Plasma is a state of matter in which atoms or molecules are ionized, meaning that they have lost or gained electrons and have become electrically charged. It is often referred to as the fourth state of matter, after solid, liquid, and gas.
The most important equation in plasma physics is the Boltzmann equation, which describes the behavior of a plasma in terms of the distribution of particles with different velocities and energies.
Statistical mechanics (stat mech) deals with the behavior and properties of a large number of particles in a plasma, while fluid dynamics focuses on the motion and interactions of the plasma as a whole. Electrodynamics is concerned with the electromagnetic forces and fields that govern the behavior of charged particles in a plasma.
Plasma physics has many practical applications, including plasma TVs, fluorescent lights, and fusion reactors. It is also used in various industrial processes, such as plasma cutting, welding, and surface treatments.
Plasma is the most common state of matter in the universe, and many astronomical phenomena, such as stars and galaxies, involve plasma. Therefore, studying plasma physics helps us gain a better understanding of these cosmic processes and the evolution of the universe.