- published: 14 May 2016
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Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light. Although black is sometimes described as an "achromatic", or hueless, color, in practice it can be considered a color, as in expressions like "black cat" or "black paint".
The word black comes from Old English blæc ("black, dark", also, "ink"), from Proto-Germanic *blakkaz ("burned"), from Proto-Indo-European *bhleg- ("to burn, gleam, shine, flash"), from base *bhel- ("to shine"), related to Old Saxon blak ("ink"), Old High German blah ("black"), Old Norse blakkr ("dark"), Dutch blaken ("to burn"), and Swedish bläck ("ink"). More distant cognates include Latin flagrare ("to blaze, glow, burn"), and Ancient Greek phlegein ("to burn, scorch"). Black supplanted the wonted Old English word sweart ("black, dark"), which survives as swart, swarth, and swarthy (compare German schwarz and Dutch zwart, "black").
Black can be defined as the visual impression experienced when no visible light reaches the eye. (This makes a contrast with whiteness, the impression of any combination of colors of light that equally stimulates all three types of color-sensitive visual receptors.)
An umbrella or parasol (also called a brolly, parapluie, rainshade, sunshade, gamp, bumbershoot, or umbrolly) is a canopy designed to protect against rain or sunlight. The term parasol usually refers to an item designed to protect from the sun; umbrella refers to a device more suited to protect from rain. Often the difference is the material; some parasols are not waterproof. Parasols are often meant to be fixed to one point and often used with patio tables or other outdoor furniture. Umbrellas are almost exclusively hand-held portable devices; however, parasols can also be hand-held. The collapsible (or folding) umbrella originated from China, and had sliding levers similar to those in use of today.
The word umbrella comes from the Latin word umbra, meaning shade or shadow (the Latin word, in turn, derives from the Ancient Greek ómbros [όμβρος].) Brolly is a slang word for umbrella, used often in Britain, New Zealand, Australia, South Africa, and Kenya. Bumbershoot is a fanciful Americanism from the late 19th century.
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset thereof. It has been used for purposes of private recreation, non-commercial exchange of messages, experimentation, self-training, and emergency communication such as amateur (ham) radio and amateur television (ATV) in addition to commercial purposes like popular radio or TV stations with advertisements.
The term broadcast was first adopted by early radio engineers from the Midwestern United States, treating broadcast sowing as a metaphor for the dispersal inherent in omnidirectional radio signals.Broadcasting is a very large and significant segment[quantify] of the mass media.
Originally all broadcasting was composed of analog signals using analog transmission techniques and more recently broadcasters have switched to digital signals using digital transmission.
The world's technological capacity to receive information through one-way broadcast networks more than quadrupled during the two decades from 1986 to 2007, from 432 exabytes of (optimally compressed) information, to 1.9 zettabytes. This is the information equivalent of 55 newspapers per person per day in 1986, and 175 newspapers per person per day by 2007.