Physics is the basic science that underlies all of the physical sciences and influences most of the biological sciences. It treats matter, energy, and interactions at the fundamental level. Its subdisciplines include accelerator physics, acoustics, astrophysics, atomic physics, biophysics, condensed-matter physics both hard and soft, elementary-particle physics, general relativity, geophysics, gravity, low-temperature physics, medical physics, nuclear physics, optics, plasma physics, polymer physics, and radiation physics. Physics is a laboratory-based science. Experiments reveal the observable properties of the natural world, and theories provide an understanding of the observations. Mathematics serves as the essential language for the analysis of experiment and theory.
The work that physicists do can be classified as basic (fundamental) or applied. The scientist doing basic research typically works in a university or national laboratory, and is interested in learning about the fundamental processes of nature. The applied physicist wants to develop uses for knowledge through technological advances, and is employed most often in an industrial setting (but there are certainly exceptions to both of these statements).
Physicists usually choose to be either experimentalists or theorists. The experimenter uses apparatuses designed to test hypotheses and theories, to make unexpected discoveries of new phenomena, or to develop new applications of ideas. The theorist uses that data to develop new explanations, hypotheses, or theories. Occasionally a particularly broad scientist can act as both experimentalist and theorist. Physicists may also use the computer to simulate a physical system and generate data from observations of the simulation in order to gain new insights into real systems.
Physics is a constantly changing science with aspects which sometimes cross over into other disciplines. Often a field becomes very exciting and physicists pursue it vigorously. After the fundamental principles are established, a particular field may evolve into another discipline for further exploration. Thus, much of the physics of yesterday is now regarded as part of chemistry or engineering. It is interesting to conjecture how the physics of today may evolve in the decades to come. Our interdisciplinary Applied track was designed recognizing that scientists are often interested in fields that involve more than one discipline (or major).