Yang was born inHefei, Anhui, China, on 1 October 1922.[5] His mother was Luo Meng-hua and his father,Ko-Chuen Yang [zh] (楊克純; 1896–1973), was a mathematician.[6][7]
Yang attended elementary school and high school in Beijing, and in the autumn of 1937 his family moved toHefei after theJapanese invaded China.[8] In 1938 they moved toKunming,[8] Yunnan, whereNational Southwestern Associated University was located. In the same year, as a second-year student, Yang passed the entrance examination and studied at National Southwestern Associated University. He received a Bachelor of Science in 1942,[3] with his thesis on the application ofgroup theory to molecular spectra, under the supervision ofTa-You Wu.[6]
Yang continued to study graduate courses there for two years under the supervision ofWang Zhuxi (J.S. Wang), working on statistical mechanics. In 1944, he received a Master of Science fromNational Tsing Hua University, which had moved to Kunming during the Sino-Japanese War (1937–1945).[3] Yang was then awarded a scholarship from theBoxer Indemnity Scholarship Program, set up by the United States government using part of the money China had been forced to pay following theBoxer Rebellion.[9] His departure for the United States was delayed for one year, during which time he taught in a middle school as a teacher and studied field theory.[6]
Yang remained at theUniversity of Chicago for a year as an assistant toEnrico Fermi.[8] In 1949 he was invited to do his research at theInstitute for Advanced Study inPrinceton, New Jersey, where he began a period of fruitful collaboration withTsung-Dao Lee.[8] Lee and Yang published 32 papers together.[8] He was made a permanent member of the Institute in 1952, and full professor in 1955. In 1963,Princeton University Press published his textbook,Elementary Particles. In 1965 he moved toStony Brook University, where he was named the Albert Einstein Professor of Physics and the first director of the newly founded Institute for Theoretical Physics. Today this institute is known as theC. N. Yang Institute for Theoretical Physics.[3] Yang retired from Stony Brook University in 1999.[10]
Yang visited the Chinese mainland in 1971 for the first time after the thaw in China–US relations, and subsequently worked to help the Chinese physics community rebuild the research atmosphere,[11] which later eroded due to political movements during theCultural Revolution.[11] After retiring from Stony Brook, he returned to Beijing as an honorary director ofTsinghua University,[11] where he was the first Huang Jibei-Lu Kaiqun Professor at theCenter for Advanced Study (CASTU).[12] He was also one of the twoShaw Prize Founding Members and was a Distinguished Professor-at-Large at theChinese University of Hong Kong.[13]
Yang married Tu Chih-li (simplified Chinese:杜致礼;traditional Chinese:杜致禮;pinyin:Dù Zhìlǐ), a teacher, in 1950; they had two sons and a daughter together. His father-in-law was theKuomintang generalDu Yuming. Tu died in October 2003. In January 2005, Yang married Weng Fan (Chinese:翁帆;pinyin:Wēng Fān), a university student. They met in 1995 at a physics seminar; the couple reestablished contact in February 2004. Yang called Weng, who is 54 years his junior, his "final blessing from God".[16]
Yang obtained U.S. citizenship during his research within the country. According to the state-run Xinhua News Agency, Yang said the decision was painful as his father never forgave him for that. According to Xinhua, he formally renounced his American citizenship in late 2015, while acknowledging the U.S. was a beautiful country that gave him good opportunities to study science.[17][18]
His son Guangnuo was a computer scientist.[19] His second son Guangyu is an astronomer and his daughter Youli is a doctor.[20]
Yangturned 100 on 1 October 2022,[21] and died in Beijing on 18 October 2025, at the age of 103.[22][8] The day after the announcement of his death, people gathered and waited in line at Tsinghua University to pay tributes to Yang.[23]
Yang is known for having opposed the construction of theCircular Electron Positron Collider (CEPC), a 100 km circumference particle collider in China that would study theHiggs boson.[24] He catalogued the project as "guess" work and without guaranteed results. Yang said that "even if they see something with the machine, it's not going to benefit the life of Chinese people any sooner."[24]
His first two papers (1944, 1945) were the result of his master thesis on statistical physics, supervised byJ. S. Wang.[26]
At the University of Chicago, Yang first spent twenty months working in an accelerator lab, but found he was not good atexperimental physics and switched back to theory. His doctoral thesis was about an atomic beam apparatus for measuring thenuclear quadrupole resonance of sodium.[27]
Later, Yang worked on particle phenomenology; a well-known work was the Fermi–Yang model of 1949, treating thepion as a bound nucleon–antinucleon pair.[28]
Yang is well known for his 1953 collaboration withRobert Mills in developingnon-abeliangauge theory, widely known as theYang–Mills theory.[29] The idea was generally conceived by Yang while the novice scientist Mills assisted him as Mills explained:[30]
During the academic year 1953–54, Yang was a visitor toBrookhaven National Laboratory ... I was at Brookhaven also ... and was assigned to the same office as Yang. Yang, who demonstrated on a number of occasions his generosity to physicists beginning their careers, told me about his idea of generalizing gauge invariance and we discussed it at some length ... I was able to contribute something to the discussions, especially with regard to the quantization procedures, and to a small degree in working out the formalism; however, the key ideas were Yang's.
The foundation for the current understanding of how subatomic particles interact is a contribution which has restructured modern physics and mathematics.
In 1956, he and T. D. Lee analyzed a problem known as the τ–θ puzzle, in which a particle called θ decayed into twopions and a particle τ into three pions, the two decays with differentparity symmetry.[32] However the two particles were not distinguishable.[32] Lee and Yang proposed that, in theweak interaction,parity symmetry was not conserved and that it was the same particle (now known as thekaon K+).[32] To test if weak interaction conserved parity, Lee contactedChien-Shiung Wu's team at the National Bureau of Standards in Washington.Wu experiment experimentally verified the theory and the results were announced early in a press conference.[32] The results were also confirmed by two other independent experiments byValentine Telegdi andJerome Isaac Friedman at theUniversity of Chicago and byRichard Garwin andLeon M. Lederman atColumbia University.[32] All three experiments published their results in early 1957.[32] That year, Yang and Lee received the 1957Nobel Prize in Physics for this parity violation theory, which brought revolutionary change to the field of particle physics.[4]
On Yang's retirement from SUNY in 1999,Freeman Dyson called Yang "the pre-eminent stylist" of 20th-century physics alongsideAlbert Einstein andPaul Dirac, citing how Yang "turns his least important calculations into miniature works of art, and turns his deeper speculations into masterpieces."[8] In 2009, Dyson wrote:[25]
Yang took[Hermann] Weyl's place as the leading bird among my generation of physicists ... With non-Abelian gauge fields generating nontrivial Lie algebras, the possible forms of interaction between fields become unique, so that symmetry dictates interaction. This idea is Yang's greatest contribution to physics. It is a contribution of a bird flying high over the rain forest of little problems in which most of us spend our lives.
In 2012, there were celebrations for Yang's 90th birthday. TheChinese University of Hong Kong hosted a scientific conference and dinner banquet to announce the creation of the CN Yang archive.[36][37] PhysicistKenneth Young opened the ceremony.[37] Yang also received a black cube from Tsinghua University[38] with 13 of his seminal contributions engraved on the faces of the cube. On the cube is also written "Congratulations on Professor Chen Ning Yang's 90th birthday" in Chinese. The cube also includes an ancient Chinese poem used by Yang in his 2013Selected Papers and Commentaries, it reads:[25]
A piece of literature Is meant for the millennium But its ups and downs are known Already in the author's heart
Yang–Baxter equation (1967): consistent condition for a one-dimensional factorized scattering many-body system, which resurrected the interest in theBethe ansatz and allowed to better description of 1D fermions.[41][25]
Finite temperature (1969): for the Yang–Yang thermodynamics formalism for 1D bosons, in collaboration with his brotherChen-Ping Yang (1930–2018[42]).[43][25] The predictions of this formalism where demonstrated in 2008 usingultracold atoms.[38]
OLDRO (1962): for his development of the concept of off-diagonal long-range order (OLDRO) that characterizesmacroscopic quantum phenomena like superconductivity and superfluidity.[45][25]
Particle physics:
Parity non-conservation (1956): for predicting the violation ofparity symmetry with Lee, for which they were awarded the Nobel Prize in Physics in 1957.[25]
Neutrino experiment (1960): for Lee and Yang paper on that proposed to study the weak interaction with high energy neutrinos. This work promoted various neutrino experiments.[25][47]
CP nonconservation (1964): for his paper onCP violation, in collaboration with T. T. Wu.[48][25]
Yang was the first president of the Association of Asia Pacific Physical Societies (AAPPS) when it was established in 1989.[70] In 1997, the AAPPS created the C. N. Yang Award in his honor to highlight young researchers.[71]
^Li, Bing-An;Deng, Yuefan."Biography of C.N. Yang"(PDF).Archived(PDF) from the original on 7 January 2021. Retrieved11 September 2007.His birth date was erroneously recorded as September 22, 1922 in his 1945 passport. He has since used this incorrect date on all subsequent official documents.
^abcLi, Bing-An; Deng, Yuefan (1992)."Chen Ning Yang"(PDF).Biographies of Contemporary Chinese Scientists.3.Archived(PDF) from the original on 7 January 2021. Retrieved11 September 2007.
Yang, C. N. (1963) [1961].Elementary Particles: A Short History of Some Discoveries in Atomic Physics. Princeton, NJ: Princeton University Press.ASINB000E1CBGG.
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