Okay, so who was Ptolemy?
Claudius Ptolemaeus, known to us as Ptolemy, was a Greek mathematician, geographer, astronomer and astrologer who
lived in the Hellenistic culture of Roman Egypt. It is likely he was born in or around Alexandria
in Egypt where, among other scientific pursuits, he made astronomical observations. Little
is actually known about his life.
Among his known surviving works was one
with great
import to astronomy, the Almagest (‘The Great Treatise’). In this he compiled and
extended the
astronomical knowledge and theories of the ancient Greek and Babylonian
world. According to Ptolemy, the Greeks recognized forty-eight constellations. Twenty-one are
northern; twelve are Zodiacal and fifteen southern.