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Pole Star
A pole star is a visible star that is approximately aligned with the axis of rotation of an astronomical body; that is, a star whose apparent position is close to one of the celestial poles. On Earth, a pole star would lie directly overhead when viewed from the North or the South Pole. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dhruva
Dhruva (Sanskrit: ध्रुव, , Literal translation, lit. "''unshakeable, immovable, fixed or eternal"'') was an Asceticism, ascetic devotee of Vishnu mentioned in the Vishnu Purana and the Bhagavata Purana. The Sanskrit term ''dhruva nakshatra'' (ध्रुव नक्षत्र, "polar star") has been used for Pole_star#In_religion_and_mythology, Pole Star in the Mahabharata, personified as son of Uttānapāda and grandson of Manu (Hinduism), Manu, even though Polaris at the likely period of the recension of the text of the Mahabharata was still several degrees away from the celestial pole. Narrative Devotion towards Vishnu Dhruva was born as son of the King Uttānapāda (the son of Svayambhuva Manu) and his wife Suniti. The king also had another son Uttama, born to his second queen Suruchi, who was the preferred object of his affection. Once, when Dhruva was five years old, he saw his younger brother, Uttama sitting on his father's lap at the King's throne. Su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Trail Above Beccles - Geograph
A star is a luminous spheroid of plasma held together by self-gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night; their immense distances from Earth make them appear as fixed points of light. The most prominent stars have been categorised into constellations and asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye—all within the Milky Way galaxy. A star's life begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its total mass mainly determines its evolution and eventual fate. A star shines for most of its active life due to the thermonuclear fusion of hydrogen into helium in its core. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Antiquity
Classical antiquity, also known as the classical era, classical period, classical age, or simply antiquity, is the period of cultural History of Europe, European history between the 8th century BC and the 5th century AD comprising the interwoven civilizations of ancient Greece and ancient Rome, Rome known together as the Greco-Roman world, centered on the Mediterranean Basin. It is the period during which ancient Greece and Rome flourished and had major influence throughout much of Europe, North Africa, and West Asia. Classical antiquity was succeeded by the period now known as late antiquity. Conventionally, it is often considered to begin with the earliest recorded Homeric Greek, Epic Greek poetry of Homer (8th–7th centuries BC) and end with the fall of the Western Roman Empire in 476 AD. Such a wide span of history and territory covers many disparate cultures and periods. ''Classical antiquity'' may also refer to an idealized vision among later people of what was, in Ed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Declination
In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or south (negative) of the celestial equator, along the hour circle passing through the point in question. The root of the word ''declination'' (Latin, ''declinatio'') means "a bending away" or "a bending down". It comes from the same root as the words ''incline'' ("bend forward") and ''recline'' ("bend backward"). In some 18th and 19th century astronomical texts, declination is given as ''North Pole Distance'' (N.P.D.), which is equivalent to 90 – (declination). For instance an object marked as declination −5 would have an N.P.D. of 95, and a declination of −90 (the south celestial pole) would have an N.P.D. of 180. Explanation Declination in astronomy is comparable to geographic latitude, projected onto the celestial sphere, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Precession
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering Water distribution on Earth, 70.8% of Earth's crust. The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere. Most of Earth's land is at least somewhat humid and covered by vegetation, while large Ice sheet, sheets of ice at Polar regions of Earth, Earth's polar polar desert, deserts retain more water than Earth's groundwater, lakes, rivers, and Water vapor#In Earth's atmosphere, atmospheric water combined. Earth's crust consists of slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's outer core, Earth has a liquid outer core that generates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemma Frisius
Gemma Frisius (; born Jemme Reinerszoon; December 9, 1508 – May 25, 1555) was a Dutch physician, mathematician, cartographer, philosopher, and instrument maker. He created important globes, improved the mathematical instruments of his day and applied mathematics in new ways to surveying and navigation. Gemma's rings, an astronomical instrument, are named after him. Along with Gerardus Mercator and Abraham Ortelius, Frisius is often considered one of the founders of the Netherlandish school of cartography, and significantly helped lay the foundations for the school's golden age (approximately 1570s–1670s). Biography Frisius was born in Dokkum, Friesland (present-day Netherlands), of poor parents who died when he was young. He moved to Groningen and later studied at the University of Leuven (Louvain), Belgium, beginning in 1525. He received the degree of MD in 1536 and remained on the faculty of medicine of Leuven for the rest of his life where, in addition to teaching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purana
Puranas (Merriam-Webster's Encyclopedia of Literature (1995 Edition), Article on "Puranas", , page 915) are a vast genre of Indian literature that include a wide range of topics, especially legends and other traditional lore. The Puranas are known for the intricate layers of symbolism depicted within their stories. Composed originally in Sanskrit and in Languages of India, other Indian languages,John Cort (1993), "An Overview of the Jaina Puranas" in ''Purana Perennis: Reciprocity and Transformation in Hindu and Jaina Texts,'' (Editor: Wendy Doniger), State University of New York Press, , pages 185-204 several of these texts are named after major Hindu deities such as Vishnu, Shiva, Brahma, and Mahadevi, Devi. The Puranic genre of literat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anglo-Saxon England
Anglo-Saxon England or early medieval England covers the period from the end of Roman Empire, Roman imperial rule in Roman Britain, Britain in the 5th century until the Norman Conquest in 1066. Compared to modern England, the territory of the Anglo-Saxons stretched north to present day Lothian in southeastern Scotland, whereas it did not initially include western areas of England such as Cornwall, Herefordshire, Shropshire, Cheshire, Lancashire, and Cumbria. The 5th and 6th centuries involved the collapse of economic networks and political structures and also saw a radical change to a new Anglo-Saxon language and culture. This change was driven by movements of peoples as well as changes which were happening in both northern Gaul and the North Sea coast of what is now Germany and the Netherlands. The Anglo-Saxon language, also known as Old English, was a close relative of languages spoken in the latter regions, and genetic studies have confirmed that there was significant migrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stobaeus
Joannes Stobaeus (; ; 5th-century AD), from Stobi in Macedonia (Roman province), Macedonia, was the compiler of a valuable series of extracts from Greek authors. The work was originally divided into two volumes containing two books each. The two volumes became separated in the manuscript tradition, and the first volume became known as the ''Extracts'' (also ''Eclogues'') and the second volume became known as the ''Anthology'' (also ''Florilegium''). Modern editions now refer to both volumes as the ''Anthology''. The ''Anthology'' contains extracts from hundreds of writers, especially poets, historians, orators, philosophers and physicians. The subjects range from natural philosophy, dialectics, and ethics, to politics, economics, and maxims of practical wisdom. The work preserves fragments of many authors and works which otherwise might be unknown today. Life Nothing of his life is known. The age in which he lived cannot be fixed with accuracy.Mason 1870, pp. 914–5 He quotes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Kepler
Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, Natural philosophy, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his Kepler's laws of planetary motion, laws of planetary motion, and his books ''Astronomia nova'', ''Harmonice Mundi'', and ''Epitome Astronomiae Copernicanae'', influencing among others Isaac Newton, providing one of the foundations for his theory of Newton's law of universal gravitation, universal gravitation. The variety and impact of his work made Kepler one of the founders and fathers of modern astronomy, the scientific method, Natural science, natural and modern science. He has been described as the "father of science fiction" for his novel ''Somnium (novel), Somnium''. Kepler was a mathematics teacher at a seminary school in Graz, where he became an associate of Hans Ulrich von Eggenberg, Prince Hans Ulrich von Eggenberg. Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoenicians
Phoenicians were an ancient Semitic group of people who lived in the Phoenician city-states along a coastal strip in the Levant region of the eastern Mediterranean, primarily modern Lebanon and the Syrian coast. They developed a maritime civilization which expanded and contracted throughout history, with the core of their culture stretching from Arwad in modern Syria to Mount Carmel. The Phoenicians extended their cultural influence through trade and colonization throughout the Mediterranean, from Cyprus to the Iberian Peninsula, evidenced by thousands of Phoenician inscriptions. The Phoenicians directly succeeded the Bronze Age Canaanites, continuing their cultural traditions after the decline of most major Mediterranean basin cultures in the Late Bronze Age collapse and into the Iron Age without interruption. They called themselves Canaanites and referred to their land as Canaan, but the territory they occupied was notably smaller than that of Bronze Age Canaan. The name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
