My Small Contribution to Feynman Stamp

I did not remember what I had written to recommend Richard Feynman for the U.S. postage stamp (see the previous story), but found a copy of the recommendation letter in the hard disk of my computer. I cite it below for the interest of the readers of my essays. I wrote about a relation between Feynman's wonderful work and the humble work of my coworker and me in the third paragraph. Though it is a minor relation, I believe that it made my letter unique.

July 13, 1996

Citizens Stamp Advisory Committee
L'Enfant Plaza, Washington D. C.

Dear Sir,

I am writing to urge you to support our wish that Richard Feynman should be honored with a commemorative postage stamp.

Richard Feynman shared the Nobel Prize in Physics with Julian Schwinger and Sin-Itiro Tomonaga for their work on relativistic quantum electrodynamics (QED). QED is an amazingly accurate theory about the behavior of elementary particles, and Feynman's contribution is especially unique in that he invented and used a method called "path integral approach," aided by diagrams that simply depicted different orders of physical processes (Feynman diagrams).

Not only have Feynman diagrams become the standard language of theories for elementary particles, atomic nuclei and condensed matter, but also they have had influences on workers in a broad area of applied sciences. For example, my coworker and I have been working in the field of radiation physics, and have developed a semi-empirical algorithm to evaluate dose distributions given by electron beams in multilayer absorbers. At first it seemed to be quite difficult to extend the algorithm beyond three layers. From Feynman diagrams, however, I hit upon using schematic diagrams to depict different possible paths of electrons that passed through boundaries between different media. Thus the extension of the algorithm to more layers became a simple task.

Japan's first Nobel laureate, Hideki Yukawa, was honored with a commemorative postage stamp of our country in 1985, which was the occasion of the jubilee of his meson theory. The second Nobel laureate, Sin-Itiro Tomonaga, will surely get the same commemoration soon. We heartily wish to see one of the sharers of the Nobel Prize with Tomonaga smiling on a postage stamp of U.S.A. Because of his amiable character and ingenuity on top of his memorable accomplishments, there are many fans of Richard Feynman in Japan.

Sincerely yours,
Tatsuo Tabata
Professor
Research Institute for Advanced Science and Technology
Osaka Prefecture University