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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 ...
Common Blue Violet (Viola sororia) color variant. Viola sororia is a short-stemmed, herbaceous perennial plant that grows in well-drained and shady habitats. [ 5 ] This 15–25 centimeters (6–10 in) wide violet has glossy, heart-shaped leaves and are topped with purple flowers with white throats. The lower three petals are hairy and the stem ...
Blue light, a type of high-energy light, is part of the visible light spectrum. High-energy visible light (HEV light) is short-wave light in the violet/blue band from 400 to 450 nm in the visible spectrum, which has a number of purported negative biological effects, namely on circadian rhythm and retinal health (blue-light hazard), which can lead to age-related macular degeneration.
Violet is the color of light at the short wavelength end of the visible spectrum. It is one of the seven colors that Isaac Newton labeled when dividing the spectrum of visible light in 1672. Violet light has a wavelength between approximately 380 and 435 nanometers. [2] The color's name is derived from the Viola genus of flowers. [3] [4]
Ultramarine is a deep blue color pigment which was originally made by grinding lapis lazuli into a powder. [2] Its lengthy grinding and washing process makes the natural pigment quite valuable—roughly ten times more expensive than the stone it comes from and as expensive as gold. [3][4] The name ultramarine comes from the Latin ultramarinus.
Diffuse sky radiation. In Earth's atmosphere, the dominant scattering efficiency of blue light is compared to red or green light. Scattering and absorption are major causes of the attenuation of sunlight radiation by the atmosphere. During broad daylight, the sky is blue due to Rayleigh scattering, while around sunrise or sunset, and especially ...
Silent Spring is an environmental science book by Rachel Carson. [1] Published on September 27, 1962, the book documented the environmental harm caused by the indiscriminate use of DDT, a pesticide used by soldiers during WW2. Carson accused the chemical industry of spreading disinformation, and public officials of accepting the industry's ...
Periwinkle is a color in the blue and violet family. Its name is derived from the lesser periwinkle or myrtle herb (Vinca minor) which bears flowers of the same color. The color periwinkle is also called lavender blue and light blue violet. [2] The color periwinkle may be considered a pale tint of purple-blue in the Munsell color system, or a ...