Which method of heat transfer is involved in radiation?

Radiation is the method of heat transfer that involves the emission of infrared energy. This process does not require a medium, such as air or water, to transfer heat. Instead, heat energy is transferred through electromagnetic waves, primarily in the infrared spectrum. This is why radiation can occur in a vacuum, as it relies solely on the emission of energy from a surface or body, which can then be absorbed by other surfaces at a distance.

In other methods of heat transfer, such as conduction and convection, physical contact or the movement of a fluid is necessary for the transfer of heat. For instance, conduction requires direct contact between materials to transfer thermal energy, while convection involves the movement of air or other fluids to transfer heat. Liquid evaporation is related to latent heat transfer, where heat is absorbed or released during a phase change, but it does not pertain to the concept of radiation. Thus, the correct identification of radiation as the emission of infrared energy underscores its unique nature in the heat transfer processes.