Hideki Yukawa's Lindau Lecture

Reading a Scientific American article on the 61st Annual Lindau Nobel Laureate Meeting [1], I have learned the home page The Nobel Laureate Meeting at Lindau [2]. Scrolling the page downwards, we see a link to the Lectures Online page. There we can listen to more than 100 lectures of Nobel Laureates online. Among those lectures, I have found Hideki Yukawa's speech at the 3rd Lindau Nobel Laureate Meeting (1953, 1st Meeting in Physics) entitled "Attempt at a Unified Theory of Elementary Particles." Instead of the abstract of his presentation, a brief introduction is given by the editor Anders Bárány.

Bárány writes that Yukawa's full written lecture can be found in a special publication of the journal Naturwissenschaftliche Rundschau from 1981 and that the printed version contains a number of rather complicated equations not shown during his speech in Lindau. The Japanese version of the full written lecture appeared in November 1953 issue of Shizen and was reprinted in the special number for Yukawa memorial of the same journal published in November 1981.

Here are essential words from Bárány's introduction:

This was a time when one of the main problems in physics was the large number of elementary particles detected in cosmic rays and in high-energy accelerators. [. . . T]he problem was that, as Yukawa phrased it in his lecture, "Powell discovered a great number of extra particles which I did not need." Today we have the Standard Model of particles and forces, through which all the “extra” particles can be classified and all the forces computed. But we still miss what Yukawa was looking for in his attempt to formulate a unified theory of elementary particles [. . .]

Yukawa's attempt at that time was in the direction of nonlocal field theory.

There was a rumor that Yukawa's spoken English had the intonation of the Kyoto dialect. Listening to his Lindau lecture, I do not think so. His voice in this talk sounds young (he was 46 years old at that time) and fairly similar to the voice of his son, Taka'aki, whom we can listen to in the narration of the video The Yukawa Story [3]. I also think that Yukawa's talk in English is more listenable than his lecture in Japanese at the classroom of the university.

I owe to Mr. M. M. for the information of the Japanese version of Yukawa's written Lindau lecture.

1. S. Mirsky, Noble Nobel faces: A week in Lindau, where scientists are celebrities. Scientific American (September 1, 2011); printed version, September issue, page 78 (2011).
2. The Nobel Laureate Meeting at Lindau: Educating, Inspiring, Connecting scientific Generations since 1951, www.lindau-nobel.org.
3. The Yukawa story, You Tube video (uploaded on December 23, 2009).