At the forefront of the pioneers in the field was the Greek mathematician and philosopher Claudius Ptolemaeus ( c.AD90 ? 168 ), more popularly known to history as Ptolemy .
这一领域的先驱中最早的是希腊数学家和哲学家克劳迪•托勒密（约公元90年～168年），历史上多称他托勒密。
Claudius Ptolemaeus