Search results
Results From The WOW.Com Content Network
Ultraviolet radiation, also known as simply UV, 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.
UV, X-rays, and gamma rays are thus collectively called ionizing radiation; exposure to them can damage living tissue. UV can also cause substances to glow with visible light; this is called fluorescence. UV fluorescence is used by forensics to detect any evidence like blood and urine, that is produced by a crime scene.
The location of 'far-UVC' radiation (200-235 nm) in the electromagnetic spectrum. Far-UVC is a type of ultraviolet germicidal irradiation being studied and commercially developed for its combination of pathogen inactivation properties and reduced negative effects on human health when used within exposure guidelines. [1] [2] [3] [4]
Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. [1] Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz .
Electromagnetic radiation in this range of wavelengths is called visible light (or simply light). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well, known collectively as optical ...
Exposure to optical radiation can result in negative health effects. All wavelengths across this range of the spectrum, from UV to IR, can produce thermal injury to the surface layers of the skin, including the eye. When it comes from natural sources, this sort of thermal injury might be called a sunburn.
Ultraviolet astronomy is the observation of electromagnetic radiation at ultraviolet wavelengths between approximately 10 and 320 nanometres; shorter wavelengths—higher energy photons—are studied by X-ray astronomy and gamma-ray astronomy. [1] Ultraviolet light is not visible to the human eye. [2]
Prolonged exposure to ultraviolet radiation from the sun can lead to melanoma and other skin malignancies. [4] Clear evidence establishes ultraviolet radiation, especially the non-ionizing medium wave UVB, as the cause of most non-melanoma skin cancers, which are the most common forms of cancer in the world. [4]