non-ionizing radiation

Electromagnetic radiation with enough energy to move or heat atoms but not enough to strip their electrons (to “ionize”). It includes radio waves, microwaves, infrared, visible light, and lower-frequency ultraviolet — and is the basis of all wireless communication. Radio-frequency signals can also be used for sensing: research systems use ordinary Wi-Fi and radar (both non-ionizing) to detect motion and even coarse human figures through walls. Contrast with ionizing radiation (X-rays, gamma rays), which carries enough energy to damage DNA.

Related terms: electromagnetic field, Directed-energy, microwave auditory effect, hardware, optogenetics

Sources: Wi-Vi: seeing through walls with Wi-Fi — MIT; Household radar sees through walls — IEEE Spectrum