Kirchhoff's law of thermal radiation

Kirchhoff's law of thermal radiation states that, at thermal equilibrium, a material's ability to emit radiation (its emissivity) is equal to its ability to absorb radiation of the same wavelength. In simple terms, good absorbers are also good emitters of thermal energy. This means that an object that easily absorbs heat will also efficiently emit heat when heated. The law helps explain how objects radiate energy, indicating a balance between absorption and emission. It’s fundamental in understanding thermal radiation processes in nature and engineering.