I'm currently a phd student and am doing high energy particle physics. I am unsure about what I will do when I graduate, but I suspect I willl apply for postdoc positions. What I'm wondering is, let's say I do decide to stay in physics. Am I completely limited to a career in HEP physics, or could other options be open to me? It's not that I don't like HEP physics, but there are other areas that I quite like, and I'd like the option to work in certain places in the world where HEP physics is not being done but other types of physics are. If the answer is no, then what can a PhD-holding physicist do if he wishes to change his career path? How can they prove they have the relevant knowledge to findemployment in a different branch of physics? Do they have to do another masters or even another PhD? Or can they apply to jobs and demonstrate their competency in other ways?