Electromagnetic radiation (or "extreme") ultraviolet. UV, with X-ray and gamma radiation, are referred to as ionizing radiation due to the ability of photons of this radiation to produce ions and free radicals in materials (including living tissue). Since such radiation can severely damage life at energy levels that produce little heating, it is considered far more dangerous (in terms of damage-produced per unit of energy, or power) than the rest of the electromagnetic spectrum. The heat ray is an application of EMR that makes use of microwave frequencies to create an unpleasant heating effect in the upper layer of the skin. A
Greenhouse effect heated) "greenhouse" with a cover of rock salt (which is transparent to infrared) heats up an enclosure similarly to one with a glass cover. Thus greenhouses work primarily by preventing convective cooling. Heated greenhouses are yet another matter, having an internal source of heating they leak heat out, which must be prevented. So it again makes sense to try to prevent radiative cooling through the use of adequate glazing. The anti-greenhouse effect is a mechanism similar and symmetrical to the greenhouse effect: greenhouse effect is about atmosphere letting radiation in, while not letting thermal radiation out, which warms the body