Ultraviolet (UV) is a form of electromagnetic radiation with wavelength shorter than that of visible light, but longer than X-rays. (wikipedia.org)
Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. (wikipedia.org)
UV radiation was discovered in 1801 when the German physicist Johann Wilhelm Ritter observed that invisible rays just beyond the violet end of the visible spectrum darkened silver chloride-soaked paper more quickly than violet light itself. (wikipedia.org)
The terms "chemical rays" and "heat rays" were eventually dropped in favor of ultraviolet and infrared radiation, respectively. (wikipedia.org)
In 1960, the effect of ultraviolet radiation on DNA was established. (wikipedia.org)
The discovery of the ultraviolet radiation with wavelengths below 200 nm, named "vacuum ultraviolet" because it is strongly absorbed by the oxygen in air, was made in 1893 by German physicist Victor Schumann. (wikipedia.org)
The electromagnetic spectrum of ultraviolet radiation (UVR), defined most broadly as 10-400 nanometers, can be subdivided into a number of ranges recommended by the ISO standard ISO 21348: Several solid-state and vacuum devices have been explored for use in different parts of the UV spectrum. (wikipedia.org)
Long-term overexposure th ultraviolet radiation is hazardous to eyes and skin and may produced erythema, photokeratitis (snow blindness), and/or skin cancer. (mfa.org)
Chalking occurs due to ultra violet (UV) radiation from sunlight interacting with the constituents within the paint film. (dulux.com.au)
Darker colours absorb more energy (heat and UV radiation) from sunlight than lighter colours thereby putting greater stress on paint coating. (dulux.com.au)
Solar3
solar%20radiation sunlight] and is also generated by almost all types of electrical light sources. (mfa.org)
These observations are the first to reveal the rich variability in the solar "sunlight" ultra violet spectrum. (usu.edu)
The research is to understand in depth the response of the ionosphere to the solar variability in the ultra-violet spectrum. (usu.edu)
Occurs1
Chalking occurs more quickly in exterior environments where the painted surface is fully exposed to high levels of sunlight over an extended period. (dulux.com.au)
Light7
citation needed] Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. (wikipedia.org)
However, ultraviolet light (specifically, UVB) is also responsible for the formation of vitamin D in most land vertebrates, including humans. (wikipedia.org)
The lower wavelength limit of human vision is conventionally taken as 400 nm, so ultraviolet rays are invisible to humans, although people can sometimes perceive light at shorter wavelengths than this. (wikipedia.org)
Ultraviolet" means "beyond violet" (from Latin ultra, "beyond"), violet being the color of the highest frequencies of visible light. (wikipedia.org)
Ultraviolet has a higher frequency (thus a shorter wavelength) than violet light. (wikipedia.org)
In that respect, the most important issues are the colour green and ultra violet light within full spectrum sunlight. (positivehealth.com)
This also explains our disconnection from nature from the philosophical perspective of spiritual healing, and how a lack of green and ultra violet light can cause a dis-ease within ourselves, and adversely affect our relationships with others. (positivehealth.com)
Fluorescent light1
Sunlight, fluorescent light and incandescent light all produce some light in the violet and ultraviolet range. (sciencedaily.com)
Nevertheless, the photoreceptors of the retina are sensitive to near-UV, and people lacking a lens (a condition known as aphakia) perceive near-UV as whitish-blue or whitish-violet. (wikipedia.org)