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Dark Thick-thumbed Bat
Darkness, the direct opposite of lightness, is defined as a lack of illumination, an absence of visible light, or a surface that absorbs light, such as black or brown. Human vision is unable to distinguish colors in conditions of very low luminance. This is because the hue sensitive photoreceptor cells on the retina are inactive when light levels are insufficient, in the range of visual perception referred to as scotopic vision. The emotional response to darkness has generated metaphorical usages of the term in many cultures, often used to describe an unhappy or foreboding feeling. Referring to a time of day, complete darkness occurs when the Sun is more than 18° below the horizon, without the effects of twilight on the night sky. Scientific Perception The perception of darkness differs from the mere absence of light due to the effects of after images on perception. In perceiving, the eye is active, and the part of the retina that is unstimulated produces a complementary ...
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Creation Of Light
Creation may refer to: Religion *''Creatio ex nihilo'', the concept that matter was created by God out of nothing * Creation myth, a religious story of the origin of the world and how people first came to inhabit it * Creationism, the belief that the universe was created in specific divine acts and the social movement affiliated with it *Creator deity, a deity responsible for the creation of everything that exists * Genesis creation narrative, the biblical account of creation *Creation Museum, a creationist museum in Kentucky *Creation Ministries International, a Christian apologetics organization *Creation Festival, two annual four-day Christian music festivals held in the United States Entertainment Music Albums * ''Creation'' (EP), 2016 EP by Seven Lions * ''Creation'' (John Coltrane album), 1965 * ''Creation'' (Branford Marsalis album), 2001 * ''Creation'' (Keith Jarrett album), 2015 * ''Creation'' (Archie Roach album), 2013 * ''Creation'' (The Pierces album), 2014 *''Creatio ...
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Photons
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always move at the speed of light in vacuum, (or about ). The photon belongs to the class of bosons. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the photoelectric effect, Ein ...
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Composition (visual Arts)
The term composition means "putting together". It can be thought of as the organization of the elements of art according to the principles of art. Composition can apply to any work of art, from music through writing and into photography, that is arranged using conscious thought. In the visual arts, composition is often used interchangeably with various terms such as ''design, form, visual ordering,'' or ''formal structure,'' depending on the context. In graphic design for press and desktop publishing, composition is commonly referred to as page layout. The composition of a picture is different from its subject (what is depicted), whether a moment from a story, a person or a place. Many subjects, for example Saint George and the Dragon, are often portrayed in art, but using a great range of compositions even though the two figures are typically the only ones shown. Elements of design The central visual element, known as ''element of design'', ''formal element'', or ''elemen ...
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The Calling Of Saint Matthew-Caravaggo (1599-1600)
''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with pronouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of pronoun ''thee'') when followed by a v ...
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Computer Display
A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls. The display in modern monitors is typically an LCD with LED backlight, having by the 2010s replaced CCFL backlit LCDs. Before the mid- 2000s, most monitors used a CRT. Monitors are connected to the computer via DisplayPort, HDMI, USB-C, DVI, VGA, or other proprietary connectors and signals. Originally, computer monitors were used for data processing while television sets were used for video. From the 1980s onward, computers (and their monitors) have been used for both data processing and video, while televisions have implemented some computer functionality. In the 2000s, the typical display aspect ratio of both televisions and computer monitors has changed from 4:3 to 16:9. Modern computer monitors are mostly interchangeable with televisi ...
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Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a sample of an original image; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''sensel'' is sometimes used), while in yet other contexts (like MRI) it may refer to a set of component intensities for a spatial position. Etymology The w ...
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Guinness World Records
''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world records both of human achievements and the extremes of the natural world. The brainchild of Sir Hugh Beaver, the book was co-founded by twin brothers Norris and Ross McWhirter in Fleet Street, London, in August 1955. The first edition topped the best-seller list in the United Kingdom by Christmas 1955. The following year the book was launched internationally, and as of the 2022 edition, it is now in its 67th year of publication, published in 100 countries and 23 languages, and maintains over 53,000 records in its database. The international franchise has extended beyond print to include television series and museums. The popularity of the franchise has resulted in ''Guinness World Records'' becoming the primary international authority ...
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Vantablack
Vantablack is a brand name for a class of super-black coatings with total hemispherical reflectances (THR) below 1.5% in the visible spectrum. The coatings were invented by Ben Jensen, who first publicly unveiled them in July 2014, and commercialised by the scientific team from Surrey NanoSystems. The original Vantablack coating was grown from a chemical vapour deposition process (CVD) and is claimed to be the "world's darkest material", absorbing up to 99.965% of visible light perpendicular to the material at 663 nm. The coatings are unique in that they are not only super-black but that they retain uniform light absorption from almost all viewing angles. Original CVD Vantablack is no longer manufactured for commercial applications as it has been superseded by Vantablack spray coatings that offer similar optical performance in key parts of the electromagnetic spectrum. The name is a combination of the acronym ''VANTA'' ( vertically aligned nanotube arrays) and the color ''b ...
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Sky Brightness
Sky brightness refers to the visual perception of the sky and how it scatters and diffuses light. The fact that the sky is not completely dark at night is easily visible. If light sources (e.g. the Moon and light pollution) were removed from the night sky, only direct starlight would be visible. The sky's brightness varies greatly over the day, and the primary cause differs as well. During daytime, when the Sun is above the horizon, the direct scattering of sunlight is the overwhelmingly dominant source of light. During twilight (the duration after sunset or before sunrise until or since, respectively, the full darkness of night), the situation is more complicated, and a further differentiation is required. Twilight (both dusk and dawn) is divided into three 6° segments that mark the Sun's position below the horizon. At civil twilight, the center of the Sun's disk appears to be between 1/4° and 6° below the horizon. At nautical twilight, the Sun's altitude is between †...
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Bortle Dark-Sky Scale
The Bortle scale (also known as the Bottle scale) is a nine-level numeric scale that measures the night sky's brightness of a particular location. It quantifies the astronomical observability of celestial objects and the interference caused by light pollution. John E. Bortle created the scale and published it in the February 2001 edition of ''Sky & Telescope'' magazine to help amateur astronomers evaluate the darkness of an observing site, and secondarily, to compare the darkness of observing sites. The scale ranges from Class 1, the darkest skies available on Earth, through to Class 9, inner-city skies. It gives several criteria for each level beyond naked-eye limiting magnitude (NELM). The accuracy and utility of the scale have been questioned in recent research. The table below summarizes Bortle's descriptions of the classes. Some classes can have very drastic differences from the one next to it, e.g, Bortle 4 to 5. In popular culture The band Days N' Daze referenced the scale ...
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Rhodopsin
Rhodopsin, also known as visual purple, is a protein encoded by the RHO gene and a G-protein-coupled receptor (GPCR). It is the opsin of the rod cells in the retina and a light-sensitive receptor protein that triggers visual phototransduction in rods. Rhodopsin mediates dim light vision and thus is extremely sensitive to light. When rhodopsin is exposed to light, it immediately photobleaches. In humans, it is regenerated fully in about 30 minutes, after which the rods are more sensitive. Defects in the rhodopsin gene cause eye diseases such as retinitis pigmentosa and congenital stationary night blindness. Names Rhodopsin was discovered by Franz Christian Boll in 1876. The name rhodospsin derives from Ancient Greek () for "rose", due to its pinkish color, and () for "sight". It was coined in 1878 by the German physiologist Wilhelm Friedrich Kühne (1837-1900). When George Wald discovered that rhodopsin is a holoprotein, consisting of retinal and an apoprotein, he c ...
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Rods And Cones
A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential. There are currently three known types of photoreceptor cells in mammalian eyes: rods, cones, and intrinsically photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form an image of the environment, sight. Rods primarily mediate scotopic vision (dim conditions) whereas cones primarily mediate to photopic vision (bright conditions), but the processes in each that supports phototransduction is similar. A third class of mammalian photoreceptor cell was discovere ...
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