How does radiation transfer heat energy?

Question

Lincoln Adams · Accepted Answer

Radiation transfers heat energy through photons.

All matter with a temperature above the absolute temperature of #0 K# emits thermal radiation, which is an electromagnetic radiation generated by the internal collision of particles in a matter. Like all electromagnetic radiations, thermal radiation propagates through space without requiring a medium, which is why heat from the Sun can reach Earth. Inter-atomic collisions between charged particles produce thermal radiations because they carry energy away from the emitting object in the form of electromagnetic radiation. This energy can be absorbed by other distant objects, which raises the internal energy of those objects' particles and causes those particles to move faster and collide more frequently, releasing energy as heat and raising the object's temperature. Reflective mirrors are used in solar power generation to concentrate thermal radiation on a focal point, unlike other methods of heat transfer such as conduction or convection. The rate of heat energy through radiation can be calculated using the Stefan-Boltzmann Constant. #Q = epsilon sigma T^4# where #Q# is heat flux, #epsilon# is the emissivity and #sigma# is the Stefan-Boltzmann constant and #T# is the absolute temperature. The transfer of heat between two radiant bodies can be calculated using #Q = epsilon sigma (T_a^4-T_b^4)#.

Parker Albertson · Answer

undefined In contrast to conduction or convection, radiation requires no medium to work; instead, it transfers heat energy through electromagnetic waves, such as infrared radiation. When an object absorbs radiation, its molecules gain kinetic energy, raising its temperature.