Physicists and astronomers typically do the following:
Physicists explore the fundamental properties and laws that govern space, time, energy, and matter. Some physicists study theoretical areas, such as the fundamental properties of atoms and molecules and the evolution of the universe. Others design and perform experiments with sophisticated equipment such as particle accelerators, electron microscopes, and lasers. Many apply their knowledge of physics to practical areas, such as developing advanced materials and medical equipment.
Astronomers study planets, stars, galaxies, and other celestial bodies. They use ground-based equipment, such as radio and optical telescopes, and space-based equipment, such as the Hubble Space Telescope. Some astronomers focus their research on objects in our solar system, such as the sun or planets. Others study distant stars, galaxies, and phenomena such as neutron stars and black holes, and some monitor space debris that could interfere with satellite operations.
Many physicists and astronomers work in basic research with the aim of increasing scientific knowledge. These researchers may attempt to develop theories that better explain what gravity is or how the universe works or was formed. Other physicists and astronomers work in applied research. They use the knowledge gained from basic research to affect new developments in areas such as energy, electronics, communications, navigation, and medical technology. For example, because of the work of physicists, lasers are used in surgery and microwave ovens are used in most kitchens.
Astronomers and physicists typically work on research teams together with engineers, technicians, and other scientists. Some senior astronomers and physicists may be responsible for assigning tasks to other team members and monitoring their progress. They may also be responsible for finding funding for their projects and therefore may need to write applications for research grants.
Although all of physics involves the same fundamental principles, physicists generally specialize in one of many subfields. The following are examples of types of physicists:
Astrophysicists study the physics of the universe. "strophysics" is a term that is often used interchangeably with "astronomy."
Atomic, molecular, and optical physicists study atoms, simple molecules, electrons, and light, as well as the interactions among them. Some look for ways to control the states of individual atoms, because such control might allow for further miniaturization or might contribute toward the development of new materials or computer technology.
Condensed matter physicists study the physical properties of condensed phases of matter, such as liquids and solids. They study phenomena ranging from superconductivity to liquid crystals.
Medical physicists work in healthcare and use their knowledge of physics to develop new medical technologies and radiation-based treatments. For example, some develop better and safer radiation therapies for cancer patients. Others may develop more accurate imaging technologies that use various forms of radiant energy, such as magnetic resonance imaging (MRI) and ultrasound imaging.
Particle and nuclear physicists study the properties of atomic and subatomic particles, such as quarks, electrons, and nuclei, and the forces that cause their interactions.
Plasma physicists study plasmas, which are considered a distinct state of matter and occur naturally in stars and interplanetary space and artificially in neon signs and plasma screen televisions. Many plasma physicists study ways to create fusion reactors that might be a future source of energy.
Unlike physicists, astronomers cannot experiment on their subjects, because they are so far away that they cannot be touched or interacted with. Therefore, astronomers generally make observations or work on theory. Observational astronomers observe celestial objects and collect data on them. Theoretical astronomers analyze, model, and theorize about systems and how they work and evolve. Some astronomers specialize further into other subfields. The following are examples of types of astronomers who specialize by the objects and phenomena they study:
Cosmologists and extragalactic astronomers study the entire universe. They study the history, the creation and evolution, and the possible futures of the universe and its galaxies. These scientists have recently developed several theories important to the study of physics and astronomy, including string, dark-matter, and dark-energy theories.
Galactic, planetary, solar, and stellar astronomers study different phenomena that take place in the universe, specializing in certain parts of it. For example, solar astronomers study the sun, while stellar astronomers study other stars and associated phenomena.
High-energy astrophysicists collect and analyze x rays, gamma rays, and other forms of high-energy rays that can help locate and study black holes or neutron stars.
Observational astronomers and optical astronomers use optical telescopes to study their subjects.
Radio astronomers use radio telescopes to analyze the radio spectrum for data about their subjects.
Growing numbers of physicists work in interdisciplinary fields, such as biophysics, chemical physics, and geophysics. For more information, see the profiles on biochemists and biophysicists and geoscientists.
Many people with a physics or astronomy background become professors or teachers. For more information, see the profiles on high school teachers and postsecondary teachers.