Ptolemy vs. Copernicus


Claudius Ptolemy (100-170 CE) was a Greek mathematician, astronomer, cartographer and writer, famous for his geocentric model of the universe and his principal work, the Geographia. His theories dominated western thought for well over a millennium, and in some religious circles, even into the nineteenth century. But in 1543, the German mathematician and astronomer, Nicolaus Copernicus, published his De revolutionibus orbium coelestium (On the revolutions of the celestial spheres). Soon after, the Magistrate of the Holy Palace, the very persuasive Giovanni Maria Tolosani, attacked the “Copernican doctrine.” In the same spirit of Thomas Aquinas, Tolosani attempted to refute the Copernican argument using reason. He wrote, “The foolishness of this book’s author is rebuked. For by a foolish effort he tried to revive the weak Pythagorean opinion, long ago deservedly destroyed, since it is expressly contrary to human reason and also opposes holy writ. From this situation, there could easily arise disagreements between Catholic expositors of holy scripture and those who might wish to adhere obstinately to this false opinion.” Then there was Francesco Ingoli, a Catholic priest, who wrote an essay to Galileo in 1616, including more than twenty arguments against Copernicus. Galileo was even ordered by Pope Paul V not to defend Copernicus, but he refused, was convicted of heresy, and placed on house arrest for the remainder of his life.


Bernardo Silvani, Jacopo Pencio, Claudius Ptolemy, Venice, 1511

Republished by Jacobus Pentius de Leucho in Venice, this is the 1511 edition of Ptolemy’s influential Geographia. Jacobus Pentius reworked Ptolemy’s projection to include the newly discovered Americas.

Typus Cosmographicus Universalis

Sebastian Munster, Johann Huttich, Hans Holbein, and Simon Gryna us, Basle, 1555

Eleven years before the publication of Copernicus’ theory of the solar system, this map shows two winged angels turning the world on its axis.

[Ptolemaic Armillary Sphere]

The Delamarche Armillary Sphere is based on Ptolemy’s model of the heavens. It depicts the great celestial rings, including the Equator, the meridian, the ecliptic, the poles, the horizon and the tropics.

The Celestial Indicator

Because most armillary spheres were meant for demonstration, rather than observation, both Copernican and Ptolemaic models were produced to demonstrate the two theories to the upper and middle class intellectuals of the enlightenment. And even in nineteenth century Europe, there were still those who preferred the Ptolemaic model.

Atlas Novus Coelestis in quo mundus spectabilis et in eodem tam errantivm quam inerrantium stellarum phoenomena notabilia, circaipsarum lumen, figuram, faciem, motum, eclipses, occulationes, transitus, magnitudines, distantias, aliaque secundum Nic. Coper

Johann Gabriel Doppelmayr, Nuremberg, 1742

Astronomy was once a very serious matter, rife with political and religious controversy. But some astronomers managed to maintain a healthy sense of humor. Johann Gabriel Doppelmayr was one of those astronomers. In this geocentric diagram, the planets are represented by cherubs on swings. As Doppelmayr explains, if the Earth is the center of the universe, it must push the other planets away from itself whenever they get too close. This creates a series of looping patterns around the Earth (pictured again on the next page of the atlas), rather than the circular patterns used by Ptolemaic astronomers.