# Ptolemaic

## Definitions

• WordNet 3.6
• adj Ptolemaic of or relating to the geocentric Ptolemaic system "in the Ptolemaic system of planetary motion the earth is fixed as the center of the universe with the sun and moon and planets revolving around it"
• adj Ptolemaic of or relating to the astronomer Ptolemy
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Webster's Revised Unabridged Dictionary
• a Ptolemaic Of or pertaining to Ptolemy, the geographer and astronomer.
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Century Dictionary and Cyclopedia
• Ptolemaic Of or pertaining to Ptolemy; relating to one or all of the line of Ptolemies, rulers of Egypt from the end of the fourth to the first century b. c.
• Ptolemaic relating to the Alexandrian geographer and astronomer Ptolemy (see below).
• Ptolemaic He represented the deferent by the circle, thus giving it a breadth too great. This circle remained in an eccentric position, whence it was called the eccentric, as well as the deferent and the orbit.
• Ptolemaic Instead of supposing the moving radius, TD, to describe equal areas in equal times, he drew a line to D, the attachment of the epicycle with the deferent from E, really corresponding to the empty focus of the ellipse, but called by him the center of the equant, and be supposed this line ED to turn with an equable motion so as to describe equal angles in equal times. This made an observable error only in the case of Mars. It made a tolerable approximation to the elliptic motion, which excited the admiration of Kepler, and it shows that Ptolemy aimed at something much better than a mere harmonic analysis of the motions of the planets.
• Ptolemaic He not only made the epicycle circular, but he placed its center upon the deferent, thus virtually neglecting the eccentricity as well as the ellipticity of the earth's orbit in its effects on the apparent places of the exterior planets.
• Ptolemaic He made the planet revolve in its epicycle so as to describe in equal times equal arcs measured from the perigee of the epicycle, as if the earth's motion were affected by the eccentricity of the orbit of the other planet.
• Ptolemaic And he made the planet come to the perigee of its epicycle when it was just opposite the mean place of the sun, instead of the true place. Other still more serious falsities affected his theories of the inferior planets and of the moon. Yet, notwithstanding all these errors, Ptolemy's theory satisfied pretty closely, in the cases of all the planets except Mercury and the moon, such observations as could be made in his time. In his phrase, it “saved appearances.” The Ptolemaic theory continued in vogue until Copernicus (in 1543) explained the relations between the motions of the planets and that of the sun, and thus supplied a method for determining the relative magnitudes of the different planetary orbits. But the system of Copernicus did not in itself represent the phenomena any better than that of Ptolemy; and it was not until the great work of Kepler on the motions of Mars, published in 1609, that the real truth was known. The Almagest remains, however, a model of scientific investigation, most admirable for the genius with which it manages not only the astronomical problems attacked, but also those of pure mathematics.
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Chambers's Twentieth Century Dictionary
• adj Ptolemaic tol-e-mā′ik pertaining to the race of Egyptian kings called the Ptolemies: pertaining to Ptolemy the astronomer (of the 2d century)—also Ptolemæ′an
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## Usage

### In literature:

A HISTORY OF EGYPT UNDER THE PTOLEMAIC DYNASTY.
"Werwolves" by Elliott O'Donnell
He was the second monarch of the Ptolemaic line.
"Pyrrhus" by Jacob Abbott
The Ptolemaic scheme was better suited to human needs.
"Appearances" by Goldsworthy Lowes Dickinson
MAHAFFY, J. P. History of Egypt under the Ptolemaic Dynasty, p. 56 ff.
"Introduction to the History of Religions" by Crawford Howell Toy
Ptolemaic system of astronomy, 148.
"History of Education" by Levi Seeley
It would be as rational to hold that our best almanacs reveal the Ptolemaic astronomy.
"The Testimony of the Rocks" by Hugh Miller
Even at the present day, we habitually use the Ptolemaic phraseology.
"The Astronomy of the Bible" by E. Walter Maunder
In 1632 appeared his "Dialogues" on the Ptolemaic and Copernican systems.
"Pioneers of Science" by Oliver Lodge
The Ptolemaic princesses seem, as a whole, to have been superior to the men.
"Greek Women" by Mitchell Carroll
In the Ptolemaic period it was used for desert transport and gradually became common.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 1" by Various
In Germany, during the 15th century, a brilliant attempt was made to patch up the flaws in Ptolemaic doctrine.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 7" by Various
EGYPT UNDER THE PTOLEMAIC DYNASTY.
"Here and Hereafter" by Barry Pain
Under Ptolemaic rule Cyprus has little history.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8" by Various
Bacon died a believer in the Ptolemaic system of astronomy.
"The Works of Robert G. Ingersoll, Vol. 6 (of 12) Dresden Edition--Discussions" by Robert G. Ingersoll
The Ptolemaic system was too strongly intrenched, and the motions of all the bodies in the sky were too well represented by it.
"Astronomy" by David Todd
From the Ptolemaic kingdom Hellenism early travelled up the Nile into Ethiopia.
"Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2" by Various
This was, in fact, a very common name among the princesses of the Ptolemaic line.
"History of Cleopatra, Queen of Egypt" by Jacob Abbott
A second developed a trigonometry of sines to replace the Ptolemaic trigonometry of chords.
"An Introduction to the History of Science" by Walter Libby
They are found lying in the utmost confusion; in date they range from the XIIth Dynasty to the Ptolemaic period.
"Encyclopaedia Britannica, 11th Edition, Volume 15, Slice 6" by Various
Few vestiges remain of the architectural splendor of the Ptolemaic dynasty.
"The Mediterranean" by T. G. (Thomas Gray) Bonney, E. A. R. Ball, H. D. Traill, Grant Allen, and Arthur Griffiths
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### In news:

Photo provided by Ptolemaic Productions.
Although Cleopatra 's Roman enemy, Octavian, tried to destroy all statues of her after her death, this Ptolemaic sculpture has her look.
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### In science:

To me such arguments sound a bit like epicycles in Ptolemaic astronomy: some of our colleagues are trying to rescue a theory in trouble.
Theory Summary: International Symposium on Multiparticle Dynamics 2008
Galilei, G. (1632), “Dialogue concerning the two chief world systems: The Ptolemaic and the Copernican,” Gio Pertista Landini.
A Wikipedia Literature Review
Ptolemaic and Copernican theories) is provided by the theory of the Moon.
Quasi periodic motions from Hipparchus to Kolmogorov
Namely we check that also the motions of the Ptolemaic lunar theories, as actually al l quasi periodic motions, can be interpreted in terms of epicycles.
Quasi periodic motions from Hipparchus to Kolmogorov
We can say that the experimental data agree within a third order error in the eccentricity with the hypothesis of an el liptical motion and with a time law based on the area law: this, within a second order error in the eccentricity, coincides with the Ptolemaic law of the equant.
Quasi periodic motions from Hipparchus to Kolmogorov
Dreyer,: A history of astronomy, Dover, 1953. 4 For a simple introduction to the Ptolemaic system see: Neugebauer, O.: The exact sciences in antiquity, Dover, 1969.
Quasi periodic motions from Hipparchus to Kolmogorov
His equant was set, to save the phenomena, a little closer to the center (with respect to the Ptolemaic equant point) at distance e′a from the center C of the deferent rather than at distance ea.
Quasi periodic motions from Hipparchus to Kolmogorov
This very Ptolemaic interpretation of Kepler’s ellipse, formally pointed out to Kepler by Fabricius, see3 p. 402403 (but it is simply impossible that Kepler had not known it immediately), is “ruined” by the very original Kepler law ρ ˙ξ = const which implies that ˙ξ is not constant.
Quasi periodic motions from Hipparchus to Kolmogorov
The law ρ ˙ξ = const, i.e. the area law, is completely out of the Copernican views and it recalls to mind the mysterious Ptolemaic lunar constructions for which we have apparently no clue on how they were derived.
Quasi periodic motions from Hipparchus to Kolmogorov
Although some comments on this would have helped a lot the readers, it seems unlikely that he did not notice that ρ ˙ξ is not proportional to the area velocity unless the motion is on an ellipse with eccentric anomaly ξ, particularly after Fabricius’ comments on the Ptolemaic version of the ellipse.
Quasi periodic motions from Hipparchus to Kolmogorov
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