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Magnetic North
The north magnetic pole, also known as the magnetic north pole, is a point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downward (in other words, if a magnetic compass needle is allowed to rotate in three dimensions, it will point straight down). There is only one location where this occurs, near (but distinct from) the geographic north pole. The geomagnetic north pole is the northern antipodal pole of an ideal dipole model of the Earth's magnetic field, which is the most closely fitting model of Earth's actual magnetic field. The north magnetic pole moves over time according to magnetic changes and flux lobe elongation in the Earth's outer core. In 2001, it was determined by the Geological Survey of Canada to lie west of Ellesmere Island in northern Canada at . It was situated at in 2005. In 2009, while still situated within the Canadian Arctic at , it was moving toward Russia at between per year. As of 2021, the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Magnetic Poles
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is related to the Old High German ''nord'', both descending from the Proto-Indo-European unit *''ner-'', meaning "left; below" as north is to left when facing the rising sun. Similarly, the other cardinal directions are also related to the sun's position. The Latin word ''borealis'' comes from the Greek '' boreas'' "north wind, north", which, according to Ovid, was personified as the wind-god Boreas, the father of Calais and Zetes. ''Septentrionalis'' is from ''septentriones'', "the seven plow oxen", a name of ''Ursa Major''. The Greek ἀρκτικός (''arktikós'') is named for the same constellation, and is the source of the English word ''Arctic''. Other languages have other derivations. For example, in Lezgian, ''kefer'' can mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Dip
Magnetic dip, dip angle, or magnetic inclination is the angle made with the horizontal by the Earth's magnetic field lines. This angle varies at different points on the Earth's surface. Positive values of inclination indicate that the magnetic field of the Earth is pointing downward, into the Earth, at the point of measurement, and negative values indicate that it is pointing upward. The dip angle is in principle the angle made by the needle of a vertically held compass, though in practice ordinary compass needles may be weighted against dip or may be unable to move freely in the correct plane. The value can be measured more reliably with a special instrument typically known as a dip circle. Dip angle was discovered by the engineer Georg Hartmann in 1544. A method of measuring it with a dip circle was described by Robert Norman in England in 1581. Explanation Magnetic dip results from the tendency of a magnet to align itself with lines of magnetic field. As the Earth's magne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir John Ross
Sir John Ross (24 June 1777 – 30 August 1856) was a Scottish Royal Navy officer and polar explorer. He was the uncle of Sir James Clark Ross, who explored the Arctic with him, and later led expeditions to Antarctica. Biography Early life John Ross was born in Balsarroch, West Galloway, Scotland, on , the son of the Reverend Andrew Ross of Balsarroch, Minister of Inch in Wigtownshire, and Elizabeth Corsane, daughter of Robert Corsane, the Provost of Dumfries. His family home was on the shore of Loch Ryan, at Stranraer. Naval career In 1786, aged nine, Ross joined the Royal Navy as a first-class volunteer and was assigned to . It soon sailed to the Mediterranean Sea, where it remained until 1789. He then served aboard for several months before a transfer to the merchant marine for eight years. In September 1799 he was recalled to the Navy and appointed midshipman on HMS ''Weazel'', which shortly joined in the Anglo-Russian invasion of Holland. Short per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boothia Peninsula
Boothia Peninsula (; formerly ''Boothia Felix'', Inuktitut ''Kingngailap Nunanga'') is a large peninsula in Nunavut's northern Canadian Arctic, south of Somerset Island. The northern part, Murchison Promontory, is the northernmost point of mainland Canada. Geography Bellot Strait (Ikirahaq) separates the peninsula from Somerset Island to the north. Babbage Bay is on the east coast, as is Abernethy Bay, just to the south. The community of Taloyoak lies in the far south and is the peninsula's only significant population centre. Paisley Bay is on the west coast, as is Wrottesley Inlet (between Paisley Bay and Bellot Strait). Prior to the detachment of Nunavut in 1999, the Boothia Peninsula and the nearby Melville Peninsula were the only parts of mainland Canada that belonged to the District of Franklin in the then Northwest Territories. The balance of the District of Franklin was all situated within the Arctic Archipelago. Exploration John Ross was forced by ice to stop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Clark Ross
Sir James Clark Ross (15 April 1800 – 3 April 1862) was a British Royal Navy officer and polar explorer known for his explorations of the Arctic, participating in two expeditions led by his uncle John Ross, and four led by William Edward Parry, and, in particular, for his own Antarctic expedition from 1839 to 1843. Biography Early life Ross was born in London, the son of George Ross and nephew of John Ross, under whom he entered the Royal Navy on 5 April 1812. Ross was an active participant in the Napoleonic Wars, being present at an action where HMS ''Briseis'', commanded by his uncle, captured ''Le Petit Poucet'' (a French privateer) on 9 October 1812. Ross then served successively with his uncle on HMS ''Actaeon'' and HMS ''Driver''. Arctic exploration Ross participated in John's unsuccessful first Arctic voyage in search of a Northwest Passage in 1818 aboard ''Isabella''. Between 1819 and 1827 Ross took part in four Arctic expeditions under William Ed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Gilbert (physician)
William Gilbert (; 24 May 1544? – 30 November 1603), also known as Gilberd, was an English physician, physicist and natural philosopher. He passionately rejected both the prevailing Aristotelian philosophy and the Scholastic method of university teaching. He is remembered today largely for his book '' De Magnete'' (1600). A unit of magnetomotive force, also known as magnetic potential, was named the ''Gilbert'' in his honour. Life and work Gilbert was born in Colchester to Jerome Gilberd, a borough recorder. He was educated at St John's College, Cambridge. After gaining his MD from Cambridge in 1569, and a short spell as bursar of St John's College, he left to practice medicine in London and travelled on the continent. In 1573, he was elected a Fellow of the Royal College of Physicians. In 1600 he was elected President of the college.Mottelay, P. Fleury (1893). "Biographical memoir". In He was Elizabeth I's own physician from 1601 until her death in 1603, and Jam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pole Star
A pole star or polar star is a star, preferably bright, nearly aligned with the axis of a rotating astronomical body. Currently, Earth's pole stars are Polaris (Alpha Ursae Minoris), a bright magnitude-2 star aligned approximately with its northern axis that serves as a pre-eminent star in celestial navigation, and a much dimmer magnitude-5.5 star on its southern axis, Polaris Australis (Sigma Octantis). From around 1700 BC until just after 300 AD, Kochab (Beta Ursae Minoris) and Pherkad (Gamma Ursae Minoris) were twin northern pole stars, though neither was as close to the pole as Polaris is now. History In classical antiquity, Beta Ursae Minoris (Kochab) was closer to the celestial north pole than Alpha Ursae Minoris. While there was no naked-eye star close to the pole, the midpoint between Alpha and Beta Ursae Minoris was reasonably close to the pole, and it appears that the entire constellation of Ursa Minor, in antiquity known as '' Cynosura'' (Greek Κυνό� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polaris
Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris ( Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an apparent magnitude that fluctuates around 1.98, it is the brightest star in the constellation and is readily visible to the naked eye at night. The position of the star lies less than 1° away from the north celestial pole, making it the current northern pole star. The stable position of the star in the Northern Sky makes it useful for navigation. As the closest Cepheid variable its distance is used as part of the cosmic distance ladder. The revised '' Hipparcos'' stellar parallax gives a distance to Polaris of about , while the successor mission ''Gaia'' gives a distance of about . Calculations by other methods vary widely. Although appearing to the naked eye as a single point of light, Polaris is a triple star system, composed of the primary, a yellow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupes Nigra
Rupes (plural ) is the Latin word for 'cliff'. It is used in planetary geology to refer to escarpments on other worlds. , the IAU has named 62 such features in the Solar System, on Mercury (17), Venus (7), the Moon (8), Mars (23), the asteroids Vesta (2) and Lutetia (2), and Uranus's satellites Miranda (2) and Titania (1). How rupes formed is, , a matter of speculation. Compressional strain from the cooling of the crust of terrestrial planets and large scale displacement due to impacts are the two dominant theories. See also * Rupes on the Earth's moon * Rupes on Mercury * Rupes on Venus * Rousillon Rupes * Rupes Tenuis * Verona Rupes Verona Rupes is a cliff on Miranda, a moon of Uranus. It was discovered by the ''Voyager 2'' space probe in January 1986. The cliff face, previously thought to be from high, as of 2016 is estimated to be high, which makes it the tallest known ... References Planetary geology Slope landforms * {{Geology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starkad
''Starkad'' ( non, Starkaðr or ; Latin: ''Starcaterus''; in the Late Middle Ages also ''Starkodder''; modern Danish: ''Stærkodder'')The article ''Starkad'' in ''Nationalencyklopedin''. was either an eight-armed giant or the human grandson of the aforementioned giant in Norse mythology. Starkad appears in numerous accounts, and the stories of his adventures relate to different Scandinavian traditions. He is most fully treated in ''Gesta Danorum'' but he also appears in Icelandic sources. He is portrayed as a great warrior who performed many heroic deeds but also many crimes. A cognate of the Starkad legends can be found in the Anglo-Saxon poem ''Beowulf''.Andersson, Ingvar. (1947). ''Skånes historia: till Saxo och Skånelagen''. Norstedts, Stockholm. p. 210. ''Beowulf'' In ''Beowulf'', the feud between the Danes and the Heaðobards was to be ended with the marriage of Ingeld, the son of the fallen Heaðobard king Froda, and Freawaru, the daughter of the Danish king Hro� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearings which are commonly stated in degrees. If local variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty (since c. 206 BC), Li Shu-hua, p. 176 and later adopted for navigation by the Song Dynasty Chinese during the 11th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Flux
In physics, specifically electromagnetism, the magnetic flux through a surface is the surface integral of the normal component of the magnetic field B over that surface. It is usually denoted or . The SI unit of magnetic flux is the weber (Wb; in derived units, volt–seconds), and the CGS unit is the maxwell. Magnetic flux is usually measured with a fluxmeter, which contains measuring coils and electronics, that evaluates the change of voltage in the measuring coils to calculate the measurement of magnetic flux. Description The magnetic interaction is described in terms of a vector field, where each point in space is associated with a vector that determines what force a moving charge would experience at that point (see Lorentz force). Since a vector field is quite difficult to visualize at first, in elementary physics one may instead visualize this field with field lines. The magnetic flux through some surface, in this simplified picture, is proportional to the nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
