A professional who conducts research into phases of physical phenomena, develops theories and laws on basis of observation and experiments, and devises methods to apply laws and theories of physics to industry, medicine, and other fields. Responsibilities include:

• Performs experiments with masers, lasers, cyclotrons, betatrons, telescopes, mass spectrometers, electron microscopes, and other equipment to observe structure and properties of matter, transformation and propagation of energy, relationships between matter and energy, and other physical phenomena.
• Describes and expresses observations and conclusions in mathematical terms.
• Devises procedures for physical testing of materials.
• Conducts instrumental analyses to determine physical properties of materials.
• May specialize in one or more branches of physics and be designated Physicist, Acoustics; Physicist, Astrophysics; Physicist, Atomic, Electronic And Molecular; Physicist, Cryogenics; Physicist, Electricity And Magnetism; Physicist, Fluids.
• May be designated. Responsibilities include:
• Physicist, Light And Optics; Physicist, Nuclear; Physicist, Plasma; Physicist, Solid Earth; Physicist, Solid State; Physicist, Thermodynamics.