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A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave ultraviolet light and very little visible light. [ 1 ] [ 2 ] [ 3 ] One type of lamp has a violet filter material, either on the bulb or in a separate glass filter in the lamp housing, which blocks most visible light and allows through UV ...
Fluorescent light bulbs and tubes internally produce ultraviolet light. Normally this is converted to visible light by the phosphor film inside a protective coating. When the film is cracked by mishandling or faulty manufacturing then UV may escape at levels that could cause sunburn or even skin cancer. [53] [54]
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 kind ...
In 1974 Becky Schroeder was given a US patent for her invention of the "Glow Sheet" which used phosphorescent lines under writing paper to help people write in low-light conditions. [ 28 ] Glow in the dark material is added to the plastic blend used in injection molds to make some disc golf discs, which allow the game to be played at night.
Earth's land use for human agriculture in 2019. Earth has resources that have been exploited by humans. [263] Those termed non-renewable resources, such as fossil fuels, are only replenished over geological timescales. [264] Large deposits of fossil fuels are obtained from Earth's crust, consisting of coal, petroleum, and natural gas. [265]
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A black body or blackbody is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The radiation emitted by a black body in thermal equilibrium with its environment is called black-body radiation. The name "black body" is given because it absorbs all colors of light.
Said Palep, "At-home LED devices use lower frequencies, so [they] haven’t proven to be as effective or the results as dramatic as in-office treatments like the Blu-U light and micro pulsed Nd ...