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Shadow Band
Shadow bands are thin, wavy lines of alternating light and dark that can be seen moving and undulating in parallel on plain-coloured surfaces immediately before and after a total solar eclipse. They are caused by the refraction by Earth's atmospheric turbulence of the solar crescent as it thins to a narrow slit, which increasingly collimates the light reaching Earth in the minute just before and after totality. The shadows' detailed structure is due to random patterns of fine air turbulence that refract the collimated sunlight arriving from the narrow eclipse crescent. The bands' rapid sliding motion is due to shifting air currents combined with the angular motion of the Sun projecting through higher altitudes. The degree of collimation in the light gradually increases as the crescent thins, until the solar disk is completely covered and the eclipse is total. Stars twinkle for the same reason. All light passing through the Earth's atmosphere encounters tiny disturbances in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shadow Bands From Solar Eclipse 2017-08-21 Gamma 0
A shadow is a dark area on a surface where light from a light source is blocked by an object. In contrast, shade occupies the three-dimensional volume behind an object with light in front of it. The cross-section of a shadow is a two-dimensional silhouette, or a reverse projection of the object blocking the light. Point and non-point light sources A point source of light casts only a simple shadow, called an "umbra". For a non-point or "extended" source of light, the shadow is divided into the umbra, penumbra, and antumbra. The wider the light source, the more blurred the shadow becomes. If two penumbras overlap, the shadows appear to attract and merge. This is known as the shadow blister effect. The outlines of the shadow zones can be found by tracing the rays of light emitted by the outermost regions of the extended light source. The umbra region does not receive any direct light from any part of the light source and is the darkest. A viewer located in the umbra region cann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catherine Octavia Stevens
Catherine Octavia Stevens (1865-1959) was an amateur astronomer who was Director of the British Astronomical Association Meteor Section from 1905 to 1911. Her primary interest was the Sun and she made drawings of sunspots using a 3 inch refractor. She joined the six month old British Astronomical Association on 27 May 1891.Larsen, Kristine"Shooting Stars: The Women Directors of the Meteor Section of the British Astronomical Association" ''Antiquarian Astronomer'', 2006, Issue 3, pp 76-77 On the 1911 census she gave her occupation as Astronomer, working for the British Astronomical Association and her address was The Plain, Foxcombe Road, Oxford., a house with an observatory at the top of Boars Hill, Oxford. She lived there from 1910 to 1956. In 1939 she gave her occupation as Meteorologist Astronomer. Travels Catherine Stevens travelled to see total solar eclipses from Algiers on May 28, 1900, Majorca on August 30, 1905 and Quebec on August 31, 1932. She spent a year in She ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concan, Texas
Concan is a small unincorporated community in Uvalde County, Texas, United States. Description The community sits along the Frio River, close to Garner State Park and is a popular destination for summer vacationers. It is known for excellent birdwatching in the spring. A Roy Bechtol-designed 18-hole golf course called Concan Country Club or the Golf Club at Concan is open to the public. The area is dominated by large cattle, sheep and goat ranches some of which date back to when German emigrants settled this area. Several outfitters in the area haul swimmers and tubers up the Frio River to designated drop-off points, then pick them up downstream. The name "Concan" may have originated from the card game Conquian.John Leffler, "CONCAN, TX," Handbook of Texas Onlin Published by the Texas State Historical Association The Texas State Historical Association (TSHA) is an American nonprofit educational and research organization dedicated to documenting the history of Tex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barometric Pressure
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.25 millibars, 760 mm Hg, 29.9212 inchesHg, or 14.696 psi.International Civil Aviation Organization. ''Manual of the ICAO Standard Atmosphere'', Doc 7488-CD, Third Edition, 1993. . The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm. In most circumstances, atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. As elevation increases, there is less overlying atmospheric mass, so atmospheric pressure decreases with increasing elevation. Because the atmosphere is thin relative to the Earth's radius—especially the dense atmospheric layer at low altitudes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-altitude Balloon
High-altitude balloons or stratostats are usually uncrewed balloons typically filled with helium or hydrogen and released into the stratosphere, generally attaining between above sea level. In 2013, a balloon named BS 13-08 reached a record altitude of . The most common type of high-altitude balloons are weather balloons. Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters, cameras, or satellite navigation systems, such as GPS receivers. Hobbyists frequently purchase weather balloons because of their ease of use, low price point, and widespread commoditisation. These balloons are launched into what is defined as "near space", defined as the area of Earth's atmosphere between the Armstrong limit ( above sea level), where pressure falls to the point that a human being cannot survive without a pressurised suit, and the Kármán line ( above sea level), where astrodynamics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Pittsburgh
The University of Pittsburgh (Pitt) is a Commonwealth System of Higher Education, state-related research university in Pittsburgh, Pennsylvania, United States. The university is composed of seventeen undergraduate and graduate schools and colleges at its Urban university, urban Pittsburgh campus, home to the university's central administration and around 28,000 undergraduate and graduate students. The 132-acre Pittsburgh campus includes various historic buildings that are part of the Schenley Farms Historic District, most notably its 42-story Gothic Revival architecture, Gothic revival centerpiece, the Cathedral of Learning. Pitt is a member of the Association of American Universities and is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Pitt traces its roots to the Pittsburgh Academy founded by Hugh Henry Brackenridge in 1787. While the city was still on the History of Pittsburgh#Gatewa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC News
BBC News is an operational business division of the British Broadcasting Corporation (BBC) responsible for the gathering and broadcasting of news and current affairs in the UK and around the world. The department is the world's largest broadcast news organisation and generates about 120 hours of radio and television output each day, as well as online news coverage. The service has over 5,500 journalists working across its output including in 50 foreign news bureaus where more than 250 foreign correspondents are stationed. Deborah Turness has been the CEO of news and current affairs since September 2022. In 2019, it was reported in an Ofcom report that the BBC spent £136m on news during the period April 2018 to March 2019. BBC News' domestic, global and online news divisions are housed within the largest live newsroom in Europe, in Broadcasting House in central London. Parliamentary coverage is produced and broadcast from studios in London. Through BBC English Regions, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrasound
Infrasound, sometimes referred to as low frequency sound or incorrectly subsonic (subsonic being a descriptor for "less than the speed of sound"), describes sound waves with a Audio frequency, frequency below the lower limit of human audibility (generally 20 Hertz, Hz, as defined by the ANSI/ASA S1.1-2013 standard). Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. Although the ear is the primary organ for sensing low sound, at higher intensities it is possible to feel infrasound vibrations in various parts of the body. The study of such sound waves is sometimes referred to as infrasonics, covering sounds beneath 20 Hz down to 0.1 Hz (and rarely to 0.001 Hz). People use this frequency range for monitoring earthquakes and volcanoes, charting rock and petroleum formations below the earth, and also in ballistocardiography and seismocardiography to study the mechanics of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal in astronomy, astrophysics and related fields. It publishes original research in two formats: papers (of any length) and letters (limited to five pages). MNRAS publishes more articles per year than any other astronomy journal. The learned society journal has been in continuous existence since 1827 and became online only in 2020. It operates as a partnership between the Royal Astronomical Society (RAS), who select and peer-review the contents, and Oxford University Press (OUP), who publish and market the journal. Despite its name, MNRAS is no longer monthly, nor does it carry the notices of the RAS. In 2024 MNRAS became a purely gold open access journal. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zaragoza
Zaragoza (), traditionally known in English as Saragossa ( ), is the capital city of the province of Zaragoza and of the autonomous communities of Spain, autonomous community of Aragon, Spain. It lies by the Ebro river and its tributaries, the Huerva and the Gállego (river), Gállego, roughly in the centre of both Aragon and the Ebro basin. On 1 January 2021, the population of the municipality of Zaragoza was 675,301, (as of 2023, the Ranked lists of Spanish municipalities#By population, fourth or fifth most populous in Spain) on a land area of . It is the list of cities in the European Union by population within city limits, 26th most populous municipality in the European Union. The population of the metropolitan area was estimated in 2006 at 783,763 inhabitants. The municipalities of Spain, municipality is home to more than 50 percent of the Aragonese population. The city lies at an elevation of about height above mean sea level, above sea level. Zaragoza hosted Expo 2008 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majorca
Mallorca, or Majorca, is the largest of the Balearic Islands, which are part of Spain, and the List of islands in the Mediterranean#By area, seventh largest island in the Mediterranean Sea. The capital of the island, Palma, Majorca, Palma, is also the capital of the autonomous communities of Spain, autonomous community of the Balearic Islands. The Balearic Islands have been an autonomous region of Spain since 1983. There are two small islands off the coast of Mallorca: Cabrera, Balearic Islands, Cabrera (southeast of Palma) and Dragonera (west of Palma). The anthem of Mallorca is "La Balanguera". Like the other Balearic Islands of Menorca, Ibiza, and Formentera, the island is a highly popular holiday destination, particularly for tourists from the Netherlands, Republic of Ireland, Ireland, Germany, and the United Kingdom. The international airport, Palma de Mallorca Airport, is one of the busiest in Spain; it was used by 28 million passengers in 2017, with use increasing ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse Of July 8, 1842
A total solar eclipse occurred at the Moon's descending node of orbit on Friday, July 8, 1842, with a magnitude of 1.0543. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 2 days before perigee (on July 10, 1842, at 7:50 UTC), the Moon's apparent diameter was larger. The path of totality was visible from parts of modern-day Portugal, Spain, Andorra, France, Monaco, Italy, Austria, Slovenia, Hungary, Slovakia, southeastern Poland, Ukraine, southeastern Belarus, Russia, Kazakhstan, Mongolia, China, the Ryukyu Islands, and the Northern Mariana Islands. A partial solar eclipse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
