The Ptolemaic System

The System	Terrestrial Ball
The Talmud	Money in the Bank
Poets

The System

The description of the universe systematized by Claudio Ptolemy is science, not mythology; it has high predictive value. If you want to know when there will be an eclipse of the sun or moon, or where Venus will be in the night sky six years from this date, Ptolemy's system works as well as Copernicus'. The heavens are proposed to move spherically because, among other things:

“In a word, whatever figure other than the spherical be assumed for the movement of the heavens, there must be unequal linear distances from the earth to parts of the heavens, wherever or however the earth be situated, so that the magnitudes and angular distances of the stars with respect to each other would appear unequal to the same people within each revolution, now larger now smaller. But this is not observed to happen.”
(Ptolemy, Almagest, Book 1, 3. That the Heavens Move Spherically).

Andreas Cellarius, Map of the Ptolemaic System

The earth in this system is round, though some people insist otherwise. Ptolemy thought the earth was spherical because, among other reasons:

“Now, that also the earth taken as a whole is sensibly spherical, we could most likely think out in this way. For again it is possible to see that the sun and moon and the other stars do not rise and set at the same time for every observer on the earth, but always earlier for those living towards the orient and later for those living towards the occident. For we find that the phenomena of eclipses taking place at the same time, especially those of the moon, are not recorded at the same hours for everyone -- that is, relatively to equal intervals of time from noon; but we always find later hours recorded for observers towards the orient than for those towards the occident. And since the differences in the hours is found to be proportional to the distances between the places, one would reasonably suppose the surface of the earth spherical, with the result that the general uniformity of curvature would assure every part's covering those following it proportionately. But this would not happen if the figure were any other. . .”
(Ptolemy, Almagest, Book 1, 4. That the Earth, Taken as a Whole, is Sensibly Spherical).

This seventeenth century artist has taken the liberty of enlarging the earth for clarity. In Ptolemy's system, the earth is a point by comparison with the sphere of the fixed stars:

“Now, that the earth has sensibly the ratio of a point to its distance from the sphere of the so-called fixed stars gets great support from the fact that in all parts of the earth the sizes and angular distances of the stars at the same times appear everywhere equal and alike, for the observations of the same stars in the different latitudes are not found to differ in the least.
“Moreover, this must be added: that sundials placed in any part of the earth and the centers of armillary spheres can play the role of the earth's true center for the sightings and the rotations of the shadows, as much in conformity with the hypotheses of the appearances as if they were at the true midpoint of the earth.”
(Ptolemy, Almagest, Book 1, 6. That the Earth Has the Ratio of a Point to the Heavens).

The system is geocentric. While we envision earth hurtling through space, while turning about on its axis, in Ptolemy's system, everything else moves, not the earth. Ptolemy had heard speculation to the contrary:

“Now some people, although they have nothing to oppose to these arguments, agree on something, as they think, more plausible. And it seems to them there is nothing against their supposing, for instance, the heavens immobile and the earth as turning on the same axis from west to east very nearly one revolution a day. . .for us to grant these things, they would have to admit that the earth's turning is the swiftest of absolutely all the movements about it because of its making so great a revolution in a short time, so that all those things that were not at rest on the earth would seem to have a movement contrary to it, and never would a cloud be seen to move toward the east nor anything else that flew or was thrown into the air. For the earth would always outstrip them in its eastward motion, so that all other bodies would seem to be left behind and to move towards the west.”
(Ptolemy, Almagest, Book 1, 7. That the Earth Does Not in any Way Move Locally).

Ptolemy's contemporaries could not fathom why a moving earth would not leave behind it a garbage stream like the wake of a negligent cruise liner, a trail of dropped items like the clues left by a fleeing criminal. Why would your dropped keys, not tethered to your hand nor to the ground, not fall somewhere other than directly below where you dropped them, as they are always observed to do, if the earth beneath your feet has moved in the mean time? It took the genius of Galileo Galilei to explain this, thus making the world safe for heliocentrism.

Aristotle
On the Heavens

Terrestrial Ball

Ptolemy's system was originated not by himself but by earlier astronomers. Its contemporary acceptance was not universal, but the widespread belief that has somehow established itself that everyone prior to Christopher Columbus thought the earth was flat is baseless. When the hymn-writer sings,

"Let every kindred, every tribe,
On this terrestrial ball,
To Him all majesty ascribe,
And crown Him Lord of all;
To Him all majesty ascribe,
And crown Him Lord of all!
(All Hail the Power of Jesus' Name)

...it is foolish to insist the question of flat-earthism remains open. And writers in antiquity also called the earth a globe or an orb:

"Military discipline jealously conserved won the leadership of Italy for Roman empire, bestowed rule over many cities, great kings, mighty nations...made it from its origin in Romulus' little cottage into the summit of the entire globe [terrarum orbis]." (Valerius Maximus, 'Memorable Doings and Sayings,' Book II.8).

"For he wisely realized that increase for Roman empire was to be asked for in the days when triumphs were sought on the near side of the seventh milestone, but for a people that possessed the greater part of the whole globe [terrarum orbis] it would be greedy to ask for more and abundantly fortunate if they lost nothing of what was already theirs." (Valerius Maximus, 'Memorable Doings and Sayings,' Book IV.1).

"The magnanimous monarch, who had already embraced the entire globe [terrarum orbem] by his victories or expectations, in so few words shared himself with him companion." (Valerius Maximus, 'Memorable Doings and Sayings,' Book IV.7).

"The signal clemency of the divine leader kept this father safe, but who would not think his daring more than human in that he did not yield to one to whom the whole world [terrarum orbis] succumbed?" (Valerius Maximus, 'Memorable Doings and Sayings,' Book V.7).

Since this language is boiler-plate, it comes as no surprise when Eusebius puts the phrase in the mouth of the Emperor Constantine:

"The stars move in no uncertain orbits round this terrestrial globe." (Eusebius, The Life of Constantine, Book 2, Chapter 58).

Talmud

Did the Jews agree with the pagans on the rotundity of the earth? One answer is found in the Talmud, which discusses statuary. Is it an ornamentation to a city, or idolatry? According to the Rabbis, if a statue, of an emperor, say, holds a ball in his hand, this suggests he rules the whole world, the prerogative of God:

"...Rabbah said: There is difference of opinion [with regard to statues] in cities; but as for those in villages all agree that they are prohibited.

"BUT THE SAGES DECLARE, [AN IMAGE] IS NOT PROHIBITED etc. [It is prohibited when holding] a staff, because [the implication is] that it rules the whole world as with a staff. [...] [It is prohibited when holding] an orb, because [the implication is] that it grasps the whole world as though it were a ball."
(Babylonian Talmud, Abodah Zara 41a).

But why would holding a ball convey this message, if it were thought the earth is flat?

Money in the Bank

A round object turns up on Roman coins, such as this one depicting the Emperor Caracalla holding the world in his hand:

Poets

Some people are willing to concede that the astronomers of antiquity realized the earth was round, as indeed cannot be denied. They allege, however, that most people did not know this. While there are dissenters throughout the period, in fact most people had good reason to know this. A rotund earth turns up in popular poetry, like Virgil's Georgics:

"As our globe rises steep to Scythia and the Riphaean crags, so it slopes downward to Libya's southland. One pole is ever high above us, while the other, beneath our feet, is seen of black Styx and the shades infernal. . .There, men say, is either the silence of lifeless night, and gloom ever thickening beneath night's pall; or else Dawn returns from us and brings them back the day, and when on us the rising Sun first breathes with panting steeds, there glowing Vesper is kindling his evening rays." (Virgil, Georgics, Georgic 1).

What is the music of the spheres?:

Cicero
Scipio's Dream