Interview | Professor, Institute of Physics, Chinese Academy of Sciences · Cao Zexian
The following is a summary of the interview
<h1 class="pgc-h-arrow-right" data-track="7" > era abandoned you, not even a greeting</h1>
△ Cao Zexian
Cao Zexian is a researcher at the Institute of Physics, Chinese Academy of Sciences. He is a man who loves science, a physicist, an Internet celebrity professor, a teacher, and a writer.
Cao Zexian: You will encounter all kinds of machines at work, cameras, OB trucks, cameras... How does the various instruments feel to you?
Tagawa: I think they are all tools, which actually makes me feel afraid, and at the same time feel that they are a manifestation of human intelligence, but I don't know more about the knowledge behind them.
Cao Zexian: Let me tell you a feeling that all machines are transparent to you. As long as you know what this instrument is for, you can construct it in your mind, what principle it is, what components it has, how it works... Do you know how cool that feels? I was learning experimental physics and got a hint from someone else's book that you should have the ability to make these instruments transparent in front of you.
Cao Zexian: Too many people mistakenly think that with an instrument, they can work according to the instructions. No, you still have to master this knowledge. I was one of the first Sino-German doctors of experimental physics, and now the students in the lab are doing the work that I did when I was younger. Even these instruments, from the structure to what components they have and what the principles are, they draw their own drawings, and all the instruments have to be as transparent as if they were transparent.
Let's take the example of a camera, do you know how many people were envious of taking a color photo in the eighties and nineties?
Tagawa: Yes, before each trip, you must buy film before taking pictures.
Cao Zexian: Yes, but one of the particularly bad things about it is that when the foreign image is lighted on the film, we need to manually roll the film away, so you can't take a few photos a minute. But do you know how many photos a second the camera we use in the physics lab today can take?
Tagawa: 10 photos? 100 sheets?
Cao Zexian: Relying on CCD components, you can take tens of millions of photos in a second, and hand-rolled film can never be so fast. So when this technology was developed, film was quickly eliminated. So sometimes "the times abandon you and don't even say hello."
We now have new superstructured materials, from the perspective of photographic technology, we do not need to focus, we can shoot first, and then extract the required information later. Second, we have achieved the goal of shooting objects behind obstacles, even if we use a wall to block it.
△ Film camera
Cao Zexian: In the early days, there were many instruments in our laboratory that needed to be imported, and now our country's processing capacity is already very strong. But unfortunately, we still have to rely on imports for a considerable number of precision machinery manufacturing, because we can only see the product now, we can't see the invisible, invisible technology and science under it, so it is difficult to keep up.
△State Key Laboratory of Surface Physics, Institute of Physics, Chinese Academy of Sciences
Cao Zexian: People who understand a little bit of technology and those who don't understand technology at all see things that are not the same. With basic physics knowledge, you'll find that you can see more information even when you watch the news.
Tagawa: I remember you saying that today's young people know a little about quantum mechanics and relativity, so they can be regarded as a qualified youth.
Cao Zexian: Yes, because our society today is progressing so fast, you really don't know what black technology will appear tomorrow. The "black technology" I am talking about here does not refer to the public's feeling of science and technology, but even those of us who are active in the front line of scientific research feel that technology is advancing too fast. So if you don't have enough scientific knowledge, it will become difficult for you to understand what is happening in your life.
<h1 class="pgc-h-arrow-right" data-track="24" > the magic of abstract thinking! </h1>
Cao Zexian: When China first established physics, the conditions were very poor, and it was very difficult to have an electromagnet. Past efforts have contributed in no way to China's modernization today. At present, almost all the strong magnets in the world are supplied by China, and this technology comes from our research institute.
Cao Zexian: The first principle of physics is to understand the world, to understand the truth of this world, and then to apply. Physics brings many applications, but you can't see everything and think about applying them.
Tagawa: You said that we have a bad habit in science education, one is not to talk about scientific content, the second is not to talk about scientific research methods, and the third is not to talk about the real scientific spirit.
Cao Zexian: Because these people who do science education do not know what the true spirit of science is.
Tagawa: What do you think is the true spirit of science?
Cao Zexian: First, the knowledge of learning itself is about nature, it is not subject to my will, and the most basic content is to respect the facts, but many people cannot do this. Another point is that the scientific spirit has a habit of moving toward abstraction, which may also be something that our culture lacks.
Tagawa: As an ordinary person, if I didn't move toward abstract thinking habits, would it have any impact?
Cao Zexian: If you know the world figuratively, then your understanding of the world is fragmented in many places. When you have the ability to bring figuration into the body of knowledge and become an abstract form, you may understand a lot of things in a simple sentence.
For example, the heat engine is a typical thing of the first industrial revolution, when people want to make the heat engine more efficient, the figurative thinking people began to do a variety of technical research attempts, but the Frenchman Sadie Carnot did an abstract thinking, the efficiency of the heat engine can not be improved, is it because the efficiency is actually limited? What determines its ceiling? So Kano understood waste from the perspective of complementarity of work, and finally figured it out. Because the working principle of the heat engine is from one equilibrium state to another equilibrium constant state, if the waste is removed, the rest is useful. So Kano changed from thinking about how to do the best part of the useful to thinking about how to minimize waste, and drew a carnot circular work map.
△ Kano loop diagram
Cao Zexian: The most important principle in thermodynamics is that "any heat transfer that is not for the purpose of work is called waste." "When I was studying thermodynamics, I didn't understand how I could take such an impossible thing as a principle. But this impossible, abstract content is the highest principle.
Do you know how much this irregular quad painted by Kano affected humans? Because the way the heat engine works is to absorb heat at high temperatures and then put them into low temperatures to work, this process is one-way. While Carnot painted the non-existent circular diagram described, this process is reversible. People were inspired to think that if the heat was transferred from the low temperature place to the high temperature place by working, wouldn't the low temperature place become colder? People suddenly know how to refrigerate, there are air conditioners, refrigerators, today someone can run a factory and a university in such a hot place in Shenzhen, which is the power of abstract thinking.
△ Sadie Carnot
“
There is a saying that for every additional formula, the readership of a book is halved. According to this statement, the number of readers of this book will be less than 1. Mathematical formulas may scare the reader away because they appear in a blunt, intimidating way, as someone translates a well-worn German philosophy into obscure texts, and the problem lies in the unethicalness of the author or translator, not because of the unspontaneity of mathematics or philosophy.
”
—— "A Thought Extraordinary" Cao Zexian
Cao Zexian: The formula is not just to write an equal sign in the middle of two letters, it is associated with a large physical image, and the formula is a description of the world.
Tagawa: That's why it's so painful for everyone to study physics and mathematics, because we're always memorizing these formulas by rote.
Cao Zexian: From the perspective of formulas, there are fewer things you need to memorize when you have formulas. For example, write with a pen:
1，1，2，3，5，8，13，21，34，55，89，144。
Cao Zexian: Is it chaotic when you talk about it? In fact, this string of numbers has a formula, that is, any number is the sum of the first two numbers, that is: F(n+2) = Fn+F(n+1), is it suddenly felt that nothing needs to be remembered.
The formula is the hook on the net pocket, as long as the hook is still in your hand, everything in the net pocket is yours. But if you want to count what's in your pocket and hold everything in your hand, your hand won't be enough.
Tagawa: How did you translate these profound things to the public in a very down-to-earth manner?
Cao Zexian: Learning is also produced from nature, if there is a jump in the middle of your learning, or someone tells you the result halfway through, but you don't pursue its source, then you can't restore these contents to the level of earth qi, and you can't talk about it in a down-to-earth manner. When teaching thermodynamics, I read all the english, French, and German classic articles related to thermodynamics, page by page, and I must build up all the chains of thermodynamics. After completing the details, it is found that thermodynamics is actually particularly easy to understand.
<h1 class="pgc-h-arrow-right" data-track="50" > young people to go to good schools</h1>
△ Cao Zexian Childhood photos
Cao Zexian grew up in rural Anhui Province, where his family was poor.
Cao Zexian: When I was a child, my family was surrounded by walls, and almost only sweet potatoes were eaten in winter.
I grew up in the mud, not only was the road to school full of mud on a rainy day, but I read that the desk was still muddy when I read in the third year of junior high school. At that time, there were no books, no teachers, only ignorant eyes that could not be dissolved. The road from muddy feet to distant clouds is a real road, more real than real because of abstraction.
—— "At the Foot of the Clouds" Cao Zexian
Tagawa: You say that you are a person who is particularly good at self-study, what is your motivation to learn?
Cao Zexian: I can't think of what the motivation is, if I don't go to school, I have to be driven to work in the field, cut pigs and grass, and herd sheep, maybe this is the reason why I want to go to school.
Cao Zexian later said that the poverty of knowledge limits our imagination. In 1982, at the age of 16, Cao Zexian entered the Department of Physics of the University of Science and Technology of China.
Cao Zexian: When I was in college, I would most likely put my mind on where my next meal would be, and there was a big patch on my chest in the clothes I wore in winter... Our inferiority complex makes us never look up at girls. The book is poorly read, especially natural. I've been working for a long time, and I'm still living to be able to feed and survive.
△ Cao Zexian In his youth
In 1997, he finally received his Ph.D. in physics from the University of Kaiserslautern in Germany. Until his ph.D., Cao Zexian still used confusion and ignorance to describe the physical world in his eyes.
Cao Zexian: We must admit that in the field of mathematics and physics, there is a good chance that all of us are economically well-off. People don't have much time in their lives, and if they want to achieve something, they have to be able to concentrate on doing it in the direction they choose. If you still have to think about today's meal, think about which profession is good to find a job, which subject can apply for the fund, the achievement will naturally not be too high. This is why I later stressed that we must not let the talents worth cultivating be bothered by the problem of eating. At the same time, it also reminds everyone that we must put our ambitions a little higher, your realm is high, and your future achievements must also be high, which is actually very important.
△ Cao Zexian Germany
Cao Zexian: I have always encouraged young people to go to good schools, what are good schools? It means who you can meet. I remember very clearly that on April 1, 1997, when I left work, I saw the obituary of Professor Hunt's death next to the school elevator. Professor Hunt is the name that appears in my university textbook on atomic physics. I thought he was a great foreign scientist like Newton and Galileo, and he summed up what rules he had, and I memorized whatever was written in the book anyway, and as soon as the passing exam book was thrown away, it was over. As a result, I actually saw his obituary on the elevator that day, and I learned that he was alive and lived not far from my school. For the first time, I felt deeply that when great people are close to you, a feeling arises in your heart, and maybe I can create.
Tagawa: I felt that I was called inside and saw a possibility.
Cao Zexian: Yes, after becoming a professor, I also got to know some scientists, even some Nobel Prize-level scientists. Old Mr. Yang Zhenning is a very modest person, and he will call me Zexian Xuedi. This simple action may not mean anything to him, but it has already affected me for me, or in a sense, lit a fire in your heart. So I said to send all kinds of successful people to remote villages, don't do anything, just let the children see them.
Choreographer: Wang Jie, Sun Wanning
Edits: 612