This is an introduction to Quantum Field Theory. QFT is a powerful tool that explains many phenomena. High energy people care about it (Standard Model); Condensed matter people care about it (superconductor, topological material); mathematicians care about it (topological invariant). QFT is indeed a subject by itself. The main goal of this class is not to teach you how to compute anomalous magnetic dipole moment (https://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment) (one of the most accurate predictions in physics), but to introduce you different ways to think about physics. So I will give motivations what QFT means, why it works, how is it different from other theories... (Hopefully, I will update with a more detailed outline.) **Caution:** This topic is rather difficult even for graduate students and professors. (There are also much ongoing research just about this topic) I will try my best to explain them. But be prepared to be confused/surprised!

An introduction to phonological system of Chinese around a thousand years ago. We will cover the consonants and vowels with some discussions of sound changes across the time.