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.

漢字只適合風花雪月，不是科學的文字，難怪中國人玩漢字玩了幾千年，除了那些無聊的無病呻吟的東西外，幾乎沒有任何科學的建樹。如果把漢字單純地看作是個符號系統，那麼這個符號系統是非常不適合科學思維的，最適合科學思維的是那些形式簡單，條理清晰，演繹容易，組合便利的字母文字。