consider a spherical shell of radius R at temparature T. The black body radiation inside it can be considered as an ideal gas of photon with internal energy per unit volume u=u/V is directly proportional to T4 and pressure P=1/3×U/V . If the shell now undergoes an adiabatic expansion the relation between T and R is
consider a spherical shell of radius R at temparature T. The black body radiation inside it can be considered as an ideal gas of photon with internal energy per unit volume u=u/V is directly proportional to T4 and pressure P=1/3×U/V . If the shell now undergoes an adiabatic expansion the relation between T and R is