Chen Ning Yang was a world-renowned theoretical physicist whose groundbreaking contributions transformed modern physics. Born on September 22, 1922, in Hefei, Anhui Province, China, he received his early education at Tsinghua University before earning a fellowship to study at the University of Chicago in 1945. He completed his doctoral studies under Enrico Fermi, receiving his PhD in 1948 with a thesis on nuclear reactions and coincidence measurements. Yang's early academic career included significant positions at the Institute for Advanced Study at Princeton, establishing him as a rising star in theoretical physics. His rigorous training in symmetry principles and statistical mechanics laid the foundation for his revolutionary future discoveries.
Yang's most celebrated achievement came through his collaboration with Tsung-Dao Lee, challenging the fundamental assumption of parity conservation in weak nuclear interactions. Their 1956 theoretical work predicted that certain subatomic particle decays would violate mirror symmetry, a concept previously thought to be universally conserved like energy or charge. This paradigm-shifting discovery, confirmed by Chien-Shiung Wu's famous experiment, earned them the 1957 Nobel Prize in Physics, making Yang and Lee the first Chinese-born Nobel laureates. Additionally, Yang's collaboration with Robert Mills produced the Yang-Mills gauge theory, which became the mathematical foundation for the Standard Model of particle physics, alongside Maxwell's equations and Einstein's relativity. His work with Rodney Baxter on the Yang-Baxter equation further revolutionized statistical mechanics and quantum group theory.
Throughout his illustrious career, Yang made profound contributions across multiple domains including particle physics, statistical mechanics, and condensed matter physics, with his theories continuing to influence research decades later. His legacy as one of the greatest physicists of the twentieth century is cemented by how his work fundamentally reshaped our understanding of symmetry principles in nature. Yang's influence extended beyond research as he mentored generations of physicists and advocated for scientific collaboration between China and the United States. After a long and distinguished career that included his position as Albert Einstein Professor at SUNY Stony Brook, Yang returned to China in his later years. He passed away on October 18, 2025, in Beijing at the age of 103, leaving behind an enduring scientific legacy that continues to inspire physicists worldwide.
