then here comes the question. I would like to ask the students, why does controlled fusion require such a high temperature to carry out the reaction? Or in other words, why can't the fusion reaction be carried out at room temperature?"
Professor Zhang smiled and shook his head. Just when he was about to assign this question as a thinking question, a voice came from the back row of the classroom.