"Do you know the bulldog? They do not seem fierce, but once they bite, they will hold on tightly for a long time. The problem of turbulence has existed for 500 years; once you bite into it, you spend a lifetime of energy holding on,” said Dr. Uriel Frisch during his September visit to PKU.
Yet while Frisch’s metaphor makes the study of turbulence appear daunting and exhausting, the way he speaks belies a far different truth for those with what he calls the “courage to cross the desert,” or the field of turbulence.
Frisch is an internationally renowned turbulence expert and an academician of the French Academy of Science. While nearing 70 years of age, the scientist’s silver hair, gleaming eyes and vibrant personality radiate a much more youthful enthusiasm and energy.
The PKU College of Engineering had the opportunity to interview Frisch and learn more about his motivation to study turbulence and his advice for future Chinese scientists.
Reporter: How did you enter the field of turbulence?
Uriel Frisch: In the sciences, there are always role-models,like my mentor, Robert Kraichnan. Forty-fiveyears ago, when I was probably 23 or 24, I entered the field of turbulence because of the influenceof Robert Kraichnan. He was Albert Einstein's last assistant,and in field of turbulencehe was an incredible "bulldog".
He passed away last year. This year’s "International Turbulence Conference" hosted at PKU by Professor Chen Shiyi and Professor She Zhensu was in honor of Robert Kraichnan.
Reporter: In such a difficult field, what qualities make you stand out?
Uriel Frisch: Turbulence is one of the most difficult disciplines of physics and mathematics. Those who want to solve it quickly are soon discouraged and usually leave the field. In thestudy of turbulence, you have to spend not one life but several lives. Perhaps five hundred years later, the problemwill still exist, but there will still be peoplemotivated to understand it. Therefore, we need to be patient.
I am not a patient person by nature; in the subway I don’t want to wait for more than 10 seconds. But for turbulence, I can wait for twenty, thirty and even fifty years. The personal decision to work in a subject with slow progress and no end in sightis not a logical decision, but one made by your heart. Some people spend their entire lives praying and studying religion, and they are called “monks”. Decidingto be a monk is not an easy decision because you have to give up a normal life. Inscience, working in turbulence is a little bit like becoming a monk. You have to seek with your entire heart. It can be said, in the field of turbulence, you need the courage to cross the desert.
Reporter: What makes one motivated to study turbulence?
Uriel Frisch: Problems that one can solve in one weekend don’t interest me.If a problem is challenging, Ilike to study it. Studying turbulence, one does not expect to make major discoveries and lots of money. But to work on turbulence you’re probablynot be motivated by money. Turbulence is a subject which does not guarantee any solutionsin your Ph.D. Actually, it is almost guaranteed that you will not solve any problems in your Ph.D. The turbulence question relates to the origin of the universe and origin of life. It’s a very broadquestion and making progress is a very, very slow process. So people working in this area must have areal interest.
Reporter: How do you look at the importance of fundamentalresearch?
Uriel Frisch: The infrastructure of Beijing has made significantprogress. Infrastructure does not directly produce, but it is essential to urban development. Fundamental research, compared to the applied research, is a little bit like infrastructure. In the field of applied science, you can make a car for instance. But we need to understand things in a deeper level. Fundamental research provides understanding, which allows you to go about things much more rationally and at a much greater depth.
Nineyears ago, to celebrate the year 2000, the French government held 365 seminars to discuss challenging issues. Of course, the subjects nearly covered all scientific areas. What surprised me was that the subject that got the most coverage and that most people talked aboutwas turbulence. In seminars debating the automotive, finance, marketing, and medical sectors, turbulence was also discussed. Basic science is the foundation for solving many practical problems.
"Puttingthe ancient Chinese tradition into science"
Reporter: As China continues to develop,scientific research is very important. What is your view on this?
Uriel Frisch: China is in the rehabilitation process. We should not just be thinking about tomorrow, but much further.China has made very good efforts in science. But using scientific achievement to be first or to win more Nobel Prizes is only one dimension. There is another dimension:to understand things at a deeper level, to understand them rationally. To spend moneyon education and science is good, but this may not be enough. Modern Chinaneeds to combine its ancient traditionswith science to understand complicated problems. This will make for asolid foundation for many centuries.
Reporter: Can you explain what you mean by "combine ancient traditionswith science"?
Uriel Frisch: Chinahas 1.3 billion people, and a lot of discoveries will be made with such a large human resource; however,if the country does not have enough tradition, or if traditions that once existed are shelved for whatever reason, it will also be a problem. Therefore, our traditions need to be rebuilt. In China, we have a great philosophical tradition. We need to study your own history of science. Combine thephilosophical tradition into the scientific tradition. We need to find a link between tradition and reality, which will be very helpful to the development of science. India's experience is very similar, and worth learning from.
Reporter: Do you have any advice for youth who want to work on turbulence in China?
Uriel Frisch: My suggestion is be careful not to separate mathematics, physics, engineering and other disciplines too early. You know in collegeyou have to major in something. Things we don’t major in we tend to stop learning about.In the study of the theory of turbulence, we need a lot of mathematics. So if there is not enough math education there is a problem. China now has some very good mathematicians. Mathematics is akind of gateway to a lot of other areas. If the training inmathematics is too narrow, focusing exclusively on puremathematics, students may never have the ability to interact with other fields. In France it’s not the case, and in Russia it’s also not the case. But in China we can see thisproblem.
This is also one of my main concerns this visit to China. So in the next few days, I intend to spend some time with the students here. Now we are talking not about the problem to be solved in the next 500 years, but about the questions to be solved in the near future. Besides, I also want to recommend this website to students: (http://www.scholarpedia.org/article/Turbulence).This is an elementary introduction to turbulence, which I just wrote with Prof. Roberto Benzi (Rome). It might help those who want to know more about turbulence.
Reporter: How do you prospect China's turbulence research?
Uriel Frisch: China has excellent people in this field, but now, as a whole, China is not the leader of this field. Even though the problem may not be solved completely in 500 years, people can still make breakthroughs continuously. I think perhaps in 10-15 years, Chinacould become one of the leaders in this area. In the field of turbulence, we do not need thousands of people; we need some geniuses thatare willing to put their life energy intothis area and that are not motivated by only money.Turbulence is an international subject. So students studying abroad and international cooperation in the framework are very important.
Reporter: Forty-five years focusing on turbulence could not have been easy!
Uriel Frisch: Compared to the 13.7 billion years of the universe’s history, and compared to a few million years of human history, this is short.
Uriel Frisch is an internationally renowned expert in the field of turbulence. His monograph "Turbulence: The legacy of AN Kolmogorov" (1995, Cambridge University Press) has been widely cited in this academic field.