2022-11-16

2022-11-12/15

What I wanted to convey in my closing speech
Hideaki Takabe*
Chairman, Program Committee,
The 31st International Toki Conference, Nov. 8-11, 2022.

The international conference sponsored by N I F S (National Institute of Fusion Science:https://itc.nifs.ac.jp/ ) was over in the afternoon of November 11th. The conference was conducted
via ZOOM using the Internet. The program was designed to take into account the local time of theinvited speakers from Europe and the United States. The scope and report of the conference, anexecutive summary, will be written in a separate form. Here I reproduce the 20-minute message I
delivered as the program committee chair at the closing ceremony. This is reproduced for theaudience, especially, for students and junior researchers.

On the first day, Director-General Yoshida said, "We haveto review the research accomplishment as an academicresult. We will clarify the universality of the result anddevelop them in an interdisciplinary manner.” Heexplained his thoughts on the new paradigm by showing
Fig. 1. Don't be satisfied with the sweet taste of the fruitsof your research. Behold the leaves, observe the branches.
Think of the trunk from which academia branches out. Thetrunk is the origin of diverse sciences. Trace the results ofyour research to the trunk. For this purpose,interdisciplinary and international academic development
is necessary. Take in the wisdom of other fields, develop
it, and disseminate it to other fields. Instead of staying put,always ask yourself and your colleagues, ”Where do we Fig. 1
come from? What are we? Where are we going?”.
One of my friends in physics at National Taiwan University is Prof. Hikaru Kawai. He is a particle
theorist in string theory. We had a two-hour discussion about "What is science and academic?" In fact,
every time we go out for dinner, we spend two hours discussing
Fig. 2science-related topics. He is trying to create the universe
mathematically using only the fundamental constants "c, ℏ, G" thatgovern light, quantum mechanics, and gravity (Fig. 2). Particle
theory is mathematical and philosophical. I think his researchmethod is “deductive”. He is challenging to create everything in
the universe. To do so, he investigates the structure of the spacetime of the universe with the theory that seems to be behind theLagrangian of Fig. 3, including the string theory. This is an attempt
to get from the root to the trunk of Fig. 1.
I thought about my case while discussing with Mr. Kawai. “Howdo I, as a plasma physicist, approach branching out? What isacademic in my physics?”. In my case, there are plasmas in front1

2022-11-16of me, though I cannot see them withmy eyes. I see them as aphenomenology and wonder whatkind of physics is woven into them. I
measure them, analyze them, andwrite a paper with my thoughts.
These days, simulation codes arefreely available and anyone can use
them. Today's computers are
extremely
fasterthan
thesupercomputers of the past.
Simulations can be done on PCs aswell. Then, the simulation and theFig. 3
experiment are compared, and if theyagree, the results are happily
published as a science paper. When I read many of the latest papers for writing textbooks, I encountermany such papers. Naturally, I don't read all of them, nor do I cite them. The question is, "What is thephysics of the core?" There is no analysis, or rather no research, on this point. Occasionally, When I
find a paper that talks about the physics of the core, it makes my heart sing.
Plasma science approaches the physics of the core phenomenologically. It becomes a discipline bydescending the branches and reaching the trunk. The methodology of academic research is rather"recursive". It is the search for truth by inductive method, and the study deepens empirically. If youreach the point of branching out, you will meet faces you will never forget. They can be Maxwell,Boltzmann and others (Fig. 4). By borrowing from their wisdom, we begin to see the "core of physics,"
and there we find universal truths. Sometimes it finally reduces to a simple mathematical model
expressing our intuition. Once you find the law of the physical system that govern a complex system, it
becomes a universal achievement.
Scientists who are exploring a different world will also comeback to the trunk and perhaps create a new branch. At such atime, will particle theory, which attempts to imagine everythingfrom the roots up, perhaps predict a "flattened" universe with nostructure. A wonderful creation. But the universe has anextremely hierarchical and complex structure with large scale
structures, galaxy clusters, galaxies, celestial bodies, planets,and the earth.
I do not believe in determinism like "Laplace's devil". I believethat the science of fluctuation, dissipation, instability, transport,turbulence, structure formation, and others having beenchallenged in plasma physics are essential to the connection between the magnificent universe thatbegan with the phase transition of the vacuum and the diverse and profound science of today days.
Fig. 4

When the plasma physics finds science in the trunk where various sciences and technologies that bear
fruit in diverse branches branch out, we may encounter the science of cosmology and particle theory.
There, we confirm that the science that has studied the universe deductively and the science that has

2

2022-11-16

arrived at the trunk inductively are "complementary" to each other.
With mutual respect, the scientific community grows in the future.
The science will deepen and broaden, and universal concepts will
emerge. We have to hand them on to the next generation.
I stopped composing simulation programs in the mid of my 40s.
More than 20 years later, supercomputers are a 'billion times' faster.
This is a revolution. The paradigm of my time would never haveworked. So, I stopped computer programing. I decided to change
Fig. 5generation and leave the younger generation to take over, as shownin Fig. 5. However, through my experience up to that time, I had
５come to see the core of the problem in a big picture. I have passed on that core to the younger generation
and ask them to study it. I tasted a sense of defeat and encountered unexpected results.
At that time, I became a professor and tried to develop new research while I was busy for managing ourresearch institute. It was truly the first attempt at 50 years old. Fortunately, with the help of talented
young people and an international network of collaboration, we were able to achieve results thatexceeded my expectations over a period of 10 years. I even received an award from the APS for ourachievements. Still, I was not satisfied and kept asking myself in the corner of my mind what the"physical core" was. A quiet life in Germany began. In the midst of all this, I had a flash of inspiration.
I came up with a simple mathematical model of a shock wave generated from turbulence. I think I haveseen the core physics that governs the background of experiments and simulations. (To be published inPhys. Plasmas as an invited paper).
With the background ofprogressing
computingpower, I found many
presentations to use theartificial intelligence (AI),such as "machine learning,neural networks, big data,and statistical modeling," toconduct research wisely andto develop science in greater
depth. Plasma physics is alsothe frontier of physics
discovery with AI [1, 2].

Fig. 6５

Artificial intelligence ismodeled on the structure of
the human brain; as shown in Fig. 6, humans have a hierarchical brain that thinks deeply and a brainthat stores broad knowledge, connected vertically and horizontally by neural networks. What thissuggests is interesting. When the human brain digs deep into research, it does not function well when itis the only thing it can see, like an octopus pot. What we see, hear, and learn are accumulated as
information, and ideas are "spontaneously" generated when unrelated things are connected. From there,
they are able to progress to even deeper insights.
Let us compare such a human being to a tree, as shown in Fig. 7, which is a street tree taken in Tokyo.
The tree's trunk grows taller and taller with a goal-oriented approach, saying, "Cut waste, don't gosideways, cut off the branches and leaves”. In some cases, I have seen a slogan“develop energy” written
at the end of the trunk. Some organizations seem to deny academia in universities. I believe that3

2022-11-16

purpose-oriented research doesn’t fit well at universities. I believe that a university should be anorganization that supports academia, basic academic activities. To use a metaphor, university researchis like a "big tree" with leaves growing on large branches like the one in Fig. 8 (the photo shows afamous big tree in Taiwan, visited by young people). The spreading leaves receive a lot of solar energy
and grow further through photosynthesis.

Fig. 8Fig. 7

The title of this conference is "Expanding Academic World Emerging from Fusion Science”. Someyoung participants may not know how to deepen their academic world through international
conferences and discussions. Therefore, I would like to conclude by explaining three things that I havelearned from my experience (or rather, my way of life itself).
(1) Honesty, Openness
Science is an activity in pursuit of truth. Science does not demand lies, deception, or power. We justwant scientists to look at facts, accumulate facts, and find the truth. To do this, they need to be openminded, honest in their explanations, and open to discussion with others. Show your weaknesses,
too. If you are honest, if you say what you think, there will be no contradiction. Distinguishedresearchers see and appreciate such a way of life. This is because they have the moral code. Honesty
is the first step to expand your network.
(2) Fairness
International conferences are not one-way meetings where you just listen to presentations. Speakers
are waiting for questions and comments from the audience, even some new ideas. You should beinspired to find your questions. A meeting without questions is "unfair" and unacceptable. The valueof “gain and loss” is not acceptable. Sports are possible because there are rules. Scientists have rulesof ethics. It is self-evident whether it is ethical or avaricious.
(3) Respect
When talking with children, bend your knees and keep your eyes at the same level. Look them inthe eyes when you talk to them. This is to respect the other person. The same goes for eye-contact.
It is an evidence that you are listening seriously. Meeting people at an international conference is areal pleasure that you cannot experience at a ZOOM conference. A friendly update with an old4

2022-11-16

acquaintance. When you find an interesting talk, you start the conversation with questions anychance after the talk. It's great if you can continue the conversation over a meal or something. Postersession. Respect and question junior scientists from the same perspective as you do. Getting to know
someone means asking them about their scientific stance. It is important to know the differencesfrom your own ideas. Find out what you don't have. This leads to new discoveries. “Humanity”.
Respect humanity in any case in one’s life.

After reading this message, some people will surely scoff and say that it is idealistic and difficult. However, myown argument is that "university people should present an ideal image to society". Now in abroad, I can freely do
the research I want to do, because I am free. I also write textbooks while enjoying traveling and other activities
abroad. I also enjoy meeting new people from different fields. My wife and I are enjoying a fulfilling postretirement life that I could never have imagined if I had stayed in the octopus pot until retirement.

References
1.
2.

Brian K. Speasr et al., Deep learning: A guide for practitioners in the physical sciences, Phys.
Plasmas 25, 080901 (2018).
Peter W. Hatfield et al., The data-driven future of high-energy-density physics, Nature, Vol 593,351 ( 2021).

*Takabe, Hideaki (Aki), ⾼部英明、Professor
8N5, Leung Center for Cosmology and Particle Astrophysics, National Taiwan University (NTU), LeCosPA
Tel: +886-965-210-791 e-mail: takabe@eie.eng.osaka-u.ac.jp
Professor Emeritus, Osaka University (2015-), Professor Helmholtz Institutes Dresden (HZDR) (2015-2020)5