Ptolemy with an amillary sphere

Ptolemy: Claudius Ptolemy (circa 100--175 CE)

The greatest mathematical astronomer of the ancient world. His book the Almagest is the ancient classic of astronomy:

The original title was something like Mathematical Treatise. Almagest is a Latinization of an Arabization of the Greek expression ``the Greatest.'' How could Ptolemy have missed heliocentrism: I'd just like to kick the guy sometimes: he'd probably want to kick himself.


  1. Ptolemy Bill Arnett
  2. Ptolemy The Galileo Project's page on the Ptolmaic System
  3. Ptolemy iconography site Robert Derome, University de Quebec a Montreal. Extremely useful site, except that no mention of the status of the on-web image is given: copyrighted, public domain, unknown?
  4. Ptolemy The SEDS webpage on him.
  5. Ptolemy The University of St. Andrews Biographies of Mathematicians and Astronomers.
  6. Ptolemy Wikipedia.
  7. G.J. Toomer's translation of Ptolemy's Almagest Just the reference.

Many of the images are now broken links. I've come to the conclusion that without some clear statement of permission to use or of public domain status, I've no clear right to show those images. The historical originals are uncopyrighted, of course, but the reproduced images may be copyrighted and even if not, someone might feel agrieved that they circulate on the web. The images linked by thumbnails are legitimate to use for personal educational purposes with credit and the thumbnail link gives the credit and link to the source if needed.

  1. Ptolemy with an Armillary Ptolemy with an Armillary.

  2. A simple epicycle model A simple epicycle.

  3. Epicycle model with equant An epicycle model with equant.

  4. Ptolemy's magnitude system Ptolemy's magnitude system.

  5. Venus phases Venus phases in the models of Ptolemy and Copernicus.

  6. Ptolemy King From a 15th century book: using an astrolabe and wearing a crown. In Medieval and Renaissance times Ptolemy (circa 100--175) was identified with the Macedonian Ptolemaic kings of Egypt (the family of Cleopatra).
  7. A medieval or Renaissance depiction with a cross staff (?).
  8. Ptolemy A bas-relief from where?
  9. An Epicycle Ptolemy was the master of epicycle models. They were invented by Apollonios of Perga in the 3rd century BC. They were used by Indian, Islamic, and European astronomers. Kepler dropped them from the solar system, but as an approximation they re-appeared in Galactic orbital models.
  10. Ptolemy with a Cross Staff Probably a Renaissance portrait. Credit: ???? (but believed to be public domain); download site: The Galileo Project image gallery.
  11. Ptolemy with an Armillary Ptolemy with an Armillary. The wood scuplture by Joerg Syrlin the elder (15th century).