How can we objectively assess the contribution to astronomy of a person whose major writing is commonly dubbed ‘The Greatest,’ whose theories held sway over astronomical thought for 1,500 years, but which are now judged as putting astronomers on the wrong path for all those years?
Claudius Ptolemy, usually just known by his surname, was born in about 100 CE and lived and died near Alexandria in Egypt. He may have been a Roman citizen (hence the ‘Claudius’). He was prolific, writing a dozen books that have survived, covering geography, mathematics, astrology, music theory and philosophy. But half of his writings dealt with astronomy.
The best known, and most influential, was the Almagest, though its official title is Mathematical Synthesis. In it, he sought to sum up what was known…
