I'm heading into my junior year of a physics degree, which means I have about one more year to decide on what graduate programs to apply to. The thing that scares me, though, is that the more I learn, the harder it is for me to narrow down what I want to do. So far, I'm more interested in theory than experiment, and I think I've eliminated materials science. Some topics I'm interested in include atmospheric physics, climate science, astronomy/astrophysics, particle physics, and nuclear engineering. This is not an all-inclusive list. Things like geophysics interest me, but I haven't looked into that as much. For those of you who went (or are currently going) to grad school, at what point did you decide on what programs to apply for? Did you have a good idea by your junior year? Did you kinda just wing it as you went along? Did you apply to a bunch and just specialize in whatever you were accepted to? A second question is what are some methods of narrowing it down? I don't want to be paralyzed by too many choices.