On Kamefuchi's Essay about Heisenberg and Yukawa (6)

References [25–28] of this article.

4 Different methods of theoretical physics research

Kamefuchi divides the methods of theoretical physics research into the "ascending type" and the "descending type" to explain why Heisenberg's and Yukawa's later studies were unfinished. In the "ascending type," the researcher "builds up the theory from the basic points." In the "descending type," he or she "sets a hypothetical principle at a high level far beyond the existing theoretical system and descends from there to try to deduce all the laws of physics. Kamefuchi adds, "In the latter method, one has to rely on intuition or analogy. Neither of these has objectivity or inevitability. So, mostly one goes astray." He then infers: Both Heisenberg and Yukawa achieved results by the former method in the first half of their career. However, they turned to the latter type in the second half, failing to complete the research.

Yoichiro Nambu also described a similar classification of research methods [25, 26]. Kamefuchi thinks that the research method can change between the first and the second half for one researcher. On the other hand, Nambu names them by the proper name of famous physicists as if a researcher uses a single method throughout his or her life. However, we should understand each of them to be the one related to the representative, successful research done by the physicist used for the naming. Nambu calls his categories "Yukawa mode" and "Dirac mode" in [25]. As an explanation, I will introduce a concise one in the book by Michio Kaku and Jennifer Thompson [27].

The Yukawa mode is deeply rooted in experimental data. Yukawa was led to his seminal idea of the meson as the carrier of the nuclear force by closely analyzing the data available to him. The Dirac mode, however, is the wild, speculative leap in mathematical logic that led to astonishing discoveries, such as Dirac's theory of antimatter or his theory of the monopole [...]. Einstein's theory of general relativity would fit into the Dirac mode. ([27] p. 85)

Later, Nambu modified this and divided his classification into three types. [26] The explanation for each is as follows.

• Einstein mode (top-down): To create a theory by assuming that "nature should follow this principle." Example: Einstein's theory of gravity (general theory of relativity), made under the assumption that "in general, space may be curved."
• Yukawa mode (bottom-up): To start from the working assumption that "behind the new phenomenon, there is some new field or particle, apart from deep reasons." Examples: Yukawa's meson theory and Pauli's neutrino hypothesis.
• Dirac mode (from heaven): To assume that a mathematically beautiful theory should be true. Examples: Dirac's monopole theory, supersymmetry theory, and string theory, currently being explored.

Einstein's general theory of relativity, which was an example of the Dirac type at the stage of literature [25], was promoted to the independent one. As a result, the Einstein type (top-down) and the Yukawa type (bottom-up) have become equivalent to Kamefuchi's "descending type" and "ascending type," respectively. Nambu states about the examples of Dirac-type as follows. 'The existence of the monopole is now the natural consequence of the quantum field theory, but we still need to confirm it by observation. Studies of supersymmetry and string theories are currently in full swing, so we can say that it is "the heyday of Dirac mode" nowadays.' However, the success or failure of these theories is still unclear, and it is interesting to keep an eye on what a future comes for the high energy physics theory.

By the way, I wonder if Einstein's general theory of relativity is entirely top-down. This is because it is known that there was a thought experiment at the starting point for him to come up with this theory as quoted by Holton ([28], p. 78): "For him, at least in the vicinity, there is no gravitational field during the fall, for example, given an observer who falls freely from the roof." Kamefuchi does not state that Einstein's mode of thinking had been top-down since the time of the general theory of relativity. Instead, he writes that Einstein also turned to the use of the top-down method in the 30 years of his later life for trying unsuccessfully to unify the gravitational and electromagnetic fields.

Here I would like to add the story in Kaku and Thompson's book [27] that Nambu's friends named a type that combines the first two classifications by Nambu "Nambu Mode." They made this naming in commemoration of Nambu's 65th birthday (1985). I quote the related part below.

[...] This mode combines the best features of both modes of thinking and tries carefully to interprete the experimental data by proposing imaginative, brilliant, and even wild mathematics. The superstring theory owes much of its origin to the Nambu mode of thinking.
Perhaps some of Nambu's style can be traced to the clash of Eastern and Western influences represented by his grandfather and father. [...] ([27] p. 85)

Acknowledgement

I heartily thank Naoki Toyota, Professor Emeritus, Tohoku University, for his telling me that there is a story in Ref. [10] that Bohr criticized Pauli's lecture as well as for his other useful suggestions provided by email exchanges on the topic of this article.

References

25. Y. Nambu, "Direction of particle physics," in Proc. Kyoto Int. Symp.: The Jubilee of the Meson Theory, Kyoto, Aug. 15–17, 1985, edited by M. Bando, R. Kawabe, and N. Nakanishi; Prog. Theor. Phys. Suppl. No. 85, 104 (1985).
26. Y. Nambu, One Hundred Years of Elementary Particle Physics (International Institute for Advanced Studies, Kizugawa, Kyoto Prefect., 2000) in Japanese.
27. M. Kaku and J. Thompson, Beyond Einstein: The Cosmic Quest for the Theory of the Universe (Oxford University Press, Oxford, N. Y., 1997; first edition, Bantam, 1987).
28. G. Holton, "What, precisely, is "thinking"? ...Einstein's answer," in Einstein, History, and Other Passions (AIP Press, Woodbury, 1995) p. 74. [See also "On trying to understand scientific genius," in Thematic Origins of Scientific Thought: Kepler to Einstein, Revised edition (Harvard University Press, Cambridge, Mass., 1988) p. 371.]

(End)
Search word: Kamefuchi-2020

From Fujioka's Fluid Drop Model of Atoms to Einstein–Arakatsu Relationship

I have made a lot of exchanges with Bill Streifer (a researcher and freelance journalist on Intelligence, nuclear work and North Korea) at the Quora site from July 9 to 13, 2015. Most part of our exchanges is reproduced here by Bill's permission.

---

Bill: Was Prof. Yoshio Fujioka's "fluid drop" model of the atom known as ekiteki?
And if so, why?

Tatsuo: I haven't learned about Yoshio Fujioka's "fluid drop" model of the atom but guess that if he proposed such a model, it should have been called "ekiteki" model. "Ekiteki" is the Japanese word for "fluid drop" (eki=fluid, teki=drop).

Bill: Prof. Ayao Kuwaki was a Japanese scientist and a friend of Albert Einstein. When did he die, exactly?

Tatsuo: According to the information page of him in "Wikipedia" (Japanese edition), Ayao Kuwaki was born on September 9, 1878, and died on May 16, 1945.

Bill: At the end of the war, an American airman met a man who claimed to be a student of Einstein in Germany. When I learned of Kuwaki, I suspected it might have been him. But now I see that's not possible since Kuwaki died in May 1945 and the "meeting" took place in September 1945.

Tatsuo: Sure, the student should not have been Kuwaki.

Bill: He might not have been a graduate student of Einstein, but he may have attended Einstein's lectures in Germany. Can you guess who he might have been? [And he lived in northern Korea in 1945!] An Einstein scholar is not willing to guess.

Tatsuo: I have no idea about that person.

Bill: If you provide a number of possibilities, I'll check each one. Did Hideki Yukawa study under Einstein?

Tatsuo: No, Yukawa didn't study under Einstein, but they met each other for the first time in Princeton on the former's return trip from Europe in 1939.

Bill: Einstein wasn't in Germany very long. I wonder if any Japanese or Korean scientists studied under Einstein when he taught there, or even attended his lectures.

Tatsuo: The Japanese physicist Jun (Atsushi) Ishiwara seems to have studied under Einstein in Germany (石原純 - Wikipedia). Ishiwara worked as an interpreter when Einstein visited Japan in 1922.

Bill: Thanks. Did Einstein have other Japanese students or followers in Germany? Kuwaki appears to be a little too old. I'm looking for a Japanese scientist who lived until 1946 at least.

Tatsuo: I don't think that Einstein had other Japanese students or followers in Germany.

Bill: I know of another.

Tatsuo: You Know? Who is he?

Bill: Dr. Bunsaku Arakatsu.

Tatsuo: Oh, Bunsaku Arakatsu was a teacher of my teacher and an experimental physicist. So, I didn't think he had studied under Einstein. Wikipedia page for him (Japanese edition) writes that he studied in Europe (Berlin, Zurich and Cambridge) for two years from 1926. It must have been a short time during this period that he studied under Einstein. By the way, his look is similar to Einstein's in some photos of him.

Bill: Can you find any photos of Einstein and Arakatsu together? If you can, please send them to photografr7@yahoo.com.
Is your teacher still alive? If so, could you ask him if Arakatsu or Yukawa visited Konan (Hungnam), Korea during the war? By the way, Konan and Hungnam are the same place, Konan is the Japanese pronunciation and Hungnam the Korean pronunciation.
You might also be interested in knowing that my article about an Austrian chemist who worked at Konan for more than two years (1935-1937 & 1940), will appear in a book being published by the University of Vienna Korean Dept. later this summer. The name of my article is A Letter from Korea.

Tatsuo: I don't have any photo of Arakatsu.
My teacher Kiichi Kimura at Physics Department, Kyoto University died in 1992. I haven't heard of Arakatsu's or Yukawa's visit to Hungnam (Konan), Korea. However, Arakatsu was associated with another Konan. Namely, he was the president of Konan University in Kobe, Japan, after his retirement from Kyoto University. Konan of Korea and Konan of the university in Kobe are different from each other when written in Chinese characters. The former Konan is written as 興南, and the latter, 甲南.
I have not so much interest in the history of science in Korea. However, if you write about some history of physics in Japan, I would like to read it very much.

Bill: I am familiar with Kimura. I am also aware that Konan, Japan is different than Konan, Korea.

Tatsuo: May I quote our exchanges made here these days in one of my blog sites written in English? Some friends of mine might be much interested in our exchanges.

Bill: Yes, that would be fantastic. And if anyone has any questions or comments, they can contact me directly at bill.streifer@gmail.com.

Tatsuo: Thanks a lot for your permission.

Bill: Stay in touch.

—A few days later we had additional exchange as given below.—

Bill: You can add this: According to page 15 of the book Uranium Matters: Central European Uranium in International Politics, 1900–1960 by Zbyněk A. B. Zeman and Rainer Karlsch, the Japanese physicist, Dr. Bunsaku Arakatsu "studied at Berlin University ... under Einstein, becoming a member of Einstein's close circle of friends."

Bill: I returned to the original document, and I am now convinced that the American airman met a Korean scientist, not a Japanese scientist in Korea in September 1945. But it's still interesting that Arakatsu was a close friend of Einstein, so all of this work wasn't for nothing.

Tatsuo: I've been on a trip to my hometown since Tuesday and am writing a belated reply. Thanks a lot for your additional information. We surely have gotten a good fruit.

(Last modified on July 29, 2015)

Comparison between Feynman and Einstein by Peter Galison

A collection of the letter's of the Nobel-prize winning physicist Richard Feynman, edited by his daughter, Michelle Feynman, was recently published [1]. Reviewing this book, Peter Galison of the Department of Physics, Harvard University, compares Feynman and Albert Einstein [2].

Galison starts his review by the sentence, "Richard Feynman was a physicist's physicist," and writes about Feynman's contributions in fundamental physics and beyond as well as his public intervention in the analysis of the 1986 Challenger space shuttle disaster. Then, he refers to Feynman's fame within and outside the physics community, adding, "Young physicists regularly tack a poster of Feynman above their desks. If there are posters of other Nobel prizewinners on sale, I haven't seen them. [My note: Here is a line break] Except, of course, for Albert Einstein." — Yes, I saw a photo of Feynman even on the desk of a young physicist at Kharkov University in Ukraine, where another famous physicist Lev Landau had worked. —

In a next paragraph, Galison describes about Einstein's iconic status extending far beyond the physics world, and states, "And yet, since the early 1960s, generations of science students held Feynman, not Einstein, as their model and guiding star." — Similarly to other physics students and physicists in earlier days, I had held Einstein as a model and guiding star until I read Feynman's book "Surely You're Joking, Mr. Feynman!" [3] in 1985. I was a latecomer to the community of Feynman fans, though I read the three volumes of The Feynman Lectures on Physics [4] earlier than that and liked the volumes very much. —

Galison compares Feynman and Einstein, writing as follows (numbers are attached by me): (1) Einstein never lost his fascination for philosophy; Feynman found philosophers nothing but a burden. (2) Einstein came to believe that physical reality lay deep in mathematical physics; Feynman never gave up hoping for a physics driven, at bottom, by an almost tactile intuition. (3) Much of Einstein's life found him cast and self-cast as an oracle; Feynman preferred the persona of a fast-draw street-smart kid.

Galison concludes: "Yet beyond these striking differences, both Einstein and Feynman found ways to hold their own ..." — Namely, they were different and similar at the same time. —

Around the middle of his review, Galison quotes Feynman's last letter to his first wife, Arline, written after she died of tuberculosis in June 1945. The letter ends with the words, "P. S. Please excuse me my not mailing this — but I don't know your new address." This letter plainly and movingly conveys Feynman's sadness brought by Arline's death.

References

1. M. Feynman, ed. with an introduction, Perfectly Reasonable Deviations from the Beaten Track: The Letters of Richard P. Feynman (Basic Books, 2005).
2. P. Galison, "Letters from a hero: What made Richard Feynman so much more than a Nobel prizewinning physicist?" Nature, Vol. 436, p. 320 (2005).
3. R. P. Feynman, Surely You're Joking, Mr. Feynman!": Adventures of a Curious Character, as told to R. Leighton, ed. by E. Hutchings (W. W. Norton, paperbound 1997; hardbound 1985).
4. R. P. Feynman, R. B. Leighton and M. Sands, The Feynman Lectures on Physics (Addison Wesley, 1963).

Quotation from Einstein on Study

From the necessity of my job, I had been a subscriber to the RSICC Newsletter published monthly and distributed freely by Radiation Safety Information Computational Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. At the top of each issue of this newsletter, a quotation from a wise person of the past is given. I had used to copy it into my computer file. Since several years ago, the newsletter has been an online publication. Thus the copying of the quotation has become easy. However, an easy thing to do is not an attractive thing to do. So I have stopped copying the quotation of the newsletter.

The latest issue [1] of the newsletter carries a quotation from Einstein on study. I like it very much, so that I am citing it below:

Never regard study as a duty, but as the enviable opportunity to learn to know the liberating influence of beauty in the realm of the spirit for your own personal joy and to the profit of the community to which your later work belongs.--Albert Einstein

1. RSICC Newsletter No. 484 (June 2005).