reemits

Reemits is the third-person singular present tense of the verb reemit, meaning to emit again or to cause to emit again. In scientific and technical writing, reemits describes the act or result of secondary emission, usually arising from an interaction that alters the energy state of the emitting system or the surrounding medium.

The term is used across physics, astronomy, and engineering to refer to energy re-emitted after initial emission. It is especially common in discussions of how materials, gases, or celestial bodies process incident radiation, and it often implies a shift in wavelength or direction compared to the primary emission.

In astronomy and astrophysics, reemission occurs when absorbed photons by dust grains or gas are emitted again, typically at infrared wavelengths, affecting observations and the thermal balance of galaxies and the interstellar medium. In quantum optics and spectroscopy, reemission describes photons released by excited atoms or molecules as they decay, underpinning phenomena such as fluorescence and spontaneous emission. In atmospheric science, reemitted infrared radiation by greenhouse gases contributes to the Earth's energy budget and climate dynamics.

In technology and communications, reemission can refer to secondary radiation produced by scattering objects or by antennas, influencing imaging, sensing, and signal propagation. The term is often used interchangeably with re-emission or simply emission, depending on the discipline.