This and other fears of the solar system have disappeared gradually, first, with the Ptolemaic system and its built-in concept of periodicity and then, more firmly, with the Newtonian innovation of an universal force that could account quantitatively for both terrestial and celestial motions.

Bluntly, there never was a Ptolemaic system of astronomy.

But none of this has prevented scientists, philosophers, and even historians of science, from speaking of the Ptolemaic system, in contrast to the Copernican.

Thus, Margenau remarks: `` A large number of unrelated epicycles was needed to explain the observations, but otherwise the ( Ptolemaic ) system served well and with quantitative precision.

Despite their embrace of the principle of rectilinear inertia and the recognition of the kinematical relativity of apparent motion ( which underlies whether the Ptolemaic or the Copernican system is correct ), natural philosophers of the seventeenth century continued to consider true motion and rest as physically separate descriptors of an individual body.

Hermann Bondi named the principle after Copernicus in the mid-20th century, although the principle itself dates back to the 16th-17th century paradigm shift away from the Ptolemaic system, which placed Earth at the center of the Universe.

More importantly, the incontrovertible discovery of celestial bodies orbiting something other than the Earth dealt a serious blow to the then-accepted Ptolemaic world system, or the geocentric theory in which everything orbits around the Earth.

More importantly, the discovery of celestial bodies orbiting something other than the Earth dealt a blow to the then-accepted Ptolemaic world system, which held that the Earth was at the center of the universe and all other celestial bodies revolved around it.

The gradual chipping away of the Ptolemaic system paved the way for the revolutionary idea that the Earth actually orbited the Sun ( heliocentricism ).

The Ptolemaic system had been accepted for more than 1, 400 years.

Under the instruction of Michael Maestlin, Tübingen's professor of mathematics from 1583 to 1631, he learned both the Ptolemaic system and the Copernican system of planetary motion.

There is no doubt that Copernicus ' " De Revolutionibus " seeks to advance a sun-centered system, but in this book he had to resort to Ptolemaic devices ( viz., epicycles and eccentric circles ) in order to explain the change in planets ' orbital speed.

" Therefore, although the thesis of the " Mysterium Cosmographicum " was in error, modern astronomy owes much to this work " since it represents the first step in cleansing the Copernican system of the remnants of the Ptolemaic theory still clinging to it.

In the Galileo affair, the acceptance, from 1616 to 1757, of the Greek geocentric model ( Ptolemaic system ) by the Roman Catholic Church, and its consequent opposition to heliocentrism, was first called into question by the Catholic cleric Copernicus, and subsequently disproved conclusively by Galileo, who was persecuted for his minority view.

His observations of the moons of Jupiter, the phases of Venus, the spots on the sun, and mountains on the moon all helped to discredit the Aristotelian philosophy and the Ptolemaic theory of the solar system.

As an astronomer, Tycho worked to combine what he saw as the geometrical benefits of the Copernican system with the philosophical benefits of the Ptolemaic system into his own model of the universe, the Tychonic system.

It is also known from Livy that the mines and the forests were leased for a fixed sum under Philip V, and it appears that the same happened under the Argaead dynasty: from here possibly comes the leasing system that was used in Ptolemaic Egypt.

* 1610 – Galileo Galilei discovers Callisto, Europa, Ganymede, and Io, sees Saturn's planetary rings ( but does not recognize that they are rings ), and observes the phases of Venus, disproving the Ptolemaic system, though not the geocentric model

Figure of the heavenly bodies — An illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho, 1568 ( Bibliothèque Nationale, Paris )

In astronomy, the geocentric model ( also known as geocentrism, or the Ptolemaic system ), is the theory that the Earth is the orbital center for all celestial bodies.

In the Ptolemaic system of astronomy, the epicycle ( literally: on the circle in Greek ) was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets.

* The Ptolemaic model of planetary motion: Based on the geometrical model of Eudoxus of Cnidus, Ptolemy's Almagest, demonstrated that calculations could compute the exact positions of the Sun, Moon, stars, and planets in the future and in the past, and showed how these computational models were derived from astronomical observations.

The Eudoxan planetary model, on which the Aristotelian and Ptolemaic models were based, was the first geometric explanation for the " wandering " of the classical planets.

Despite the fact that the Ptolemaic system is considered geocentric, the planets ' motion was not thought to be actually centered on the Earth.

In the Ptolemaic system the models for each of the planets were different and so it was with Copernicus ' initial models.

In doing so, Copernicus moved heliocentrism from philosophical speculation to predictive geometrical astronomy — in reality it did not predict the planets ' positions any better than the Ptolemaic system.

Tycho Brahe, arguably the most accomplished astronomer of his time, advocated against Copernicus's heliocentric system and for an alternative to the Ptolemaic geocentric system: a geo-heliocentric system now known as the Tychonic system in which the five then known planets orbit the sun, while the sun and the moon orbit the earth.

In the Copernican system the Earth and other planets orbit the Sun, while in the Ptolemaic system everything in the Universe circles around the Earth.

On the other hand, because of the intersecting deferents of Mars and the Sun ( see diagram ), it went against the Ptolemaic and Aristotelian notion that the planets were placed within nested spheres.

After Tycho's death, Johannes Kepler used the observations of Tycho himself to demonstrate that the orbits of the planets are ellipses and not circles, creating the modified Copernican system that ultimately displaced both the Tychonic and Ptolemaic systems.

Al-Zarqālī wrote two works on the construction of an instrument ( an equatorium ) for computing the position of the planets using diagrams of the Ptolemaic model.

To Riccioli the question was not between the geocentric world system of Ptolemy and the heliocentric world system of Copernicus, for the telescope had unseated the Ptolemaic system ; it was between the geo-heliocentric world system developed by Tycho Brahe in the 1570s ( in which the sun, moon, and stars circle an immobile Earth, while the planets circle the sun – sometimes called a " geo-heliocentric " or " hybrid " system ) and that of Copernicus.

At this time, Copernicus anticipated that he could reconcile the motion of the Earth with the perceived motions of the planets easily, with fewer motions than were necessary in the Alfonsine Tables, the version of the Ptolemaic system current at the time.

His most important astronomical treatise was the ( The Final Quest Concerning the Rectification of Principles ), in which he drastically reformed the Ptolemaic models of the Sun, Moon, and planets.

The orbits of planets in the once popular geocentric Ptolemaic system are epitrochoids.

A total of twenty Ptolemaic constellations are directly continued from the Ancient Near East.

Two other fragmentary copies of the same decree were discovered later, and several similar Egyptian bilingual or trilingual inscriptions are now known, including two slightly earlier Ptolemaic decrees ( the Decree of Canopus in 238 BC, and the Memphis decree of Ptolemy IV, ca.

The earliest attempts to write the Egyptian language using the Greek alphabet are Greek transcriptions of Egyptian proper names, most of which date to the Ptolemaic period.

Opposite Elephantine, on the east bank at Aswan, Khnum, Satis and Anukis are shown on a chapel wall dating to the Ptolemaic time.

They are, however, of the Ptolemaic age, with the exception of a doorway of sandstone, built into a wall of brick.

The traditional major aspects are sometimes called Ptolemaic aspects since they were defined and used by Ptolemy in the 1st Century, AD.

The major aspects and the three border aspects are together called the Ptolemaic aspects.

* Observations that are incompatible with the Ptolemaic model: the phases of Venus, for instance, which simply couldn't happen, or the apparent motions of sunspots, which could only be explained in the Ptolemaic or Tychonic systems as resulting from an implausibly complicated precession of the Sun's axis of rotation.

These motions are similar to the deferent and epicycle, respectively, of the Ptolemaic model of the solar system.

There have been many people named Ptolemy or Ptolemaeus, the most famous of which are the Greek-Egyptian astronomer Claudius Ptolemaeus and the Macedonian founder and ruler of the Ptolemaic Kingdom in Egypt, Ptolemy I Soter.

Ptolemaic graphs, are exactly the graphs that are both chordal and distance hereditary.

In the vicinity of the city, there are a great number of ancient cemeteries ( like Kom Ishu, Kom El-Farag, Sidi Ghazi, Kom Defshu, Kom El-Terfayeh, and Tell El-Kanaies ), where remains of pottery and some rocks from the Ptolemaic Era can be found.

The legendary Alexander material originated as early as the time of the Ptolemaic dynasty ( 305 BC to 30 BC ) and its unknown authors are sometimes referred to as the Pseudo-Callisthenes ( not to be confused with Callisthenes of Olynthus, who was Alexander's official historian ).

There are also Roman and pharaonic Mammisi ( birth houses ), ruins of a Coptic church and a small chapel dedicated to Isis, dating to the Roman or the Ptolemaic epoch.

Depictions of Cleopatra VI which appear on temple walls are good examples Ptolemaic Egyptian art.

As the Astronomia nova proper starts, Kepler demonstrates that the Tychonic, Ptolemaic, and Copernican systems are indistinguishable on the basis of observations alone.

Greek Christianity had of necessity a pronounced Oriental character ; Ptolemaic Egypt and Seleucid Syria are the real birthplaces of the Graeco-Oriental church and Byzantine civilization in general.