He can teach physics in Chinese if he wants. But it will definitely not even close to his English lectures in terms of clarity and precision. Not to mention that most part of the physics have already being written in mathematical forms that are called equations. None of these equations are written in Chinese. It will be funny to even think in that way writing any equations in Chinese.

You said that your major is Philosophy. So it shouldn't be too hard for you to see why Hanzi is not suitable for science and engineering. Symbolics and logics are so closely related. That is too easy for anyone to understand except you who is major in philosophy.

汉字只适合风花雪月，不是科学的文字，难怪中国人玩汉字玩了几千年，除了那些无聊的无病呻吟的东西外，几乎没有任何科学的建树。如果把汉字单纯地看作是个符号系统，那么这个符号系统是非常不适合科学思维的，最适合科学思维的是那些形式简单，条理清晰，演绎容易，组合便利的字母文字。