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Prime Meridian
A prime meridian is an arbitrarily chosen meridian (geography), meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. On a spheroid, a prime meridian and its anti-meridian (the 180th meridian in a degree (angle), 360°-system) form a great ellipse. This divides the body (e.g. Earth) into hemispheres of Earth, two hemispheres: the Eastern Hemisphere and the Western Hemisphere (for an east-west notational system). For Earth's prime meridian, various conventions have been used or advocated in different regions throughout history. Earth's current international standard prime meridian is the IERS Reference Meridian. It is derived, but differs slightly, from the Prime meridian (Greenwich), Greenwich Meridian, the previous standard. Longitudes for the Earth and Moon are measured from their prime meridian (at 0°) to 180° east and west. For all other Solar System bodies, longitude is measured from 0° (their prime meridian) to 360� ...
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Equator And Prime Meridian
The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumference, halfway between the North Pole, North and South Pole, South poles. The term can also be used for any other celestial body that is roughly spherical. In three-dimensional space, spatial (3D) geometry, as applied in astronomy, the equator of a rotating spheroid (such as a planet) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is an imaginary line on the spheroid, equidistant from its geographical pole, poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane (geometry), plane perpendicular to its axis of rotation and midway between its geographical poles. On and near the equator (on Earth), noontime sunlight appears almost directly o ...
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IERS Reference Meridian
The IERS Reference Meridian (IRM), also called the International Reference Meridian, is the prime meridian (0° longitude) maintained by the International Earth Rotation and Reference Systems Service (IERS). It passes about 5.3 arcseconds east of George Biddell Airy's 1851 transit circle, and thus it differs slightly from the historical Greenwich Meridian. At the latitude of the Royal Observatory, Greenwich the difference is . It is the reference meridian of the Global Positioning System (GPS) operated by the United States Space Force, and of WGS 84 and its two formal versions, the ideal International Terrestrial Reference System (ITRS) and its realization, the International Terrestrial Reference Frame (ITRF). Location The most important reason for the 5.3 seconds of longitude offset between the IERS Reference Meridian and the Airy transit circle is that the observations with the transit circle were based on the astronomical longitude, while the IERS Reference ...
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Canary Islands
The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the continent being 100 kilometres (62 miles) away. The islands have a population of 2.25 million people and are the most populous overseas Special member state territories and the European Union, special territory of the European Union. The seven main islands are from largest to smallest in area, Tenerife, Fuerteventura, Gran Canaria, Lanzarote, La Palma, La Gomera, and El Hierro. The only other populated island is Graciosa, Canary Islands, La Graciosa, which administratively is dependent on Lanzarote. The archipelago includes many smaller islands and islets, including Alegranza, Islote de Lobos, Isla de Lobos, Montaña Clara, Roque del Oeste, and Roque del Este. It includes a number of rocks, including Roque de Garachico, Garachico and Roques de ...
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Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas (North America and South America) from the Old World of Afro-Eurasia (Africa, Asia, and Europe). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse colonization of North America, Norse were the first known humans to cross the Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus's expedition ushered in an Age of Discovery, age of exploration and colonization of the Americas by European powers, most notably Portuguese Empire, Portugal, Spanish Empire, Sp ...
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Fortunate Isles
The Fortunate Isles or Isles of the Blessed (, ''makarōn nēsoi'') were semi-legendary islands in the Atlantic Ocean, variously treated as a simple geographical location and as a winterless earthly paradise inhabited by the heroes of Greek mythology. In the time of Hesiod, the Fortunate Isles were associated with the concept of Elysium, a utopian location in the Greek underworld thought to be found in the Western ocean on the margin of the known world. The number of the islands would later be reduced to one by the poet Pindar. Legend According to Greek mythology, the islands were reserved for those who had chosen to be reincarnated three times, and managed to be judged as especially pure enough to gain entrance to the Elysian Fields all three times. The Theban poet Pindar reduced the number of the islands to one, describing it as having shady parklands with residents indulging in athletic and musical pastimes, activities that were thought to be the ideal life for ancient Gree ...
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Geography (Ptolemy)
The ''Geography'' (, ,  "Geographical Guidance"), also known by its Latin names as the ' and the ', is a gazetteer, an atlas (book), atlas, and a treatise on cartography, compiling the geographical knowledge of the 2nd-century Roman Empire. Originally written by Claudius Ptolemy in Ancient Greek, Greek at Alexandria around 150 AD, the work was a revision of a now-lost atlas by Marinus of Tyre using additional Roman and Parthian Empire, Persian gazetteers and new principles. Its translation – Al-Khwarizmi#Geography, Kitab Surat al-Ard – into Classical Arabic, Arabic by Al-Khwarizmi, Al-Khwarismi in the 9th century was highly influential on the geographical knowledge and cartographic traditions of the Geography and cartography in medieval Islam, Islamic world. Alongside the works of Islamic scholars – and the commentary containing revised and more accurate data by Alfraganus – Ptolemy's work was subsequently highly influential on Middle Ages, Medieval and Renaissanc ...
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Ptolemy
Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzantine, Islamic science, Islamic, and Science in the Renaissance, Western European science. The first was his astronomical treatise now known as the ''Almagest'', originally entitled ' (, ', ). The second is the ''Geography (Ptolemy), Geography'', which is a thorough discussion on maps and the geographic knowledge of the Greco-Roman world. The third is the astrological treatise in which he attempted to adapt horoscopic astrology to the Aristotelian physics, Aristotelian natural philosophy of his day. This is sometimes known as the ' (, 'On the Effects') but more commonly known as the ' (from the Koine Greek meaning 'four books'; ). The Catholic Church promoted his work, which included the only mathematically sound geocentric model of the Sola ...
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Strabo
Strabo''Strabo'' (meaning "squinty", as in strabismus) was a term employed by the Romans for anyone whose eyes were distorted or deformed. The father of Pompey was called "Gnaeus Pompeius Strabo, Pompeius Strabo". A native of Sicily so clear-sighted that he could see things at great distance as if they were nearby was also called "Strabo". (; ''Strábōn''; 64 or 63 BC) was an ancient Greece, ancient Greek geographer who lived in Anatolia, Asia Minor during the transitional period of the Roman Republic into the Roman Empire. He is best known for his work ''Geographica'', which presented a descriptive history of people and places from different regions of the world known during his lifetime. Additionally, Strabo authored historical works, but only fragments and quotations of these survive in the writings of other authors. Early life Strabo was born to an affluent family from Amasya, Amaseia in Kingdom of Pontus, Pontus in around 64BC. His family had been involved in politics s ...
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Geographer
A geographer is a physical scientist, social scientist or humanist whose area of study is geography, the study of Earth's natural environment and human society, including how society and nature interacts. The Greek prefix "geo" means "earth" and the Greek suffix, "graphy", meaning "description", so a geographer is someone who studies the earth. The word "geography" is a Middle French word that is believed to have been first used in 1540. Although geographers are historically known as people who make maps, map making is actually the field of study of cartography, a subset of geography. Geographers do not study only the details of the natural environment or human society, but they also study the reciprocal relationship between these two. For example, they study how the natural environment contributes to human society and how human society affects the natural environment. In particular, physical geographers study the natural environment while human geographers study human society ...
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Rhodes
Rhodes (; ) is the largest of the Dodecanese islands of Greece and is their historical capital; it is the List of islands in the Mediterranean#By area, ninth largest island in the Mediterranean Sea. Administratively, the island forms a separate municipality within the Rhodes (regional unit), Rhodes regional unit, which is part of the South Aegean Administrative regions of Greece, administrative region. The principal town of the island and seat of the municipality is the Rhodes (city), city of Rhodes, which had 50,636 inhabitants in 2011. In 2022, the island had a population of 125,113 people. It is located northeast of Crete and southeast of Athens. Rhodes has several nicknames, such as "Island of the Sun" due to its patron sun god Helios, "The Pearl Island", and "The Island of the Knights", named after the Knights Hospitaller, Knights of Saint John of Jerusalem, who ruled the island from 1310 to 1522. Historically, Rhodes was famous for the Colossus of Rhodes, one of the Sev ...
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Hipparchus
Hipparchus (; , ;  BC) was a Ancient Greek astronomy, Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the equinoxes. Hipparchus was born in Nicaea, Bithynia, and probably died on the island of Rhodes, Greece. He is known to have been a working astronomer between 162 and 127 BC. Hipparchus is considered the greatest ancient astronomical observer and, by some, the greatest overall astronomer of classical antiquity, antiquity. He was the first whose quantitative and accurate models for the motion of the Sun and Moon survive. For this he certainly made use of the observations and perhaps the mathematical techniques accumulated over centuries by the Babylonians and by Meton of Athens (fifth century BC), Timocharis, Aristyllus, Aristarchus of Samos, and Eratosthenes, among others. He developed trigonometry and constructed trigonometric tables, and he solved se ...
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Alexandria
Alexandria ( ; ) is the List of cities and towns in Egypt#Largest cities, second largest city in Egypt and the List of coastal settlements of the Mediterranean Sea, largest city on the Mediterranean coast. It lies at the western edge of the Nile Delta, Nile River delta. Founded in 331 BC by Alexander the Great, Alexandria grew rapidly and became a major centre of Hellenic civilisation, eventually replacing Memphis, Egypt, Memphis, in present-day Greater Cairo, as Egypt's capital. Called the "Bride of the Mediterranean" and "Pearl of the Mediterranean Coast" internationally, Alexandria is a popular tourist destination and an important industrial centre due to its natural gas and petroleum, oil pipeline transport, pipelines from Suez. The city extends about along the northern coast of Egypt and is the largest city on the Mediterranean, the List of cities and towns in Egypt#Largest cities, second-largest in Egypt (after Cairo), the List of largest cities in the Arab world, fourth- ...
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