Here's my Mastodon post on the passing of Yang Chen-Ning, called Frank in the west.
Rest in Peace, Frank Yang!
I had the privilege to get my masters at his institute at SUNY that bears his name, although I did not meet him during my time there as he was visiting China at the time - my claim to Yang fame thus remains that I got to fill out my tax paperwork sitting in his office, and I think we stole one issue of CERN courier addressed to his name
While he got his Nobel prize for the prediction of parity violation, the context in which quantum field theorists and particle physicists will probably encounter his name most often is for Yang-Mills-Theory, the theoretical framework which describes the strong and weak interactions in the standard model of particle physics, named after Yang and Robert Mills who unfortunately died 26 years ago..
If you don't know it, you can imagine Yang-Mills-Theory as having several copies of the electromagnetic field ( eight in the case of the strong interactions, and three in the case of weak interactions) in parallel, and have them all interact with each other. There is a unique way to achieve this in four spacetime dimensions which allows for the dynamics observed in Gluons and the W, Z bosons with the photon, and that is Yang-Mills-Theory.
It would be fair to say that Yang-Mills-Theory is the foundation of how we understand most of the fundamental forces in modern physics.
Yang-Mills theory famously has the property that, unlike the photon in electrodynamics, it is forbidden for its bosons to possess any mass - it would be much easier to bestow mass upon the photon of electrodynamics via the Stückelberg mechanism (named after none other than Ernst Carl Gerlach Stückelberg von Breidenbach zu Breidenstein und Melsbach, unsung hero of quantum electrodynamics), but such shortcuts of generating mass are not possible in Yang-Mills-theory without seriously breaking things.
According to legend, this led to a historic clash between the Yang-Mills-team and acerbic father of quantum mechanics and pitiless axe of reason, Wolfgang Pauli, who let Yang-Mills-theory die from public humiliation after a talk by remarking that it predicts massless bosons which are clearly not present in nature.
What Wolfgang Pauli could not have known - the simplest and most elegant way to have masses for bosons in Yang-Mills-Theory, it turned out later, is the Higgs-mechanism, and the rest, as you know, is science history...
Rest in Peace, Frank Yang!
I had the privilege to get my masters at his institute at SUNY that bears his name, although I did not meet him during my time there as he was visiting China at the time - my claim to Yang fame thus remains that I got to fill out my tax paperwork sitting in his office, and I think we stole one issue of CERN courier addressed to his name
While he got his Nobel prize for the prediction of parity violation, the context in which quantum field theorists and particle physicists will probably encounter his name most often is for Yang-Mills-Theory, the theoretical framework which describes the strong and weak interactions in the standard model of particle physics, named after Yang and Robert Mills who unfortunately died 26 years ago..
If you don't know it, you can imagine Yang-Mills-Theory as having several copies of the electromagnetic field ( eight in the case of the strong interactions, and three in the case of weak interactions) in parallel, and have them all interact with each other. There is a unique way to achieve this in four spacetime dimensions which allows for the dynamics observed in Gluons and the W, Z bosons with the photon, and that is Yang-Mills-Theory.
It would be fair to say that Yang-Mills-Theory is the foundation of how we understand most of the fundamental forces in modern physics.
Yang-Mills theory famously has the property that, unlike the photon in electrodynamics, it is forbidden for its bosons to possess any mass - it would be much easier to bestow mass upon the photon of electrodynamics via the Stückelberg mechanism (named after none other than Ernst Carl Gerlach Stückelberg von Breidenbach zu Breidenstein und Melsbach, unsung hero of quantum electrodynamics), but such shortcuts of generating mass are not possible in Yang-Mills-theory without seriously breaking things.
According to legend, this led to a historic clash between the Yang-Mills-team and acerbic father of quantum mechanics and pitiless axe of reason, Wolfgang Pauli, who let Yang-Mills-theory die from public humiliation after a talk by remarking that it predicts massless bosons which are clearly not present in nature.
What Wolfgang Pauli could not have known - the simplest and most elegant way to have masses for bosons in Yang-Mills-Theory, it turned out later, is the Higgs-mechanism, and the rest, as you know, is science history...
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
