Claudius Ptolemy- Great Astronomer or Plagiarist?

Many amateur astronomers today may not even recognize the name of Claudius Ptolemy, but the field of astronomy owes this man’s work a huge thank you. That is… according to some scholars. Others, however, think he was nothing more than a common thief.

His work, Almagest, is the oldest surviving star chart. In his 13 volume work Ptolemy puts forward a mathematical model to fit his observational data that was much more sophisticated than any known at that time. Almagest still holds the record for the longest used scientific text ever. Almagest was considered so important that the text was translated into Arabic 500 years after it was written. The translated book was found in the great libraries of Cordova and Toledo, Spain. Many consider Claudius Ptolemy one of the greatest astronomers of history.Ptolemy’s theory saw the earth as the center of the universe. All of calculations of how the planets moved were based on this fact.

Many scientists, including Isaac Newton, felt that Ptolemy was a plagiarist. They felt that Ptolemy had simply copied the work of Hipparchus of Rhodes, occasionally changing a minor number. Then he claimed the work as his own. Other scholars argue that Ptolemy simply had a deep respect for Hipparchus and that the work of Hipparchus had an important impact on Ptolemy.

What do you think? Was Ptolemy a great astronomer or a plagiarist?

Claudius Ptolemy. (n.d.). Retrieved February 25, 2012, from

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