If one were an astronomer in the closing days of the Roman Empire, say, around 400 A.D., his or her main reference book would have been
A) Ptolemy's Almagest.
B) Plato's Republic.
C) Aristotle's Metaphysics.
D) Galileo's Dialogue Concerning the Two Chief World Systems.

Question

Quizplus · Accepted Answer

Ptolemy's Almagest, written in the 2nd century AD, was the authoritative astronomical text for centuries, including the period around 400 AD. It provided a comprehensive system of the movements of the stars and planetary paths, based on the geocentric model of the universe.

If One Were an Astronomer in the Closing Days of the Roman