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For the Moon, Ptolemy began with Hipparchus' epicycle-on-deferent, then added a device that historians of astronomy refer to as a "crank mechanism": [28] 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 ...
Newton was known for his book The Crime of Claudius Ptolemy (1977). In Newton's view, Ptolemy was "the most successful fraud in the history of science". Newton claimed that Ptolemy had predominantly obtained the astronomical results described in his work The Almagest by computation, and not by the direct observations that Ptolemy described.
Ptolemy's Handy Tables (Ancient Greek: πρόχειροι κανόνες, romanized: Procheiroi kanones) is a collection of astronomical tables that second century astronomer Ptolemy created after finishing the Almagest. The Handy Tables elaborated the astronomical tables of the Almagest and included usage instructions, but left out the ...
The Canon of Kings was a dated list of kings used by ancient astronomers as a convenient means to date astronomical phenomena, such as eclipses.For a period, the Canon was preserved by the astronomer Claudius Ptolemy, and is thus known sometimes as Ptolemy's Canon.
The angular rate at which the epicycle traveled was not constant unless he measured it from another point which is now called the equant (Ptolemy did not give it a name). It was the angular rate at which the deferent moved around the point midway between the equant and the Earth (the eccentric) that was constant; the epicycle center swept out ...
Unfortunately, the system that was available in Ptolemy's time did not quite match observations, even though it was an improvement over Hipparchus' system. Most noticeably the size of a planet's retrograde loop (especially that of Mars) would be smaller, or sometimes larger, than expected, resulting in positional errors of as much as 30 degrees.
In Ptolemy's era the boundaries of the zodiac signs were close to those of the visible constellations whose names they bear, but Ptolemy demonstrates the theoretical distinction between the two frames of reference in describing the starting point of the zodiac as fixed, not to the stars, but to the mathematically calculated vernal equinox. [57]
Ptolemy (c. AD 100 – c. 170) was an Alexandrian mathematician, astronomer, geographer and astrologer. Ptolemy , Ptolemaeus or Tolomeo may also refer to: People