Sin-Itiro Tomonaga

On October 27, 1940, he married Ryoko Sekiguchi. The couple had two sons and a daughter.

Tomonaga suffered from throat cancer and passed away on July 8, 1979, in Tokyo. His remains were interred in the ‘Tama Reien Cemetery’ in Tokyo.

He was born on March 31, 1906, in Tokyo, Japan, to Tomonaga Sanjūrō and Hide Tomonaga as their second child and the eldest son. His father was a philosopher who served as a professor at ‘Shinshu University’ in Tokyo at the time of his birth.

The family relocated to Kyoto in 1913 where his father went on to serve the ‘Kyoto Imperial University’ as a professor of philosophy.

Since then he was raised in Kyoto where he joined ‘Kyoto Imperial University’ in 1926, the second oldest university of Japan and one of its National Seven Universities. It has produced ten ‘Nobel Prize’ Laureates including Hideki Yukawa, who was a classmate of Tomonaga during his undergraduate days.

In 1929 he earned Rigakushi that is a bachelor degree in physics from the university and during served as an assistant for three years. However his experience at the university was not a fulfilling one and that was accounted by him in “My Teachers, My Friends”.

Thereafter in April 1932 he joined the group of Japanese physicist Dr. Yoshio Nishina who was called ‘the founding father of modern physics research in Japan’, in latter’s Nishina Laboratory at RIKEN, a large research institute in Japan. There under the tutelage of Dr. Nishina he began working on quantum electrodynamics and completed a paper on photoelectric pair creation.

In 1940 he focussed on the meson theory and to analyse composition of meson cloud that exist around the nucleon he developed the intermediate coupling theory.

In 1941 he became a Professor of Physics at ‘Tokyo Bunrika University’.

He began serving as a part-time lecturer at ‘Tokyo Imperial University’ in 1944 and also conducted research for the navy.

During the ‘Second World War’ he studied meson theory, magnetron and his "super-many-time" theory. He worked on the theory of microwave circuits and wave guides, particularly on the concept of magnetron oscillator that is applied to produce short radio waves for radar. His contributing work on magnetron fetched him the ‘Japan Academy Prize’ along with Masao Kotani in 1948.

In 1948, Tomonaga and his students re-considered and analysed a 1939 paper of American theoretical physicist Sidney Dancoff in which the latter made effort but remained unsuccessful in showing that the infinities that arose in quantum electrodynamics can be cancelled and can give finite results.

He was jointly awarded the ‘Nobel Prize in Physics’ in 1965 along with Julian Schwinger and Richard Feynman.