Sin-Itiro Tomonaga was a pioneer in the field of quantum electrodynamics, a broad theory that uses principles from quantum mechanics and special relativity to explain a wide variety of physical phenomena. He developed a theory about subatomic particles that was consistent with the relativity theory about the same time that Richard P. Feynman and Julian Schwinger independently reached similar solutions. The three were jointly awarded the 1965 Nobel Prize in physics for their efforts in quantum theory.

Sin-Itiro (also transliterated as Sin-Ichiro) Tomonaga was born in Tokyo on March 31, 1906, to Sanjuro and Hide Tomonaga. When Sin-Itiro was a child, his family moved to Kyoto, where his father had been appointed professor of philosophy at the Kyoto Imperial University. Sin-Itiro enrolled at Kyoto's prestigious Third High School where he was a classmate of Hideki Yukawa , later to become Japan's first Nobel Prize winner (in the field of physics) in 1949. After...