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Lighthouse Of Osmussaar
__NOTOC__ Osmussaar Lighthouse ( et, Osmussaare tuletorn) is a lighthouse on the northwestern peak of Osmussaar. The lighthouse was built in 1954, is made of reinforced concrete and is 35 meters tall. History The first stone beacon on Osmussaar was built in 1765. In 1804 it was elevated and equipped with a lantern room containing a catoptric lighting device with 24 lamps and reflectors. In 1814 the lighthouse collapsed and was replaced by a temporary wooden tower. In 1850 a new stone lighthouse was built and equipped with a dioptric Fresnel lighting device in 1875. In 1902 the lighthouse became powered by electricity. The lighthouse was blown up by the Soviet soldiers before evacuation in 1941. The current lighthouse was built in 1954 to replace the temporary wooden structure which was erected after the war. See also * List of lighthouses in Estonia This is a list of lighthouses in Estonia. Lighthouses See also * Lists of lighthouses References Externa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmussaar
Osmussaar ( sv, Odensholm, german: Odinsholm) is an Estonian island situated in the mouth of the Gulf of Finland in the Baltic Sea, 7.5 km off the Estonian mainland. Administratively the island is part of Lääne-Nigula Parish in Lääne County. Its area is . Before the Soviet Union occupied Estonia during World War II, around 130 people, mainly Estonian Swedes, lived on the island. The continuous settlement of Swedes on Osmussaar had dated back for centuries. Currently Osmussaar has only two permanent inhabitants and the island is a nature reserve. Name The island's Swedish name ''Odensholm'' (or ''Odinsholm'') derives from the Vikings' chief god, Odin, who, according to a legend, is buried on the island. The origin of the Estonian name ''Osmussaar'' is not clear. History The continuous settlement of Estonian Swedes on Osmussaar, which lasted until World War II, goes back at least to the 14th century, though little is known of the island's history before the 18th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioptric
Dioptrics is the branch of optics dealing with refraction, similarly the branch dealing with mirrors is known as catoptrics. Dioptrics is the study of the refraction of light, especially by lenses. Telescopes that create their image with an objective that is a convex lens ( refractors) are said to be "dioptric" telescopes. An early study of dioptrics was conducted by Ptolemy in relationship to the human eye as well as refraction in media such as water. The understanding of the principles of dioptrics was further expanded by Alhazen, considered the father of modern optics. See also * Diopter/Dioptre (unit of measurement) * Dioptrice (work by Johannes Kepler) * Catoptrics (study of and optical systems utilizing reflection) * Catadioptrics (study of and optical systems utilizing reflection and refraction) * Optical telescope * List of telescope types * Image-forming optical system In optics, an image-forming optical system is a system capable of being used for imaging. The diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses In Estonia
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and has become uneconomical since the advent of much cheaper, more sophisticated and effective electronic navigational systems. History Ancient lighthouses Before the development of clearly defined ports, mariners were guided by fires built on hilltops. Since elevating the fire would improve the visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for ree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lääne-Nigula Parish
Lääne-Nigula Parish ( et, Lääne-Nigula vald) is a rural municipality of Estonia, in Lääne County. It has a population of 7,041 (as of 1 January 2019) and an area of . Lääne-Nigula Parish was established by merging Oru, Risti and Taebla parishes after the municipal elections held on 20 October 2013. In 2017, the former municipalities Noarootsi, Nõva, Kullamaa and Martna were also merged into Lääne-Nigula. Politics There are 17 seats in the local government council. Settlements ;Small boroughs: Palivere - Taebla - Risti ;Villages: Allikmaa - Allikotsa - Auaste - Aulepa - Dirhami - Ehmja - Einbi - Elbiku - Enivere - Hara - Hindaste - Hosby - Höbringi - Ingküla - Jaakna - Jalukse - Jõesse - Jõgisoo - Kaare - Kaasiku - Kabeli - Kadarpiku - Kalju - Kärbla - Kasari - Kastja - Kedre - Keedika - Keravere - Keskküla - Keskvere - Kesu - Kirimäe - Kirna - Koela - Kokre - Koluvere - Kudani - Kuijõe - Kuke - Kullamaa - Kullametsa - Ku ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Lighthouses In Estonia ...
This is a list of lighthouses in Estonia. Lighthouses See also * Lists of lighthouses References External links * {{Lighthouses in Europe Estonia * Lighthouses Lighthouses A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways. Lighthouses mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soviet
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national republics; in practice, both its government and its economy were highly centralized until its final years. It was a one-party state governed by the Communist Party of the Soviet Union, with the city of Moscow serving as its capital as well as that of its largest and most populous republic: the Russian SFSR. Other major cities included Leningrad (Russian SFSR), Kiev (Ukrainian SSR), Minsk (Byelorussian SSR), Tashkent (Uzbek SSR), Alma-Ata (Kazakh SSR), and Novosibirsk (Russian SFSR). It was the largest country in the world, covering over and spanning eleven time zones. The country's roots lay in the October Revolution of 1917, when the Bolsheviks, under the leadership of Vladimir Lenin, overthrew the Russian Provisional Government that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel
Augustin-Jean Fresnel (10 May 1788 – 14 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, excluding any remnant of Newton's corpuscular theory, from the late 1830s until the end of the 19th century. He is perhaps better known for inventing the catadioptric (reflective/refractive) Fresnel lens and for pioneering the use of "stepped" lenses to extend the visibility of lighthouses, saving countless lives at sea. The simpler dioptric (purely refractive) stepped lens, first proposed by Count Buffon and independently reinvented by Fresnel, is used in screen magnifiers and in condenser lenses for overhead projectors. By expressing Huygens's principle of secondary waves and Young's principle of interference in quantitative terms, and supposing that simple colors consist of sinusoidal waves, Fresnel gave the first satisfactory explanation of diffraction by straight edges, includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catoptric
Catoptrics (from grc-gre, κατοπτρικός ''katoptrikós'', "specular", from grc-gre, κάτοπτρον ''katoptron'' "mirror") deals with the phenomena of reflected light and image-forming optical systems using mirrors. A catoptric system is also called a ''catopter'' (''catoptre''). Ancient texts ''Catoptrics'' is the title of two texts from ancient Greece: *The Pseudo-Euclidean ''Catoptrics''. This book is attributed to Euclid, although the contents are a mixture of work dating from Euclid's time together with work which dates to the Roman period., accessed 31 January 2013 It has been argued that the book may have been compiled by the 4th century mathematician Theon of Alexandria. The book covers the mathematical theory of mirrors, particularly the images formed by plane and spherical concave mirrors. *Hero's ''Catoptrics''. Written by Hero of Alexandria, this work concerns the practical application of mirrors for visual effects. In the Middle Ages, this work was fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estonia
Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, and to the east by Lake Peipus and Russia. The territory of Estonia consists of the mainland, the larger islands of Saaremaa and Hiiumaa, and over 2,200 other islands and islets on the eastern coast of the Baltic Sea, covering a total area of . The capital city Tallinn and Tartu are the two largest urban areas of the country. The Estonian language is the autochthonous and the official language of Estonia; it is the first language of the majority of its population, as well as the world's second most spoken Finnic language. The land of what is now modern Estonia has been inhabited by '' Homo sapiens'' since at least 9,000 BC. The medieval indigenous population of Estonia was one of the last "pagan" civilisations in Europe to adop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beacon
A beacon is an intentionally conspicuous device designed to attract attention to a specific location. A common example is the lighthouse, which draws attention to a fixed point that can be used to navigate around obstacles or into port. More modern examples include a variety of radio beacons that can be read on radio direction finders in all weather, and radar transponders that appear on radar displays. Beacons can also be combined with semaphoric or other indicators to provide important information, such as the status of an airport, by the colour and rotational pattern of its airport beacon, or of pending weather as indicated on a weather beacon mounted at the top of a tall building or similar site. When used in such fashion, beacons can be considered a form of optical telegraphy. For navigation Beacons help guide navigators to their destinations. Types of navigational beacons include radar reflectors, radio beacons, sonic and visual signals. Visual beacons range from smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinforced Concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion. Description Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
