So I'm going to be an undergrad at Caltech starting this September. Physics is my main interest, although I also like math and computer science. My main question is what to major in. I will obviously major in physics, but I am also considering doubling in either math or computer science. I am more into theoretical physics than experimental physics, which would lead me to believe that math would be better. But couldn't a knowledge of computer science also be beneficial even for theoretical physics? Also I feel like computer science would be a great backup if I got out of physics for any reason, even though I am not anticipating doing so now. Any insights into this would be greatly appreciated!