Thermal Radiation

Thermal radiation is the process by which energy, in the form of electromagnetic radiation, is emitted by a heated surface in all directions. It travels directly to its point of absorption at the speed of light, without requiring an intervening medium.

There is a meaningful distinction between “thermal radiation” and “infrared radiation.” Although they can be used interchangeably in everyday language, they are not synonymous. Thermal radiation refers to electromagnetic radiation of any frequency generated by the thermal emission process, not limited to the infrared spectrum. In contrast, infrared radiation is electromagnetic radiation within a specific frequency range.