I am currently a sophomore studying Physics at University, I have taken various Mathematic courses and Physics topic, and now that summer break is approaching I will love to expand my fields of expertise in both Mathematics and Physics, as I am trying to decide what field is my favourite for future work and research. My questions are, first how do you decide the field to work in, or what are the features you look for?, and secondly what fields do you recommend to look at?, and books, videos, or courses of reference for me to look through in summer. #science source