@CT1417 I’m curious, so maybe you can ask him for me. It seems like theoretical CS & applied mathematics are about the same thing. Or at least they would be at about the same location on the XKCD purity scale (https://xkcd.com/435/). I’d guess both would be at about the location of physics on the scale, for some aspects of physics. But, I’m also not all that well informed about the contents of each major.