I'm an undergraduate freshman in the United States majoring in physics, but I am also interested in several other fields of research. I find many questions in biology and geology interesting. I'd like to explore mathematics. There are questions about materials that would be answered through research in chemistry, and there are questions in astronomy and cosmology that I'd be interested in getting involved with.
However, there are only so many opportunities to do research as an undergrad. Would it be limiting at all when applying to grad schools for most of your research experience to be outside of your graduate field of study (physics)?