Japanese Contributions to Modern Physics: From Yukawa to Nambu
Posted by Paul Halpern on 02/16 at 02:13 PM
(This essay appeared, in translated form, in the Japanese edition of my book Collider)
The Large Hadron Collider represents an expression of the quest for unity in nature, a tradition that dates back to the time of the ancients. In recent times, many theoretical physicists have sought to complete the puzzle of uniting the known forces into a single comprehensive theory of everything. In particular, three Japanese physicists have played an especially important and influential role in this search. Each received the Nobel Prize for his efforts.
The first, Hideki Yukawa, was instrumental in generalizing the inverse-square law of forces, applied to gravity and electromagnetism, into a new relationship, called the Yukawa potential, describing the force binding together the nucleus, now known as the strong force. His key prediction that forces are carried by exchange particles set out a search for new elementary particles and helped motivate the building of accelerators.
Another important development in understanding natural forces was the application of quantum principles to electrodynamics, independently completed by Sin-Itiro Tomonaga and the American theorists Richard Feynman and Julian Schwinger. Upon this success, physicists hoped to extend these ideas to other forces, which has proven especially challenging for the case of gravity.
A brilliant thinker who has pointed a possible way toward further unity is Yoichiro Nambu. Nambu developed the concept of spontaneous symmetry breaking, showing how natural balances can break down, like smooth water freezing into cracked ice. His work was further developed by the British physicist Peter Higgs and others, and has helped motivate the particle searches in the Large Hadron Collider.
Let us hope that the dreams of these and other great scientists are realized in the particle detectors of the Large Hadron Collider. It is only appropriate that this search for unity is being carried out by international groups of researchers, brought together by their hope of finding a complete explanation of how all forces and particles in the universe interact and how unification manifested itself during the time of the Big Bang.