A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
In the aerospace context, a physicist is a scientist who specializes in the study of matter and energy and their interactions. Physicists work on understanding the fundamental laws that govern the universe, and they use this knowledge to develop new technologies and solve problems in a wide range of fields, including aerospace.
One example of a physicist in the aerospace context is an aerodynamicist who uses principles of physics, such as fluid dynamics and thermodynamics, to understand and optimize the performance of aircraft and other aerospace vehicles. They study the behavior of air and other fluids around an aircraft, and use this knowledge to design more efficient and stable aircraft.
Another example is a propulsion physicist who uses principles of physics to design and develop propulsion systems for aerospace vehicles. They study the behavior of gases and liquids under different conditions, and use this knowledge to design and optimize the performance of engines, rocket motors, and other propulsion systems.
Additionally, physicists in the aerospace field also work on developing new materials, studying space-related phenomena, and designing sensors and instruments that are used to gather data about the atmosphere, space and other celestial objects, as well as on developing guidance and navigation systems for aerospace vehicles, studying the effects of space environment on the aerospace vehicles.