Physics is the underlying science of all other sciences. The study of all fundamental forces and processes from the subatomic to the "astronomic" size scales is the purview of physics. For students of science other than physicists the purpose of learning physics is both the understanding of basic concepts and the application of problem solving skills developed during that process. For physics majors they may be preparing for careers from basic research, teaching, medicine, engineering, law, or a myriad of other careers where problem solving skills are valued. Current "hot topics" are energy and fusion research, astrophysics, atmospheric physics, lasers, plasmas, optics, nano-technology, biophysics and radiation.
All of the fields listed above as hot topics as well as solid state physics, atomic and molecular physics, low temperature phenomenon, chemical physics and as yet unknown new specialties are being developed at this very moment. Experimental physicists design and carry out experiments to discover new phenomena and to test existing theories and models. Theoretical physicists develop new models or adjust current models to fit observed phenomena. Both must have a thorough understanding of what the other does since their combined efforts lead to progress and understanding.
As indicated above, physicists find careers in industry, government, and universities doing teaching and research. Physics grads may also pursue patent law, bio technology research or many other seemingly unrelated areas because of their problem solving skills.