Most secular studies are bitul Torah. As for the issue of making a living, Rav Shach said one should learn Torah until one is married, and then just take whatever job presents itself. [But Physics and Math would be considered as a part of learning Torah according to the Rambam in the Mishna Torah where he says one should divide the day into three: the Written Law, The Oral Law, and the Gemara- and he adds the subjects he brought in the first four chapters of Mishna Torah are in the category of Gemara] [The Rambam and Ibn Pakuda also hold this idea with Metaphysics. What Ibn Pakuda means is clear--right there on the first page of the Chovot Levavot. But later on Metaphysics went beyond Plato and Aristotle to include Kant and Hegel.
