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Underwater Sound
Underwater acoustics is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water, its contents and its boundaries. The water may be in the ocean, a lake, a river or a tank. Typical frequencies associated with underwater acoustics are between 10 Hz and 1 MHz. The propagation of sound in the ocean at frequencies lower than 10 Hz is usually not possible without penetrating deep into the seabed, whereas frequencies above 1 MHz are rarely used because they are absorbed very quickly. Underwater acoustics is sometimes known as hydroacoustics. The field of underwater acoustics is closely related to a number of other fields of acoustic study, including sonar, transduction, signal processing, acoustical oceanography, bioacoustics, and physical acoustics. History Underwater sound has probably been used by marine animals for millions of years. The science of underwater acoustics began in 1490, when Leonar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate causes of phenomena, and usually frame their understanding in mathematical terms. Physicists work across a wide range of research fields, spanning all length scales: from sub-atomic and particle physics, through biological physics, to cosmological length scales encompassing the universe as a whole. The field generally includes two types of physicists: experimental physicists who specialize in the observation of natural phenomena and the development and analysis of experiments, and theoretical physicists who specialize in mathematical modeling of physical systems to rationalize, explain and predict natural phenomena. Physicists can apply their knowledge towards solving practical problems or to developing new technologies (also known as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Beaumont Wood
Albert Beaumont Wood DSc (1890 – 19 July 1964), better known as A B Wood, was a British physicist, known for his pioneering work in the field of underwater acoustics and sonar. Wood is known for his work on developing sonar (known at that time as 'ASDICS') in the UK from the First World War until after the Second World War. Education He graduated from Manchester University with First Class Honours in 1912, where he joined a team of notable scientists led by Sir Ernest Rutherford (later Lord Rutherford), including Henry Moseley, Hans Geiger, Niels Bohr, Ernest Marsden, James Chadwick, George de Hevesy and Charles Galton Darwin. In 1914 he was appointed a research fellow at the University of Liverpool and then a lecturer in physics. He still kept in touch with Rutherford, who was working on underwater acoustics, and arranged for him to work on countering the German naval threat. He was awarded his DSc degree by his university in 1919 and became a Fellow of the Physic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Langevin
Paul Langevin (; ; 23 January 1872 – 19 December 1946) was a French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the ''Comité de vigilance des intellectuels antifascistes'', an anti-fascist organization created after the 6 February 1934 far right riots. Being a public opponent of fascism in the 1930s resulted in his arrest and being held under house arrest by the Vichy government for most of World War II. Langevin was also president of the Human Rights League (LDH) from 1944 to 1946, having recently joined the French Communist Party. He was a doctoral student of Pierre Curie and later a lover of widowed Marie Curie. He is also known for his two US patents with Constantin Chilowsky in 1916 and 1917 involving ultrasonic submarine detection. He is entombed at the Panthéon. Life Langevin was born in Paris, and studied at the '' École de Physique et Chimie'' and the '' École Normale Supérieure''. He then we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reginald A
Reginald is a masculine given name in the English language. Etymology and history The meaning of Reginald is “King". The name is derived from the Latin ''Reginaldus'', which has been influenced by the Latin word ''regina'', meaning "queen". This Latin name is a Latinisation of a Germanic language name. This Germanic name is composed of two elements: the first ''ragin'', meaning "advice", "counsel", "decision"; the second element is ''wald'', meaning "rule", "ruler". The Old German form of the name is ''Raginald''; Old French forms are ''Reinald'' and ''Reynaud''. Forms of this Germanic name were first brought to the British Isles by Scandinavians, in the form of the Old Norse ''Rögnvaldr''. This name was later reinforced by the arrival of the Normans in the 11th century, in the Norman forms ''Reinald'' and ''Reynaud''. which cited: for the surname "Reynold". The Latin ''Reginaldus'' was used as a Latin form of cognate names, such as the Old Norse ''Rögnvaldr'', and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-boat
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role ( commerce raiding) and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States, to the United Kingdom and (during the Second World War) to the Soviet Union and the Allied territories in the Mediterranean. German submarines also destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on both Germany and Italy on 22 August 1942. The term is an anglicised version of the German word ''U-Boot'' , a shortening of ''Unterseeboot'' ('under-sea-boat'), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iceberg
An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The sinking of the ''Titanic'' in 1912 led to the formation of the International Ice Patrol in 1914. Much of an iceberg is below the surface, which led to the expression " tip of the iceberg" to illustrate a small part of a larger unseen issue. Icebergs are considered a serious maritime hazard. Icebergs vary considerably in size and shape. Icebergs that calve from glaciers in Greenland are often irregularly shaped while Antarctic ice shelves often produce large tabular (table top) icebergs. The largest iceberg in recent history (2000), named B-15, measured nearly 300 km × 40 km. The largest iceberg on record was an Antarctic tabular iceberg of over [] sighted west of Scott Island, in the South Pacific Ocean, by the USS Glacie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific Ocean, Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in Genocides in history (World War I through World War II), genocides within the Ottoman Empire and in the Spanish flu, 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising French Third Republic, France, Russia, and British Empire, Britain) and the Triple A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RMS Titanic
RMS ''Titanic'' was a British passenger Ocean liner, liner, operated by the White Star Line, which Sinking of the Titanic, sank in the North Atlantic Ocean on 15 April 1912 after striking an iceberg during her maiden voyage from Southampton, England, to New York City, United States. Of the Sinking of the Titanic#Casualties and survivors, estimated 2,224 passengers and crew aboard, more than 1,500 died, making it List of maritime disasters, the deadliest sinking of a single ship up to that time. It remains the deadliest peacetime sinking of a superliner (passenger ship), superliner or cruise ship. The disaster drew public attention, provided foundational material for the disaster film genre, and has inspired many artistic works. Royal Mail Ship, RMS ''Titanic'' was the Timeline of largest passenger ships, largest ship afloat at the time she entered service and the second of three s operated by the White Star Line. She was built by the Harland and Wolff shipyard in Belfast. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annales De Chimie Et De Physique
__NOTOC__ ''Annales de chimie et de physique'' ( French for ''Annals of Chemistry and Physics'') is a scientific journal founded in Paris, France, in 1789 under the title ''Annales de chimie''. One of the early editors was the French chemist Antoine Lavoisier. Lavoisier, an aristocrat, was guillotined in May 1794, ostensibly for tax fraud: and the journal was not published from 1794 to 1796 while the Reign of Terror was at its height under the French Directory. In 1815, it became the ''Annales de chimie et de physique'', and was published under that name for the next 100 years. In 1914, it split into two successor journals. The first one, '' Annales de physique'', was latterly published by EDP Sciences under the same name up to 2009, when it became integrated in the ''European Physical Journal'' series as the '' European Physical Journal H – Historical Perspectives on Contemporary Physics''. The second successor, ''Annales de chimie'', later became '' Annales de chimie: Scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Geneva
, image = Lake Geneva by Sentinel-2.jpg , caption = Satellite image , image_bathymetry = , caption_bathymetry = , location = Switzerland, France , coords = , lake_type = Glacial lake , inflow = Rhône, Dranse (Haute-Savoie), Dranse , outflow = Rhône , catchment = , basin_countries = Switzerland, France , length = , width = , area = , depth = , max-depth = , volume = , residence_time = 11.4 years , shore = , elevation = , islands = Île de Peilz, Château de Chillon, Île de Salagnon, Île de la Harpe, Île Rousseau, Île de Choisi , cities = Geneva (CH), Lausanne (CH), Évian-les-Bains, Évian (F), Montreux (CH), Thonon-les-Bains, Thonon (F), Vevey (CH) (''see #Cities and places, list'') , pushpin_map=France Rhône-Alpes#Canton of Vaud#Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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