When the renaissance was beginning in Italy, there had bee an interest in astronomy growing in the Palaiologan Roman world just as it was growing elsewhere in the Europe. Just as in other fields of learning, the medieval Romans served as preservers of ancient knowledge. However, they did more than that as well. They did study these things, at different levels during their history – they did not preserve it for us – they preserved it for themselves!
Medieval Roman higher education included the study of astronomy. Much of their understanding of astronomy followed “ancient science, mainly based on Aristotle and Plutarch” and Ptolemy. Astronomical knowledge seems to have grown again in the later centuries of the Empire.
Even during times where the state struggled, or was in diminished circumstances, astronomy could receive imperial patronage. “The emperor John Vatatzes (1222–1254), made great effort to restore a high level of scientific teaching, which was exemplified by Nikephoros Blemmydes and would prepare the ground for the extraordinary renewal of the Palaiologan period. Two generations later, around 1310, Theodore Metochites wrote in a pamphlet against ignorant scholars (namely, his enemy Nikephoros Choumnos) that one cannot presume to have astronomical knowledge from the simple fact that one is able to explain eclipses of the Sun by the interposition of the Moon and eclipses of the Moon by the interposition of the shadow of the Earth. These observations, he says, are so obvious that fishes themselves would expound them if they were able to speak! According to Metochites, one can boast about astronomical knowledge only if one has studied Ptolemy and is able to predict, based on his tables, exactly when and where eclipses will occur, as well as other astronomical phenomena.”
“The study of astronomy normally began with the reading of the elementary treatises written by ancient authors on the celestial sphere, those On the Moving Sphere and On Risings and Settings by Autolykos of Pytane; the Distances of the Moon and the Sun of Aristarchos of Samos; the Introduction to the Phenomena of Geminos; the Spherika, the Habitations, and Days and Nights of Theodosios of Tripoli; the On Circular Motion of Kleomedes; the Mathematics Useful for Reading Plato of Theon of Smyrna; the Anaphorikos of Hypsikles; the Phenomena of Euclid; and others. Thanks to these works, Byzantine students could learn about the basic form of the celestial sphere and its main circles (ecliptic, equator, meridian, tropics), the geometry and theorems of the moving sphere, the motion of the Sun, the equinoxes and solstices, the risings and settings of the stars, and other basic notions. Such knowledge was considered the first step in astronomical studies, and one can see that these treatises were carefully copied in many manuscripts from the 9th and 10th centuries until the end of the empire.”
Mathematical astronomy was the most important. “This part of astronomy was the most important, because it enabled one to make calculations. For it one could use the magisterial work of Ptolemy, who had established in Alexandria the basis of astronomical research…The most important work by Ptolemy was the Mathematical Syntaxis, which Greeks and Byzantines called “the Great Syntaxis” and Arabs al-majisti, an appellation derived from Greek μεγίστη (megiste), “the Greatest”, which became in Latin Almagestum. In this work, Ptolemy proposes complicated constructions based on combinations of circles (eccentrics and epicycles) in order to reproduce the irregular apparent motions of the stars while maintaining Plato’s and Aristotle’s postulate of circular and uniform movements. He relies on numerous observations coming from the Babylonians and his Greek predecessors such as Meton, Timocharis, and Hipparchos, and on his own observations.”
Some people seem to think that the Eastern Romans were not interested in science, and attribute that more to the Arabs. But it is not true that they did not engage with science, in fact they preserved most surviving Ancient Greek scientific texts for us as well as engaging with them. Their intellectual history is fascinating!
Sources:
The Cambridge Intellectual History of Byzantium – Chapter 11 Astronomy by Anne Tihon
shadowsofconstantinople.com 