Thermal radiation is defined as thermal (heat) energy transformations caused by the emission of electromagnetic waves from an emitting body. Thermal radiation summed over all wavelengths obeys the Stefan-Boltzmann law, which states that the radiation by a blackbody radiator per second per unit area is proportional to the fourth power of the absolute temperature. Mathematically, it is expressed as: P/A = T4 (in units of J/m 2 s), where P is the radiated power, A is the radiative area and is Stefan's constant, equal to 5.6703 x 10-8 watt/m 2 K4 . For radiating bodies other than ideal blackbody radiators, the expression is modified to: P/A = e T4 where e is the emissivity of the body; e = 1 for a blackbody. If the temperature of the radiating body is higher than that of its surroundings, the net radiation loss rate takes is given by: P = e A (T...