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  2. Ultraviolet - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet

    Ultraviolet (UV) light is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and ...

  3. Electromagnetic radiation and health - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation...

    Environment portal. Ecology portal. v. t. e. Electromagnetic radiation can be classified into two types: ionizing radiation and non-ionizing radiation, based on the capability of a single photon with more than 10 eV energy to ionize atoms or break chemical bonds. [1] Extreme ultraviolet and higher frequencies, such as X-rays or gamma rays are ...

  4. Non-ionizing radiation - Wikipedia

    en.wikipedia.org/wiki/Non-ionizing_radiation

    A common example of such radiation is sunlight, which is thermal radiation from the Sun's photosphere and which contains enough ultraviolet light to cause ionization in many molecules and atoms. An extreme example is the flash from the detonation of a nuclear weapon , which emits a large number of ionizing X-rays purely as a product of heating ...

  5. Sunlight - Wikipedia

    en.wikipedia.org/wiki/Sunlight

    Taken on 20 October 1968 from Apollo 7. Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere as daylight when the Sun is above the horizon.

  6. Ultraviolet index - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet_index

    The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn -producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general public. The UV index is designed as an open-ended linear scale, directly proportional to the ...

  7. Light pollution - Wikipedia

    en.wikipedia.org/wiki/Light_pollution

    Light pollution is the presence of any unwanted, inappropriate, or excessive artificial lighting. [ 1 ][ 2 ] In a descriptive sense, the term light pollution refers to the effects of any poorly implemented lighting sources, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or ...

  8. Radiation - Wikipedia

    en.wikipedia.org/wiki/Radiation

    In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. [ 1 ][ 2 ] This includes: electromagnetic radiation consisting of photons, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) particle radiation consisting of ...

  9. UV-B lamps - Wikipedia

    en.wikipedia.org/wiki/UV-B_lamps

    UV-B lamps are lamps that emit a spectrum of ultraviolet light with wavelengths ranging from 290–320 nanometers. This spectrum is also commonly called the biological spectrum due to the human body's sensitivity to light of such a wavelength. [ 1 ] UV-B light does not tan the skin very much, compared to the UV-A lamps that are used in tanning ...