  Professor Chen Ning Yang has made seminal and influential contributions in
many different areas in theoretical physics. This talk focuses on his
contributions in statistical mechanics, a field in which Professor Yang has
held a continual interest for over sixty years. His Master's thesis was on a
theory of binary alloys with multi-site interactions, some 30 years before
others studied the problem. Likewise, his other works opened the door and led
to subsequent developments in many areas of modern day statistical mechanics
and mathematical physics. He made seminal contributions in a wide array of
topics, ranging from the fundamental theory of phase transitions, the Ising
model, Heisenberg spin chains, lattice models, and the Yang-Baxter equation, to
the emergence of Yangian in quantum groups. These topics and their
ramifications will be discussed in this talk.
