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Chappuis Bands
Chappuis absorption () refers to the absorption of electromagnetic radiation by ozone, which is especially noticeable in the ozone layer, which absorbs a small part of sunlight in the visible portion of the electromagnetic spectrum. The Chappuis absorption bands occur at wavelengths between 400 and 650 nm. Within this range are two absorption maxima of similar height at 575 and 603 nm. Compared to the absorption of ultraviolet light by the ozone layer, known as the Hartley and Huggins absorptions, Chappuis absorption is distinctly weaker. Along with Rayleigh scattering, it contributes to the blue color of the sky, and is noticeable when the light has to travel a long path through the Earth's atmosphere. For this reason, Chappuis absorption only has a significant effect on the color of the sky at dawn and dusk, during the so-called blue hour. It is named after the French chemist James Chappuis (1854–1934), who discovered this effect. History James Chappuis was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dawn
Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the appearance of indirect sunlight being scattered in Earth's atmosphere, when the centre of the Sun's disc has reached 18° below the observer's horizon. This morning twilight period will last until sunrise (when the Sun's upper limb breaks the horizon), when direct sunlight outshines the diffused light. Etymology "Dawn" derives from the Old English verb ''dagian'', "to become day". Types of dawn Dawn begins with the first sight of lightness in the morning, and continues until the Sun breaks the horizon. This morning twilight before sunrise is divided into three categories depending on the amount of sunlight that is present in the sky, which is determined by the angular distance of the centre of the Sun (degrees below the horizon) in the morning. These categories are ''astronomical'', ''nautical'', and ''civil dawn''. Astronomical dawn Astronomical dawn begins when the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Shadow
Earth's shadow (or Earth shadow) is the shadow that Earth itself casts through its atmosphere and into outer space, toward the antisolar point. During the twilight period (both early dusk and late dawn), the shadow's visible fringe – sometimes called the dark segment or twilight wedge – appears as a dark and diffuse band just above the horizon, most distinct when the sky is clear. Since Earth's diameter is 3.7 times the Moon's, the length of the planet's umbra is correspondingly 3.7 times that of the lunar umbra: roughly . Appearance Earth's shadow cast onto the atmosphere can be viewed during the "civil" stage of twilight, assuming the sky is clear and the horizon is relatively unobstructed. The shadow's fringe appears as a dark bluish to purplish band that stretches over 180° of the horizon opposite the Sun, i.e. in the eastern sky at dusk and in the western sky at dawn. Before sunrise, Earth's shadow appears to recede as the Sun rises; after sunset, the sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerosols
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be natural or Human impact on the environment, anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of anthropogenic aerosols include particulate air pollutants, mist from the discharge at Hydroelectric dam, hydroelectric dams, Irrigation, irrigation mist, Perfume, perfume from atomizers, smoke, steam from a kettle, Pesticide, sprayed pesticides, and medical treatments for respiratory illnesses. When a person inhales the contents of a vape pen or e-cigarette, they are inhaling an Human impact on the environment, anthropogenic aerosol. The liquid or solid particles in an aerosol have diameters typically less than micrometre, 1 μm (larger particles with a significant settling speed make the mixture a Suspension (chemistry), suspension, but the distinction is not clear-cut) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorbance
Absorbance is defined as "the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls)". Alternatively, for samples which scatter light, absorbance may be defined as "the negative logarithm of one minus absorptance, as measured on a uniform sample". The term is used in many technical areas to quantify the results of an experimental measurement. While the term has its origin in quantifying the absorption of light, it is often entangled with quantification of light which is “lost” to a detector system through other mechanisms. What these uses of the term tend to have in common is that they refer to a logarithm of the ratio of a quantity of light incident on a sample or material to that which is detected after the light has interacted with the sample. The term absorption refers to the physical process of absorbing light, while absorbance does not always measure only absorption; it may measure attenuation (of tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error
An error (from the Latin ''error'', meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake. The etymology derives from the Latin term 'errare', meaning 'to stray'. In statistics, "error" refers to the difference between the value which has been computed and the correct value. An error could result in failure or in a deviation from the intended performance or behavior. Human behavior One reference differentiates between "error" and "mistake" as follows: In human behavior the norms or expectations for behavior or its consequences can be derived from the intention of the actor or from the expectations of other individuals or from a social grouping or from social norms. (See deviance.) Gaffes and faux pas can be labels for certain instances of this kind of error. More serious departures from social norms carry labels such as misbehavior and labels from the legal system, such as misdemeanor and crime. Departures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Mexico
) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , OfficialLang = None , Languages = English language, English, Spanish language, Spanish (New Mexican Spanish, New Mexican), Navajo language, Navajo, Keres language, Keres, Zuni language, Zuni , Governor = , Lieutenant Governor = , Legislature = New Mexico Legislature , Upperhouse = New Mexico Senate, Senate , Lowerhouse = New Mexico House of Representatives, House of Representatives , Judiciary = New Mexico Supreme Court , Senators = * * , Representative = * * * , postal_code = NM , TradAbbreviation = N.M., N.Mex. , area_rank = 5th , area_total_sq_mi = 121,591 , area_total_km2 = 314,915 , area_land_sq_mi = 121,298 , area_land_km2 = 314,161 , area_water_sq_mi = 292 , area_water_km2 = 757 , area_water_percent = 0.24 , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Olson Hulburt
Edward Olson Hulburt (12 October 1890 – 11 October 1982) was an American geophysicist who studied the properties of the ionosphere and the color of the sky at the blue hour. Life and career Hulburt was born in Vermillion, South Dakota on 12 October 1890. He was educated at Johns Hopkins University, where his father was a professor of mathematics. He worked for 31 years at the United States Naval Research Laboratory, serving as head of the Physical Optics Division from 1929 to 1949, and Director of Research from 1949 to 1955. In 1926, he and Albert H. Taylor worked out several basic characteristics of the ionosphere, including the distribution of its electron density and dependence on solar elevation, by studying the propagation of radio signals in the atmosphere. They collaborated with Gregory Breit and Merle Tuve in the development of the ionosonde device used to study the ionosphere. Hulburt also studied how solar X-rays and extreme ultraviolet radiation were responsible f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarization (waves)
Polarization ( also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A simple example of a polarized transverse wave is vibrations traveling along a taut string ''(see image)''; for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic waves such as light and radio waves, gravitational waves, and transverse sound waves ( shear waves) in solids. An electromagneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auguste Houzeau
Auguste Houzeau (; 3 March 1829, Elbeuf – 17 February 1911, Rouen) was a French agronomist and chemist. He studied at the Conservatoire national des arts et métiers in Paris, where he took chemistry classes from Jean-Baptiste Boussingault. He later served as a professor at the École préparatoire à l'enseignement supérieur des sciences et des lettres in Rouen, and in 1883 was appointed director of the Station agronomique de la Seine-Inférieure. He was also president of the Société centrale d'agriculture de la Seine-Maritime.Prosopo Sociétés savantes de France He is remembered for his investigations on the nature of and its diffusion into the atmosphere; as well as for various studies of |
Princeton University Press
Princeton University Press is an independent Academic publishing, publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large. The press was founded by Whitney Darrow, with the financial support of Charles Scribner II, Charles Scribner, as a printing press to serve the Princeton community in 1905. Its distinctive building was constructed in 1911 on William Street in Princeton. Its first book was a new 1912 edition of John Witherspoon's ''Lectures on Moral Philosophy.'' History Princeton University Press was founded in 1905 by a recent Princeton graduate, Whitney Darrow, with financial support from another Princetonian, Charles Scribner II. Darrow and Scribner purchased the equipment and assumed the operations of two already existing local publishers, that of the ''Princeton Alumni Weekly'' and the Princeton Press. The new press printed both local newspapers, university documents, ''The Daily Princetonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Chappuis
Louis Philibert Claude James Chappuis (born 10 November 1854 in Besançon; died 29 January 1934 in Paris) was a French chemist and physicist. Life Chappuis was the son of philosophy teacher Charles Chappuis (1822–1897, lived from 1845 to 1869 in Besançon) and Louise Lydie Berthot (died 1909), a granddaughter of Nicolas Berthot, a mathematician in Dijon. He attended schools in Besançon, Caen and Grenoble. He enrolled in the École normale supérieure (ENS) in Paris in 1874, then worked as a physics teacher at Montauban in 1877, and at Poitiers in 1878. He returned to Paris and was a Maître de conférences at the ENS from 1878 to 1882, passing the Agrégé in 1879. In 1881, he was appointed as Professor of Physics at the École centrale des arts et manufactures, and attained the doctoral degree in 1882 with a thesis on the spectroscopy of ozone. He led the research laboratory of the ''Societé du Gaz de Paris''. Chappuis is interred in the family tomb in Chailly-sur-Arm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
