Geographical pole

A geographical pole is either of the two points on a rotating body (planet, dwarf planet, natural satellite, sphere...etc) where its axis of rotation intersects its surface.[1] As with Earth's North and South Poles, they are usually called that body's "north pole" and "south pole", one lying 90 degrees in one direction from the body's equator and the other lying 90 degrees in the opposite direction from the equator.

Every planet has geographical poles.[2] If, like the Earth, a body generates a magnetic field, it will also possess magnetic poles.[3]

Perturbations in a body's rotation mean that geographical poles wander slightly on its surface. The Earth's North and South Poles, for example, move by a few metres over periods of a few years.[4][5] As cartography requires exact and unchanging coordinates, the averaged locations of geographical poles are taken as fixed cartographic poles and become the points where the body's great circles of longitude intersect.

Geographical and Magnetic Poles
A geographical axis of rotation A (green), and showing the north geographical pole A1, and south geographical pole A2; also showing a magnetic field and the magnetic axis of rotation B (blue), and the north magnetic pole B2, and south magnetic pole B1.

See also

References

  1. ^ Kotlyakov, Vladimir; Komarova, Anna (2006). Elsevier's Dictionary of Geography: in English, Russian, French, Spanish and German. p. 557. Retrieved 22 June 2015.
  2. ^ Hooper, William (2008). Aether and Gravitation. p. 224. Retrieved 22 June 2015.
  3. ^ "20 Things You Didn't Know About... the North Pole". DiscoverMagazine.com. 2014-11-18. Retrieved 2015-06-26.
  4. ^ Schar, Ray (2010). Wonderfully Weird World. p. 106. Retrieved 22 June 2015.
  5. ^ Lovett, Richard A. (2013-05-14). "Climate Change Has Shifted the Locations of Earth's North and South Poles". Scientificamerican.com. Retrieved 2015-06-26.
Chronometric singularity

A chronometric singularity (also called a temporal or horological singularity) is a point at which time cannot be measured or described.

An example involves a time at a coordinate singularity, e.g.a geographical pole. Since time on Earth is measured through longitudes, and no unique longitude exists at a pole, time is not defined uniquely at this point. There is a clear connection with coordinate singularities, as can be seen from this example. In relativity, similar singularities can be found in the case of Schwarzschild coordinates.

Stephen Hawking once compared by a talk-show guest's question about "before the beginning of time" to asking "what's north of the north pole".

Dennis Rawlins

Dennis Rawlins (born 1937) is an American astronomer and historian who has acquired the reputation of skeptic primarily with respect to historical claims connected to astronomical considerations. He is known to the public mostly from media coverage of his investigations of the two most,

successful science hoaxes of the twentieth century. In his first book, Peary at the North Pole: fact or fiction? (1973), Rawlins argued that Robert Peary never made it to the North Pole in 1909. His second book (1993) is the standard critical edition of Tycho Brahe's 1598 catalogue of 1004 stars which detected ten star places faked partially or entirely. In 1976, as the only astronomer on the Committee for Skeptical Inquiry, he looked into the so-called Mars effect. In 1996 he made headlines when page one of the New York Times covered his report to Ohio State University which concluded that in 1926 Richard E. Byrd's airplane flight towards the North Pole turned back 150 miles from the pole. Rawlins's third book, his detailed report on Byrd's trip and on the competence of lingering defenses of it, was co-published simultaneously in 2000 by DIO volume 10, 2000 and by the polar research center at the University of Cambridge. Because explorer Frederick Cook's story of reaching the North Pole in 1908 is generally rejected, the elimination of Peary and Byrd leaves fourth North Pole claimant Roald Amundsen as first there in 1926 in the airship Norge (Norwegian for Norway). Having attained the South Pole in 1911, Amundsen thus became the first to reach each geographical pole of the earth, as proposed in Rawlins's 1973 book.

Historic Sites and Monuments in Antarctica

A Historic Site or Monument (HSM) is a protected location of historic interest on the continent of Antarctica, or on its adjacent islands. The list of historic sites was first drawn up in 1972, and has since expanded to cover 92 sites, with the most recent listed in 2015. Five sites have been removed from the list for various reasons.

Historic Sites and Monuments are protected under the Antarctic Treaty System, as one of three classes of Antarctic Protected Areas.The criteria for listing a site are that it should fulfil one or more of the following criteria:

a) a particular historic event occurred at that location;

b) it is associated with a significant person in Antarctic history;

c) it is associated with a significant feat of "endurance or achievement";

d) it is representative of a wider activity "important in the development and knowledge of Antarctica";

e) the building itself is of intrinsic technical, historical, cultural or architectural significance;

f) it has educational potential about "significant human activities" in Antarctica; or that

g) it has "symbolic or commemorative value for people of many nations"

Outline of geography

The following outline is provided as an overview of and topical guide to geography:

Geography – study of earth and its people.

Pole of inaccessibility

A pole of inaccessibility with respect to a geographical criterion of inaccessibility marks a location that is the most challenging to reach according to that criterion. Often it refers to the most distant point from the coastline, implying a maximum degree of continentality or oceanity. In these cases, pole of inaccessibility can be defined as the center of the largest circle that can be drawn within an area of interest without encountering a coast. Where a coast is imprecisely defined, the pole will be similarly imprecise.

Poles (disambiguation)

Poles may refer to:

Geographical pole

Poles of astronomical bodies

Poles, the people originating from or inhabiting Poland

Prospective Outlook on Long-term Energy Systems (POLES)

Spot Poles (1887–1962), an American outfielder in baseball's Negro Leagues

plural form of pole

Roald Amundsen

Roald Engelbregt Gravning Amundsen (UK: , US: ; 16 July 1872 – c. 18 June 1928) was a Norwegian explorer of polar regions and a key figure of the Heroic Age of Antarctic Exploration. He led the first expedition to traverse the Northwest Passage in 1906 and the first expedition to the South Pole in 1911. He possibly led the first expedition to reach the North Pole in 1926; the expedition of 1926 is the earliest expedition proven to have reached the North Pole. He disappeared while taking part in a rescue mission for the airship Italia in 1928.

South Pole

The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface. It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole.

Situated on the continent of Antarctica, it is the site of the United States Amundsen–Scott South Pole Station, which was established in 1956 and has been permanently staffed since that year. The Geographic South Pole is distinct from the South Magnetic Pole, the position of which is defined based on the Earth's magnetic field. The South Pole is at the center of the Southern Hemisphere.

Taiji (philosophy)

Taiji (simplified Chinese: 太极; traditional Chinese: 太極; pinyin: tàijí; literally: 'great pole') is a Chinese cosmological term for the "Supreme Ultimate" state of undifferentiated absolute and infinite potential, the oneness before duality, from which Yin and Yang originate, can be compared with the old Wuji (無極, "without ridgepole").

The term Taiji and its other spelling T'ai chi (using Wade–Giles as opposed to Pinyin) are most commonly used in the West to refer to Taijiquan (or T'ai chi ch'uan, 太極拳), an internal martial art, Chinese meditation system and health practice. This article, however, refers only to the use of the term in Chinese philosophy and in Confucianism, Taoism and Buddhism.

Tree line

The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures or associated lack of available moisture). The tree line is sometimes distinguished from a lower timberline or forest line, which is the line below which trees form a forest with a closed canopy.At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as krummholz (German for "crooked wood").The tree line often appears well-defined, but it can be a more gradual transition. Trees grow shorter and often at lower densities as they approach the tree line, above which they cease to exist.

Weddell Island

Weddell Island (Spanish: Isla San José) is one of the Falkland Islands in the South Atlantic, lying off the southwest extremity of West Falkland. It is situated 1,545 km (960 mi) west-northwest of South Georgia Island, 1,165 km (724 mi) north of Livingston Island, 606 km (377 mi) northeast of Cape Horn, 358 km (222 mi) northeast of Isla de los Estados, and 510 km (320 mi) east of the Atlantic entrance to Magellan Strait.

With an area of 265.8 km2 (102.6 sq mi) Weddell is the third largest island in the archipelago after East Falkland and West Falkland, and one of the largest private islands in the world. It has only one inhabited location, Weddell Settlement, with a single digit population engaged in sheep farming and tourism services. The island offers walks to wildlife watching sites and scenery destinations including landscapes featuring stone runs. Weddell is both an Important Plant Area and a priority Key Biodiversity Area.

It is a remote place, infrequently visited by a resupply ship and occasionally by private yachts, accessible by air with a 200 km (120 mi) flight from the Falklands capital, Stanley.

Wuji (philosophy)

Wújí (simplified Chinese: 无极; traditional Chinese: 無極; literally "without ridgepole") originally meant "ultimate; boundless; infinite" in Warring States period (476–221 BCE) Taoist classics, but came to mean the "primordial universe" prior to the Taiji 太極 "Supreme Ultimate" in Song Dynasty (960–1279 CE) Neo-Confucianist cosmology. Wuji is also a proper noun in Modern Standard Chinese usage; for instance, Wuji County in Hebei.

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