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  2. Almagest - Wikipedia

    en.wikipedia.org/wiki/Almagest

    For the Moon, Ptolemy began with Hipparchus' epicycle-on-deferent, then added a device that historians of astronomy refer to as a "crank mechanism": [26] he succeeded in creating models for the other planets, where Hipparchus had failed, by introducing a third device called the equant. Ptolemy wrote the Syntaxis as a textbook of mathematical ...

  3. Deferent and epicycle - Wikipedia

    en.wikipedia.org/wiki/Deferent_and_epicycle

    According to one school of thought in the history of astronomy, minor imperfections in the original Ptolemaic system were discovered through observations accumulated over time. It was mistakenly believed that more levels of epicycles (circles within circles) were added to the models to match more accurately the observed planetary motions.

  4. Tetrabiblos - Wikipedia

    en.wikipedia.org/wiki/Tetrabiblos

    Despite Ptolemy's prominence as a philosopher, the Dutch historian of science Eduard Jan Dijksterhuis criticizes the Tetrabiblos, stating that "it only remain puzzling that the very writer of the Almagest, who had taught how to develop astronomy from accurate observations and mathematical constructions, could put together such a system of ...

  5. History of astronomy - Wikipedia

    en.wikipedia.org/wiki/History_of_astronomy

    The history of astronomy focuses on the ... Astronomy was the first science to have a ... of mathematics and astronomy. Among the discoveries are: ...

  6. Geocentric model - Wikipedia

    en.wikipedia.org/wiki/Geocentric_model

    The struggle, so violent in the early days of science, between the views of Ptolemy and Copernicus would then be quite meaningless. Either CS could be used with equal justification. The two sentences, 'the sun is at rest and the Earth moves', or 'the sun moves and the Earth is at rest', would simply mean two different conventions concerning two ...

  7. Equant - Wikipedia

    en.wikipedia.org/wiki/Equant

    The basic elements of Ptolemaic astronomy, showing a planet on an epicycle (smaller dashed circle), a deferent (larger dashed circle), the eccentric (×) and an equant (•). Equant (or punctum aequans) is a mathematical concept developed by Claudius Ptolemy in the 2nd century AD to account for the observed motion of the planets. The equant is ...

  8. History of longitude - Wikipedia

    en.wikipedia.org/wiki/History_of_longitude

    Ptolemy's map of the Mediterranean superimposed on a modern map, with Greenwich as the reference longitude. Ptolemy, in the 2nd century AD, based his mapping system on estimated distances and directions reported by travellers. Until then, all maps had used a rectangular grid with latitude and longitude as straight lines intersecting at right ...

  9. History of geodesy - Wikipedia

    en.wikipedia.org/wiki/History_of_geodesy

    A printed map from the 15th century depicting Ptolemy's description of the Ecumene. (1482, by Nicolaus Germanus) Claudius Ptolemy (90–168 AD) lived in Alexandria, the centre of scholarship in the 2nd century. In the Almagest, which remained the standard work of astronomy for 1,400 years, he advanced many arguments for the spherical nature of ...