Hello PF community, My name is Charlie Johnson. I just graduated from Stanford where I did a B.S. in Engineering Physics. I am studying for the Physics GRE and planning to apply to PhD programs this Fall. I have many interests both in and outside of school, and so I find it difficult to choose a research area. I spent one summer doing nanofabrication, one summer programming, and one summer doing Terahertz research. I liked the Terahertz research because I had more independence compared to my nanofab research, where I was more of an assistant. I am considering either trying out Atomic, Molecular, and Optical physics, mostly because it is new and exciting and involves lasers. I like that it has the potential to test novel physics. On the other hand, as a person I am very passionate about the environment and energy issues, so I am also potentially interested in nanoscience to study something along the lines of energy storage and conversion. This leads me to two questions. 1. Should I apply for Physics or Applied Physics PhD programs? My sense is that it is harder to get into Physics programs, so I am leaning towards applying to AP, at least at places like Stanford, Cal, and Harvard. Will either one limit my flexibility to find a research advisor? 2. What should I say about my research interests in my applications? I am weary of sounding too unfocused about my interests, even though it is probably true. How much flexibility will I have to explore when I arrive at a grad school? My understanding is that you can fit in 2-3 lab rotations in the first year, but is it a bad idea to explore vastly different areas in lab rotations? Any advice on this general question would be much appreciated. I love science, and I want to feel that my work has meaning, but I also love to understand things in a fundamental way.