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Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform speeds. The Copernican model departed from the Ptolemaic system that prevailed in Western culture for centuries, placing Earth at the center of the Universe, and is often regarded as the launching point to modern astronomy and the Scientific Revolution. Copernicus was aware that the ancient Greek Aristarchus had already proposed a heliocentric theory, and cited him as a proponent of it in a reference that was deleted before publication, but there is no evidence that Copernicus had knowledge of, or access to, the specific details of Aristarchus' theory.〔Gingerich, O. ("Did Copernicus Owe a Debt to Aristarchus?" ) Journal for the History of Astronomy, Vol.16, NO.1/FEB, pp.37, 39, 1985〕 Although he had circulated an outline of his own heliocentric theory to colleagues sometime before 1514, he did not decide to publish it until he was urged to do so late in his life by his pupil Rheticus. Copernicus's challenge was to present a practical alternative to the Ptolemaic model by more elegantly and accurately determining the length of a solar year while preserving the metaphysical implications of a mathematically ordered cosmos. Thus his heliocentric model retained several of the Ptolemaic elements causing the inaccuracies, such as the planets' circular orbits, epicycles, and uniform speeds,〔 while at the same time re-introducing such innovations as, :: *Earth is one of several planets revolving around a stationary Sun in a determined order :: *Earth has three motions: daily rotation, annual revolution, and annual tilting of its axis :: *Retrograde motion of the planets is explained by Earth's motion :: *Distance from Earth to the Sun is small compared to the distance to the stars. ==Earlier theories with the Earth in motion== (詳細はPhilolaus (4th century BCE) was one of the first to hypothesize movement of the Earth, probably inspired by Pythagoras' theories about a spherical, moving globe. Aristarchus of Samos in the 3rd century BCE had developed some theories of Heraclides Ponticus (speaking of a revolution by Earth on its axis) to propose what was, so far as is known, the first serious model of a heliocentric solar system. Though his original text has been lost, a reference in Archimedes' book ''The Sand Reckoner'' (''Archimedis Syracusani Arenarius & Dimensio Circuli'') describes a work by Aristarchus in which he advanced the heliocentric model. Archimedes wrote: It is a common idea that the heliocentric view was rejected by the contemporaries of Aristarchus. This is due to Gilles Ménage's translation of a passage from Plutarch's ''On the Apparent Face in the Orb of the Moon''. Plutarch reported that Cleanthes (a contemporary of Aristarchus and head of the Stoics) as a worshipper of the Sun and opponent to the heliocentric model, was jokingly told by Aristarchus that he should be charged with impiety. Gilles Ménage, shortly after the trials of Galileo and Giordano Bruno, amended an accusative (identifying the object of the verb) with a nominative (the subject of the sentence), and vice versa, so that the impiety accusation fell over the heliocentric sustainer. The resulting misconception of an isolated and persecuted Aristarchus is still transmitted today.〔Lucio Russo, Silvio M. Medaglia, Sulla presunta accusa di empietà ad Aristarco di Samo, in "Quaderni urbinati di cultura classica", n.s. 53 (82) (1996), pp. 113–121〕〔Lucio Russo, The forgotten revolution, Springer (2004)〕 Ibn al-Haytham, Abu-Rayhan Biruni, Abu Said Sinjari, Najm al-Dīn al-Qazwīnī al-Kātibī, and Qutb al-Din al-Shirazi discussed astronomy and logic flaws in the Ptolemaic system, but did not propose a heliocentric system. Copernicus cited Aristarchus and Philolaus in an early manuscript of his book which survives, stating: "Philolaus believed in the mobility of the earth, and some even say that Aristarchus of Samos was of that opinion."〔Gingerich, O. "Did Copernicus Owe a Debt to Aristarchus?" Journal for the History of Astronomy, Vol.16, NO.1/FEB, P. 37, 1985〕 For reasons unknown (although possibly out of reluctance to quote pre-Christian sources), he did not include this passage in the publication of his book. Inspiration came to Copernicus not from observation of the planets, but from reading two authors. In Cicero he found an account of the theory of Hicetas. Plutarch provided an account of the Pythagoreans Heraclides Ponticus, Philolaus, and Ecphantes. These authors had proposed a moving Earth, which did not, however, revolve around a central sun. When Copernicus' book was published, it contained an unauthorized preface by the Lutheran theologian Andreas Osiander. This cleric stated that Copernicus wrote his heliocentric account of the Earth's movement as a mere mathematical hypothesis, not as an account that contained truth or even probability. Since Copernicus' hypothesis was believed to contradict the Old Testament account of the Sun's movement around the Earth (Joshua 10:12-13), this was apparently written to soften any religious backlash against the book. However, there is no evidence that Copernicus himself considered the heliocentric model as merely mathematically convenient, separate from reality. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Copernican heliocentrism」の詳細全文を読む スポンサード リンク
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