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Green Flash
The green flash and green ray are meteorological optical phenomena that sometimes occur transiently around the moment of sunset or sunrise. When the conditions are right, a distinct green spot is briefly visible above the Sun's upper limb; the green appearance usually lasts for no more than two seconds. Rarely, the green flash can resemble a green ray shooting up from the sunset or sunrise point. Green flashes occur because the Earth's atmosphere can cause the light from the Sun to separate, via wavelength varying refraction, into different colors. Green flashes are a group of similar phenomena that stem from slightly different causes, and therefore, some types of green flashes are more common than others. Observing Green flashes may be observed from any altitude. They usually are seen at an unobstructed horizon, such as over the ocean, but are possible over cloud tops and mountain tops as well. They may occur at any latitude, although at the equator, the flash rarely l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Development Of Green Flash
Development or developing may refer to: Arts *Development (music), the process by which thematic material is reshaped *Photographic development *Filmmaking#Development, Filmmaking, development phase, including finance and budgeting *Development hell, when a project is stuck in development *Development (band), English progressive pop rock band *Development (album), ''Development'' (album), a 2002 album by Nonpoint Business *Business development, a process of growing a business *Career development *Corporate development, a position in a business *Energy development, activities concentrated on obtaining energy from natural resources *Green development, a real estate concept that considers social and environmental impact of development *Land development, altering the landscape in any number of ways *Land development bank, a kind of bank in India *Leadership development *New product development *Organization development *Professional development *Real estate development *Research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vatican Observatory
The Vatican Observatory () is an astronomical research and educational institution supported by the Holy See. Originally based in the Roman College of Rome, the Observatory is now headquartered in Castel Gandolfo, Italy and operates a telescope at the Mount Graham International Observatory in the United States. The Director of the Observatory is Brother Guy Consolmagno, an American Jesuit. In 2008, the Templeton Prize was awarded to cosmologist Fr. Michał Heller, a Vatican Observatory Adjunct Scholar. In 2010, the George Van Biesbroeck Prize was awarded to former observatory director, the American Jesuit, Fr. George Coyne. History The Church has had a long-standing interest in astronomy, due to the astronomical basis of the calendar by which holy days and Easter are determined. For instance, the Gregorian Calendar, promulgated in 1582 by Pope Gregory XIII, was developed by Aloysius Lilius and later modified by Christoph Clavius at the Collegio Romano from astronomical dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Rim Of The Setting Sun
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in the RGB color model, used on television and computer screens, it is one of the additive primary colors, along with red and blue, which are mixed in different combinations to create all other colors. By far the largest contributor to green in nature is chlorophyll, the chemical by which plants photosynthesize and convert sunlight into chemical energy. Many creatures have adapted to their green environments by taking on a green hue themselves as camouflage. Several minerals have a green color, including the emerald, which is colored green by its chromium content. During post-classical and early modern Europe, green was the color commonly associated with wealth, merchants, bankers, and the gentry, while red was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumulus Cloud
Cumulus clouds are clouds that have flat cloud base, bases and are often described as puffy, cotton-like, or fluffy in appearance. Their name derives from the Latin , meaning "heap" or "pile". Cumulus clouds are low-level clouds, generally less than in altitude unless they are the more vertical cumulus congestus form. Cumulus clouds may appear by themselves, in lines, or in clusters. Cumulus clouds are often precursors of other types of clouds, such as cumulonimbus cloud, cumulonimbus, when influenced by weather factors such as atmospheric instability, instability, humidity, and temperature gradient. Normally, cumulus clouds produce little or no precipitation, but they can grow into the precipitation-bearing cumulus congestus or cumulonimbus clouds. Cumulus clouds can be formed from water vapour, supercooling, supercooled water droplets, or ice crystals, depending upon the ambient temperature. They come in many distinct subforms and generally cool the earth by reflecting the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inversion (meteorology)
In meteorology, an inversion (or temperature inversion) is a phenomenon in which a layer of warmer air overlies cooler air. Normally, atmospheric temperature, air temperature gradually decreases as altitude increases, but this relationship is reversed in an inversion. An inversion traps air pollution, such as smog, near the ground. An inversion can also suppress atmospheric convection, convection by acting as a "cap". If this cap is broken for any of several reasons, convection of any humidity can then erupt into violent thunderstorms. Temperature inversion can cause freezing rain in polar climate, cold climates. Normal atmospheric conditions Usually, within the lower atmosphere (the troposphere) the air near the surface of the Earth is warmer than the air above it, largely because the atmosphere is heated from below as solar radiation warms the Earth's surface, which in turn then warms the layer of the atmosphere directly above it, e.g., by thermals (Convection (heat tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hourglass
An hourglass (or sandglass, sand timer, or sand clock) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the upper bulb to the lower one due to gravity. Typically, the upper and lower bulbs are symmetric as they are usually manufactured by pinching a tube. The specific duration of time a given hourglass measures is determined by factors including the quantity and coarseness of the particulate matter and the neck width. Depictions of an hourglass as a symbol of the passage of time are found in art, especially on tombstones or other monuments, from antiquity to the present day. The form of a winged hourglass has been used as a literal depiction of the Latin phrase ("time flies"). History Antiquity The origin of the hourglass is unclear. Its predecessor the ''clepsydra'', or water clock, is known to have existed in Babylon and Egypt as early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Duct
In telecommunications, an atmospheric duct is a horizontal layer in the lower atmosphere in which the vertical refractive index gradients are such that radio signals (and light rays) are guided or ducted, tend to follow the curvature of the Earth, and experience less attenuation in the ducts than they would if the ducts were not present. The duct acts as an atmospheric dielectric waveguide and limits the spread of the wavefront to only the horizontal dimension. Atmospheric ducting is a mode of propagation of electromagnetic radiation, usually in the lower layers of Earth’s atmosphere, where the waves are bent by atmospheric refraction. In over-the-horizon radar, ducting causes part of the radiated and target-reflection energy of a radar system to be guided over distances far greater than the normal radar range. It also causes long-distance propagation of radio signals in bands that would normally be limited to line of sight. Normally radio "ground waves" propagate along the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washington University School Of Medicine
Washington University School of Medicine (WashU Medicine) is the medical school of Washington University in St. Louis, located in the Central West End neighborhood of St. Louis, Missouri. Founded in 1891, the School of Medicine shares a campus with Barnes-Jewish Hospital, St. Louis Children's Hospital, and the Alvin J. Siteman Cancer Center. The clinical service is provided by Washington University Physicians, a comprehensive medical and surgical practice providing treatment in more than 75 medical specialties. Washington University Physicians are the medical staff of the school's two teaching hospitals – Barnes-Jewish Hospital and St. Louis Children's Hospital. They also provide inpatient and outpatient care at the St. Louis Veteran's Administration Hospital, hospitals of the BJC HealthCare system, and 35 other office locations throughout the greater St. Louis region. History Medical classes were first held at Washington University in 1891 after the St. Louis Medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnification
Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a size ratio called optical magnification. When this number is less than one, it refers to a reduction in size, sometimes called ''de-magnification''. Typically, magnification is related to scaling up visuals or images to be able to see more detail, increasing resolution, using microscope, printing techniques, or digital processing. In all cases, the magnification of the image does not change the perspective of the image. Examples of magnification Some optical instruments provide visual aid by magnifying small or distant subjects. * A magnifying glass, which uses a positive (convex) lens to make things look bigger by allowing the user to hold them closer to their eye. * A telescope, which uses its large objective lens or primary mirror to create an image of a distant object and then allows the user to examine the image closely with a smaller ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayleigh Scattering
Rayleigh scattering ( ) is the scattering or deflection of light, or other electromagnetic radiation, by particles with a size much smaller than the wavelength of the radiation. For light frequencies well below the resonance frequency of the scattering medium (normal dispersion relation, dispersion regime), the amount of scattering is inversely proportional to the fourth power of the wavelength (e.g., a blue color is scattered much more than a red color as light propagates through air). The phenomenon is named after the 19th-century British physicist Lord Rayleigh (John William Strutt). Rayleigh scattering results from the electric polarizability of the particles. The oscillating electric field of a light wave acts on the charges within a particle, causing them to move at the same frequency. The particle, therefore, becomes a small radiating dipole whose radiation we see as scattered light. The particles may be individual atoms or molecules; it can occur when light travels throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirage Of Astronomical Objects
A mirage of an astronomical object is a meteorological optical phenomenon, in which light rays are bent to produce distorted or multiple images of an astronomical object. The mirages might be observed for such celestial objects as the Sun, the Moon, the planets, bright stars, and very bright comets. The most commonly observed of these are sunset and sunrise mirages. Mirages versus refraction Mirages are distinguished from other phenomena caused by atmospheric refraction. One of the most prominent features of mirages is that a mirage might only produce images vertically, not sideways, while a simple refraction might distort and bend the images in any way. The distortion in both images displayed in this section was caused by refraction, but while the image on the left, which is a mirage, demonstrates only vertical distortion, the image on the right demonstrates distortion in all the ways possible. It is easier to see the vertical direction of the mirage not even at the mirage o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
