"Yang-Mills Theory is a revolutionary scientific theory; it charts the direction for the most fundamental problem in physics. Its stature and influence are synonymous to Newton’s Laws of Mechanics, Maxwell’s electromagnetism theory and Einstein’s theory of relativity, among others."
Prof. K K Phua,
Chairman and Managing Editor of World Scientific
n the 50th anniversary of Yang-Mills Theory, World Scientific looks back at the developments and achievements in elementary particle physics that ensued from that beautiful idea through the eyes of an international team of experts. Each of them, who has left his mark on the developments of the remarkable theory, contributes essays or more detailed technical accounts to an invaluable volume that is to hit bookshelves soon.
Professor Gerardus ’t Hooft, himself a major player in the development of Yang-Mills Theory, edits the book. World Scientific speaks with this Nobel Laureate about the theory, the upcoming book and more.
Why have you decided to edit a volume on Yang-Mills Theory this time round?
Chen Ning Yang and Robert Mills made a momentous discovery 50 years ago. It attested to the fact that the notion of electric and magnetic fields, which describe well-known forces among fundamental particles of matter, could be generalized in a very natural manner to describe much more, different kinds of forces.
In the early days, it was not understood how these forces manifest themselves when elementary particles interact. This was discovered, in bits and pieces, during the years that followed. While many different approaches to describe the forces between particles failed, the Yang-Mills approach became victorious. This led to what we now call the “Standard Model” of the fundamental particles in the first 25 years after the discovery of Yang-Mills, and in the next 25 years, this model was refined and checked experimentally. We are looking back to a magnificent development in science that we wish to celebrate.
You were awarded the Nobel Prize for Physics in 1999. How has the award changed your career and even your life?
Receiving the Nobel Prize is a wonderful thing in our field of science. I regard it as recognition for my work from the entire Physics community. It is somewhat comparable to winning an Olympic medal, except that — as we all like to believe — this is a reward for contributions to progress in science. Such contributions will have much more lasting effects on the future of the human race than being a fraction of a second faster than a competitor.
Are you still conducting active research these days and which area(s) are you focusing on?
Yes, I am doing active research — this is what a scientist's life is about. I am very much attracted to the most basic questions of our field. It is not well understood how to reconcile the Theory of General Relativity with Quantum Mechanics, although we know that both doctrines somehow apply to the world that we live in. But there are also more technical questions concerning the strong interactions among sub-nuclear particles that require more elegant solutions than the ones known today.
Who has the most influence on you in your research in Physics?
There were several scientists in my family. I learned a lot from my uncle, a theoretical physicist. (Editor’s note: Prof. ’t Hooft, who aspires to be “a man who knows everything” at a tender age of eight, has science in his blood. In 1953, his granduncle, Frits Zernike, was awarded a Nobel Prize for work that had led him to the invention of the phase contrast microscope. His uncle, Nicolaas Godfried van Kampen, was appointed Professor of Theoretical Physics at the State University of Utrech.)