Equilibrium Pressure

red ball Particles:  Pressure is a function of state.


yellow ball Force per unit area of the wall is a bulk property;

independent of the shape of the container and potentials at the wall

independent of the dynamics of the particles (momentum integrations)

yellow ball For a dilute gas:     

red ball Radiation:  Photon density is temperature dependent:

Stefan-Boltzmann law of black-body pressure: