Astronomy. Almagest (from the corrupted Arabic for ‘The greatest’, by which the Arabs compared this work with ‘lesser’ or ‘minor’ astronomies. From most extant Greek manuscripts, we properly call it the ‘Mathematical Composition’). Handy Tables. Planetary Hypotheses. Canobic Inscription. Mathematical Works. Analemma. Planisphaerium. Geography. Geography. Physics. Optics On Weights (lost) Astrology. Tetrabiblos (Bible of Astrology). […]
Simplified Ptolemiac Scheme
This diagram represents a simplified version of the Ptolemaic planetary model. It makes no attempt to illustrate relative sizes, distances, or centers of motion. For all that, it clearly shows several basic features seldom mentioned in 20th-century textbooks. First, note the ‘sun- linked motions’ of Mercury and Venus. Here Ptolemy imagined the center of the […]
Summary of Ptolemaic Astronomy
The following note is restricted to the most basic problems which Claudius Ptolemy solved in his earliest astronomical treatise, the Mathematical Composition, or Almagest (c. 141 A.D.). Two basic points are clear: Ptolemy’s treatment was indeed adequate in terms of the observational data and limitations (pre-telescopic) of his time; Ptolemy chose to focus on problems which could be solved […]
Development of Ancient Astronomy
Post-Classical Science: an Overview
Alexandrian-Hellenistic Science The Museum of Alexandria and the institutionalization of knowledge. Center of Classical research which provided the beginnings of institutional science. Emphasis placed on scholarship and textual criticism. Strong neo-platonic bent (that is, more mystical interpretation of Plato) Important scientific thinkers. Ptolemy: synthesis of mathematical-observational astronomy. Diophantus: development of algebra. Galen: medical thought, anatomy, […]
Chronology – Transmission of Greek Learning to the Middle Ages
Greek Learning to Islam: 325 B.C. – Eastward spread of Greek culture begins. 431 A.D. – Council of Ephesus; Nestorians declared heretics. 529 – Scholars from Plato’s Academy (closed by Justinian) invited to Jundi- Shapur. 632 – Death of Muhammed; spread of Islam. 749 – New Muslim dynasty (Abbasids) patronize translation. 850 – Hunain ibn […]
Read more "Chronology – Transmission of Greek Learning to the Middle Ages"
Ancient Manuscript Sources
Earliest Extant MSS of Classical Authors. The following list, taken in part from information in F. W. Hall, A Companionto Classical Texts (Oxford, 1913) gives some sense of the lateness of our earliest manuscripts of selected classical authors. It should not be inferred that these are necessarily the ‘best’ texts. In many cases the ‘preferred’ […]
Jean Buridan on the Diurnal Rotation of Earth
BOOK, II, QUESTION 22. It is sought consequently whether the earth always is at rest in the center of the cosmos . . . This question is difficult. For in the first place there is significant doubt as to whether the earth is directly in the middle cf the cosmos so that its center coincides […]
Nicole Oresme on the Book of the Heavens and the World of Aristotle
BOOK II. CHAPTER 25. Afterwards he [Aristotle] sets forth another opinion. Text: And some say the earth is at the center of the universe and revolves and moves circularly around the pole established for this, as written in Plato’s Timaeus. Gloss: This was the opinion of one called Heraclides of Pontus who proposed that the […]
Read more "Nicole Oresme on the Book of the Heavens and the World of Aristotle"
Physically Real Planetary Models in the Middle Ages
In antiquity, the task of the astronomer was ‘to invent hypotheses by which the phenomena will be saved (that is, accounted for).’ The principal examples in antiquity of attempts to transcend this limitation and produce physically real astronomical systems were the adaptation of Eudoxus’s system of homocentric spheres by Aristotle, and the Planetary Hypothesis of […]
Read more "Physically Real Planetary Models in the Middle Ages"