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Eudoxos of Knidos, fl. 375 BC

Assignments

1. Review Lindberg's account of Eudoxos (2007, pp. 86-92; 1992, pp. 89-95).
    
2. Optional: Skim this summary of the life and works of Eudoxos provided by the MacTutor Archive of the University of St. Andrews' Mathematics Department.
    
3. Study Michael Crowe, Theories of the World, pp. 21-25 (sections "Introduction" through "Heraclides of Pontus").
    
• Note especially Crowe's concluding paragraph evaluating the question whether Eudoxos believed his models were physically real.
   
  In conjunction with this question, remember the comment of Asger Aaboe you previously encountered:
   
  The famous “hippopede” mechanism of Eudoxus of Knidos could not do what many historians claim; it failed to provide a basis for predicting retrograde motion. Indeed, it could not even qualitatively account for retrograde motion of Mars. Asger Aaboe explains: “It can, however, be shown that this motion [along the ecliptic] is so fast that no matter what the inclination between the axes of the first two spheres we choose... Venus just cannot become retrograde. Precisely the same holds for Mars.... I wish to emphasize this point strongly because I believe it reveals that the purpose of these models was to serve as a qualitative description of planetary motion. Indeed, it cannot be anything else.... [Eudoxus’] “models for Venus and Mars will fail most drastically by their inability to produce retrograde motion, one of the most conspicuous phases of planetary behaviour, and the very phenomenon, I suspect, that the models were created to account for. There are other difficulties in putting these models to use, e.g., that all retrograde arcs for a planet that does become retrograde are of equal length, and that the mathematical techniques (spherical trigonometry) necessary for deriving numerical results from them were not created until some two centuries after Eudoxos.”
  Asger Aaboe, "Scientific Astronomy in Antiquity," Philosophical Transactions of the Royal Society of London, 1974; 276: 39.
   
4. View a javascript animation of a modern reconstruction of Eudoxos' model of the hippopede by Craig Sean McConnell (scroll down to find the Eudoxan model).

	HSCI 3013. History of Science to 17th century Kerry Magruder, Instructor, 2004-14 Brent Purkaple, TA Report typos or broken links	Go to this course at Janux spellcheck.net | wordcounter.net Many thanks to the pedagogical model developed in Mythology and Folklore and other online courses by Laura Gibbs, which have been an inspiration for this course.	Academic Calendar
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