Based on observations and analysis, they attempt to discover the laws that describe the forces of nature, such as gravity, electromagnetism, and nuclear interactions. They also find ways to apply physical laws and theories to problems in nuclear energy, electronics, optics, materials, communications, aerospace technology, and medical instrumentation. Astronomy is sometimes considered a subfield of physics. Astronomers use the principles of physics and mathematics to learn about the fundamental nature of the universe, including the sun, moon, planets, stars, and galaxies. They apply their knowledge to problems in navigation and space flight.
Most physicists work in research and development.
Some do basic research to increase scientific knowledge. For example, they investigate the structure of the atom or the nature of gravity. Physicists who conduct applied research build upon the discoveries made through basic research and work to develop new devices, products, and processes. For instance, basic research in solid-state physics led to the development of transistors and then to the integrated circuits used in computers. Physicists also design research equipment.