Some physicists specialize in a subdivision of one of these subfields. For example, within condensed matter physics, specialties include crystallography, semiconductors, and superconductivity. However, all physics involves the same fundamental principles, so specialties may overlap. Some physicists may switch from one subfield to another. Increasingly physicists work in combined fields such as biophysics, chemical physics, and geophysics.
Astronomy is another subfield of physics.
Astronomers study the sun, moon, planets, stars, and galaxies. They also apply their knowledge to problems in navigation and space flight. Astronomers is a specialty of Physicists. For more information on Astronomers, see that specialty occupation. Physicists is in the Engineering, Science, and Technologies Career Cluster.