《不列颠百科全书》：
Ptolemy, Latin in full Claudius Ptolemaeus, (born c. 100 CE—died c. 170 CE), an Egyptian astronomer, mathematician, and geographer of Greek descent who flourished in Alexandria during the 2nd century CE. In several fields his writings represent the culminating achievement of Greco-Roman science, particularly his geocentric (Earth-centred) model of the universe now known as the Ptolemaic system.
