which country does he belong to?
Greece.
Ptolemy
"Ptolemaeus" ( "Ptolemaîos") is an ancient Greek personal name.
what is serpens? A constellation of the northern hemisphere. who discovered it? Ptolemy. who was he? A mathematician, astronomer and astrologer. what kind of researches had he carried out? He estimated the Sun was at an average distance of 1,210 Earth radii. has his researches been published ? Yes, "Almagest". how is he associated with music? He wrote "Harmonics", on music theory. what is the former research work based on ? The apparent motions of the stars and planetary paths. when was it published? 2nd-century. how different is his planetary model from the conventional one? It was geocentric and was almost universally accepted until the appearance of simpler heliocentric models during the scientific revolution. who proposed heliocentric model? UNANSWERABLE
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Ptolemy [SEP] Naming and nationality
"Ptolemaeus" ( "Ptolemaîos") is an ancient Greek personal name. It occurs once in Greek mythology and is of Homeric form. It was common among the Macedonian upper class at the time of Alexander the Great and there were several of this name among Alexander's army, one of whom made himself pharaoh in 323 BC: Ptolemy I Soter, the first pharaoh of the Ptolemaic Kingdom. All subsequent pharaohs of Egypt until Egypt became a Roman province in 30 BC, ending the Macedonian family's rule, were also Ptolemies. The name "Claudius" is a Roman name, belonging to the "gens" Claudia; the peculiar multipart form of the whole name Claudius Ptolemaeus is a Roman custom, characteristic of Roman citizens.