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Sublunar
In Aristotelian physics and Greek astronomy, the sublunary sphere is the region of the geocentric cosmos below the Moon, consisting of the four classical elements: earth, water, air, and fire. The sublunary sphere was the realm of changing nature. Beginning with the Moon, up to the limits of the universe, everything (to classical astronomy) was permanent, regular and unchanging—the region of aether where the planets and stars are located. Only in the sublunary sphere did the powers of physics hold sway. Evolution of concept Plato and Aristotle helped to formulate the original theory of a sublunary sphere in antiquity, the idea usually going hand in hand with geocentrism and the concept of a spherical Earth. Avicenna carried forward into the Middle Ages the Aristotelian idea of generation and corruption being limited to the sublunary sphere. Medieval scholastics like Thomas Aquinas, who charted the division between celestial and sublunary spheres in his work ''Summa Theolog ...
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Ancient Greek Astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the Ancient Greece, Ancient Greek, Hellenistic civilization, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greek people, Greeks, as the Greek language had become the language of scholarship throughout the Hellenistic world following the conquests of Alexander the Great, Alexander. This phase of Greek astronomy is also known as Hellenistic astronomy, while the pre-Hellenistic phase is known as Classical Greek astronomy. During the Hellenistic and Roman periods, much of the Greek and non-Greek astronomers working in the Greek tradition studied at the Musaeum, Museum and the Library of Alexandria in Ptolemaic Egypt. The development of astronomy by the Greek and notably Hellenistic astronomers is considered to be a major phase in the history of astronomy. Greek astronomy is characterized by seeking a ge ...
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Sphere Of Fire
Sphere of fire is the name given in Ptolemaic astronomy to the sphere intervening between, and separating, the Earth and the Moon. Traditional concept Building on Empedocles's vision of the world as a four-level cake of stacked fundamental elements - earth, water, air and fire - with fire at the top, Aristotle saw the sublunary world as surmounted by the sphere of fire. Aristotle's conception became prevalent in the Hellenic world, and was given a distance scale by Ptolemy: “taking the radius of the spherical surface of the Earth and the water as the unit, the radius of the spherical sphere which surrounds the air and fire is 33, the radius of the lunar sphere is 64....”. The Middle Ages broadly inherited the concept of the four elements of earth, water, air and fire arranged in concentric spheres about the earth as centre: as the purest of the four elements, fire - and the sphere of fire - stood highest in the ascending sequence of the ''scala naturae'', and closest to the s ...
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Greek Astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the Ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the language of scholarship throughout the Hellenistic world following the conquests of Alexander. This phase of Greek astronomy is also known as Hellenistic astronomy, while the pre-Hellenistic phase is known as Classical Greek astronomy. During the Hellenistic and Roman periods, much of the Greek and non-Greek astronomers working in the Greek tradition studied at the Museum and the Library of Alexandria in Ptolemaic Egypt. The development of astronomy by the Greek and notably Hellenistic astronomers is considered to be a major phase in the history of astronomy. Greek astronomy is characterized by seeking a geometrical model for celestial phenomena. Most of the names of the stars, planets, ...
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Air (classical Element)
Air is one of the four classical elements along with water, earth and fire in ancient Greek philosophy and in Western alchemy. Greek and Roman tradition According to Plato, it is associated with the octahedron; air is considered to be both hot and wet. The ancient Greeks used two words for air: ''aer'' meant the dim lower atmosphere, and '' aether'' meant the bright upper atmosphere above the clouds. Plato, for instance writes that "So it is with air: there is the brightest variety which we call ''aether'', the muddiest which we call mist and darkness, and other kinds for which we have no name...." Among the early Greek Pre-Socratic philosophers, Anaximenes (mid-6th century BCE) named air as the ''arche''. A similar belief was attributed by some ancient sources to Diogenes Apolloniates (late 5th century BCE), who also linked air with intelligence and soul (''psyche''), but other sources claim that his ''arche'' was a substance between air and fire. Aristophanes parodied such t ...
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Star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night, but their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), 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 star formation, begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Its stellar ...
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Fire (classical Element)
Fire is one of the four classical elements along with earth, water and air in ancient Greek philosophy and science. Fire is considered to be both hot and dry and, according to Plato, is associated with the tetrahedron. Greek and Roman tradition Fire is one of the four classical elements in ancient Greek philosophy and science. It was commonly associated with the qualities of energy, assertiveness, and passion. In one Greek myth, Prometheus stole ''fire'' from the gods to protect the otherwise helpless humans, but was punished for this charity. Fire was one of many '' archai'' proposed by the pre-Socratics, most of whom sought to reduce the cosmos, or its creation, to a single substance. Heraclitus considered ''fire'' to be the most fundamental of all elements. He believed fire gave rise to the other three elements: "All things are an interchange for fire, and fire for all things, just like goods for gold and gold for goods." Diels-Kranz B90 (Freeman 9481970p. 45. He had a repu ...
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Aristotelian Physics
Aristotelian physics is the form of natural science described in the works of the Greek philosopher Aristotle (384–322 BC). In his work ''Physics'', Aristotle intended to establish general principles of change that govern all natural bodies, both living and inanimate, celestial and terrestrialincluding all motion (change with respect to place), quantitative change (change with respect to size or number), qualitative change, and substantial change (" coming to be" oming into existence, 'generation'">existence.html" ;"title="oming into existence">oming into existence, 'generation'or "passing away" [no longer existing, 'corruption']). To Aristotle, 'physics' was a broad field that included subjects that would now be called the philosophy of mind, sensory experience, memory, anatomy and biology. It constitutes the foundation of the thought underlying many of his works. Key concepts of Aristotelian physics include the structuring of the cosmos into concentric spheres, with the Ear ...
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Water (classical Element)
Water is one of the classical elements in ancient Greek philosophy along with air, earth and fire, in the Asian Indian system ''Panchamahabhuta'', and in the Chinese cosmological and physiological system ''Wu Xing''. In contemporary esoteric traditions, it is commonly associated with the qualities of emotion and intuition. Greek and Roman tradition Water was one of many ''archai'' proposed by the Pre-socratics, most of whom tried to reduce all things to a single substance. However, Empedocles of Acragas (c. 495 – c. 435 BC) selected four archai for his four roots: air, fire, water and earth. Empedocles roots became the four classical elements of Greek philosophy. Plato (427–347 BC) took over the four elements of Empedocles. In the Timaeus, his major cosmological dialogue, the Platonic solid associated with water is the icosahedron which is formed from twenty equilateral triangles. This makes water the element with the greatest number of sides, which Plato regarded as appropri ...
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Cosmos
The cosmos (, ) is another name for the Universe. Using the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity. The cosmos, and understandings of the reasons for its existence and significance, are studied in cosmologya broad discipline covering scientific, religious or philosophical aspects of the cosmos and its nature. Religious and philosophical approaches may include the cosmos among spiritual entities or other matters deemed to exist outside the physical universe. Etymology The philosopher Pythagoras first used the term ''kosmos'' ( grc, κόσμος, Latinized ''kósmos'') for the order of the universe. Greek κόσμος "order, good order, orderly arrangement" is a word with several main senses rooted in those notions. The verb κοσμεῖν (''κοσμεῖν'') meant generally "to dispose, prepare", but especially "to order and arrange (troops for battle), to set (an army) in array"; also "to establish (a government or regime) ...
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Lucan
Marcus Annaeus Lucanus (3 November 39 AD – 30 April 65 AD), better known in English as Lucan (), was a Roman poet, born in Corduba (modern-day Córdoba), in Hispania Baetica. He is regarded as one of the outstanding figures of the Imperial Latin period, known in particular for his epic ''Pharsalia''. His youth and speed of composition set him apart from other poets. Life Three brief ancient accounts allow for the reconstruction of a modest biography – the earliest attributed to Suetonius, another to an otherwise unknown Vacca, and the third anonymous and undated – along with references in Martial, Cassius Dio, Tacitus's ''Annals'', and one of Statius's ''Silvae''. Lucan was the son of Marcus Annaeus Mela and grandson of Seneca the Elder; he grew up under the tutelage of his uncle Seneca the Younger. Born into a wealthy family, he studied rhetoric at Athens and was probably provided with a philosophical and Stoic education by his uncle. His wife was Polla Argentaria, ...
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Unmoved Mover
The unmoved mover ( grc, ὃ οὐ κινούμενον κινεῖ, ho ou kinoúmenon kineî, that which moves without being moved) or prime mover ( la, primum movens) is a concept advanced by Aristotle as a primary cause (or first uncaused cause) or " mover" of all the motion in the universe. As is implicit in the name, the moves other things, but is not itself moved by any prior action. In Book 12 ( grc-gre, Λ) of his ''Metaphysics'', Aristotle describes the unmoved mover as being perfectly beautiful, indivisible, and contemplating only the perfect contemplation: self-contemplation. He equates this concept also with the active intellect. This Aristotelian concept had its roots in cosmological speculations of the earliest Greek pre-Socratic philosophers and became highly influential and widely drawn upon in medieval philosophy and theology. St. Thomas Aquinas, for example, elaborated on the unmoved mover in the . First philosophy Aristotle argues, in Book 8 of the ''Physics ...
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Geocentric
In astronomy, the geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, and planets all orbit Earth. The geocentric model was the predominant description of the cosmos in many European ancient civilizations, such as those of Aristotle in Classical Greece and Ptolemy in Roman Egypt. Two observations supported the idea that Earth was the center of the Universe: * First, from anywhere on Earth, the Sun appears to revolve around Earth once per day. While the Moon and the planets have their own motions, they also appear to revolve around Earth about once per day. The stars appeared to be fixed on a celestial sphere rotating once each day about an axis through the geographic poles of Earth. * Second, Earth seems to be unmoving from the perspective of an earthbound observer; it feels solid, stable, and stationary. ...
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