Physics is a diverse area of study and in order to make sense of it scientists have been forced to focus their attention on one or two smaller areas of the discipline. This allows them to become experts in that narrow field, without getting bogged down in the sheer volume of knowledge that exists regarding the natural world. Below is a list by no comprehensive of different disciplines of physics. The list will be updated with new additions and definitions as appropriate. Acoustics the study of sound & sound waves

Astronomy the study of space Astrophysics the study of the physical properties of objects in space Atomic Physics the study of atoms, specifically the electron properties of the atom Biophysics the study of physics in living systems

Chaos the study of systems with strong sensitivity to initial conditions, so a slight change at the beginning quickly become major changes in the system Chemical Physics the study of physics in chemical systems

Computational Physics the application of numerical methods to solve physical problems for which a quantitative theory already exists Cosmology the study of the universe as a whole, including its origins and evolution Cryophysics / Cryogenics / Low Temperature Physics the study of physical properties in low temperature situations, far below the freezing point of water Crystallography the study of crystals and crystalline structures Electromagnetism the study of electrical and magnetic fields, which are two aspects of the same phenomenon Electronics the study of the flow of electrons, generally in a circuit Fluid Dynamics / Fluid Mechanics the study of the physical properties of fluids, specifically defined in this case to be liquids and gases Geophysics the study of the physical properties of the Earth High Energy Physics the study of physics in extremely high energy systems, generally within particle physics High Pressure Physics the study of physics in extremely high pressure systems, generally related to fluid dynamics Laser Physics the study of the physical properties of lasers Mathematical Physics applying mathematically rigorous methods to solving problems within physics Mechanics the study of the motion of bodies in a frame of reference Meteorology / Weather Physics the physics of the weather

Molecular Physics the study of physical properties of molecules Nanotechnology the science of building circuits and machines from single molecules and atoms Nuclear Physics the study of the physical properties of the atomic nucleus Optics / Light Physics the study of the physical properties of light Particle Physics the study of fundamental particles and the forces of their interaction Plasma Physics the study of matter in the plasma phase

Quantum Electrodynamics the study of how electrons and photons interact at the quantum mechanical level Quantum Mechanics / Quantum Physics the study of science where the smallest discrete values, or quanta, of matter and energy become relevant Quantum Optics the application of quantum physics to light Quantum Field Theory the application of quantum physics to fields, including the fundamental forces of the universe Quantum Gravity the application of quantum physics to gravity and unification of gravity with the other fundamental particle interactions

Relativity the study of systems displaying the properties of Einsteins theory of relativity, which generally involves moving at speeds very close to the speed of light Statistical Mechanics the study of large systems by statistically expanding the knowledge of smaller systems String Theory / Superstring Theory the study of the theory that all fundamental particles are vibrations of one-dimensional strings of energy, in a higher-dimensional universe Thermodynamics the physics of heat

Astronomy the study of space Astrophysics the study of the physical properties of objects in space Atomic Physics the study of atoms, specifically the electron properties of the atom Biophysics the study of physics in living systems

Chaos the study of systems with strong sensitivity to initial conditions, so a slight change at the beginning quickly become major changes in the system Chemical Physics the study of physics in chemical systems

Computational Physics the application of numerical methods to solve physical problems for which a quantitative theory already exists Cosmology the study of the universe as a whole, including its origins and evolution Cryophysics / Cryogenics / Low Temperature Physics the study of physical properties in low temperature situations, far below the freezing point of water Crystallography the study of crystals and crystalline structures Electromagnetism the study of electrical and magnetic fields, which are two aspects of the same phenomenon Electronics the study of the flow of electrons, generally in a circuit Fluid Dynamics / Fluid Mechanics the study of the physical properties of fluids, specifically defined in this case to be liquids and gases Geophysics the study of the physical properties of the Earth High Energy Physics the study of physics in extremely high energy systems, generally within particle physics High Pressure Physics the study of physics in extremely high pressure systems, generally related to fluid dynamics Laser Physics the study of the physical properties of lasers Mathematical Physics applying mathematically rigorous methods to solving problems within physics Mechanics the study of the motion of bodies in a frame of reference Meteorology / Weather Physics the physics of the weather

Molecular Physics the study of physical properties of molecules Nanotechnology the science of building circuits and machines from single molecules and atoms Nuclear Physics the study of the physical properties of the atomic nucleus Optics / Light Physics the study of the physical properties of light Particle Physics the study of fundamental particles and the forces of their interaction Plasma Physics the study of matter in the plasma phase

Quantum Electrodynamics the study of how electrons and photons interact at the quantum mechanical level Quantum Mechanics / Quantum Physics the study of science where the smallest discrete values, or quanta, of matter and energy become relevant Quantum Optics the application of quantum physics to light Quantum Field Theory the application of quantum physics to fields, including the fundamental forces of the universe Quantum Gravity the application of quantum physics to gravity and unification of gravity with the other fundamental particle interactions

Relativity the study of systems displaying the properties of Einsteins theory of relativity, which generally involves moving at speeds very close to the speed of light Statistical Mechanics the study of large systems by statistically expanding the knowledge of smaller systems String Theory / Superstring Theory the study of the theory that all fundamental particles are vibrations of one-dimensional strings of energy, in a higher-dimensional universe Thermodynamics the physics of heat