The domains of physics

Physics is divided in to four major domain with respect to size and speed.

•         Particle size more than a nanometer and in less speed compared to speed of light – classical mechanics.
•         Particle size less than a nanometer (near to size of atom) and in less speed compared to speed of light – quantum mechanics.
•         Particle size more than a nanometer and in speed comparable to speed of light – relativistic mechanics.
•         Particle size less than a nanometer (near to size of atom) and in speed comparable to speed of light – quantum field theory.

Any type of study under physics will come under this four categories.

With respect to energy:

•         Milli electron volt to few electron volts  -  solid state physics
•         Kilo electron volt to million electron volt  - nuclear physics
•         Million electron volt to Giga electron volt  - particle physics

With respect to phase:

•         Solid state  - solid state physics
•         Liquid state – fluid dynamics
•        Gaseous state – kinematics

To study:

•        Light – optics
•        Sound – acoustics
•         Heat- thermodynamics
•         More number of particles – statistics
•        Magnet – magnetism
•         Current – electrodynamics
•         Movement – mechanics
•         Cosmos – cosmology
•         Space and celestial bodies – astrophysics

In physics we have n number of interdisciplinary fields, but everything fall under the above discussed types.

Example: electronics will fall in solid state physics and electrodynamics