I am a college student, I love physics and in one of my physics class, I got an assignment in which students have to make a research proposal in a particular area in physics. I initially choose interstellar travel, how to make interstellar travel faster and more than ever, but my professor said that the topic is not testable. For the proposal I have to develop a clear and concise problem stated that is testable. My second option for the research was atomic and molecular physics, but I am so confused how do I narrow this huge topic down? Also, I need some cool topic suggestions?